2025 ESPEN指南：外科手术中的临床营养（更新版）

ESPEN guideline on clinical nutrition in surgery – Update 2025

Arved Weimann a,*, Mihailo Bezmarevic b, Marco Braga c, M. Isabel T.D. Correia d, Pamela Funk-Debleds e, Luca Gianotti, Chelsia Gillis B, Martin Hübner h, Jesus Fernando B. Inciong i, Mohammad Shukri Jahit j, Stanislaw Klek k, Takayuki Kori l, Alessandro Laviano m, Olle Ljungqvist e, Dileep N. Lobo o, Carmelo Loinaz Segurola p, Isacco Montroni q, B. Ravinder Reddy r, Nicole M. Saur s, Anna Schweinlin f, Han-Ping Shi u, Hiroya Takeuchi r, Dan L. Waitberg w, Ola Wallengren, Paul E. Wischmeyer y, Dirk Ysebaert z, Stephan C. Bischoff t

a Clinical Nutrition Unit, Department of General, Visceral and Oncological Surgery, St. George Hospital, Leipzig, Germany b Department of Hepatobiliary and Pancreatic Surgery, Clinic for General Surgery, University of Defense, Military Medical Academy, Belgrade, Serbia c School of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy d Medical School, Universidade Federal de Minas Gerais and Eterna - Rede Mater Dei, Belo Horizonte, Brazil e Département de Soins de Support, Centre de Lutte Contre le Cancer Léon Bérard, Lyon, France f School of Medicine and Surgery and Pancreatic Surgery Unit, IRCCS Fondazione San Gerardo, University of Milano-Bicocca, Monza, Italy 8 School of Human Nutrition and Departments of Surgery and Anesthesia, McGill University, Montreal Canada h Department of Visceral Surgery, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland i Institute of Surgery, Luke's Medical Center - College of Medicine, Quezon City, Philippines National Cancer Institute, Putrajaya, Malaysia h Surgical Oncology Clinic, The Maria Sklodowska-Curie National Cancer Institute, Krakow, Poland 1 General Surgery, Tone Central Hospital, Numata, Japan and Maebashi Institute of Technology, Maebashi, Japan m Department of Translational and Precision Medicine, Rome, Sapienza University, Italy m Department of Surgery, Orebro, Orebro University, School of Medical Sciences, Sweden

$^{3}$Department of Translational and Precision Medicine, Rome, Sapienza University, Italy

$^{a}$Department of Surgery, Orebro, Orebro University, School of Medical Sciences, Sweden $^{b}$Department of Hepato-Puncreato-Biliary and Abdominal Transplantation Surgery, Hospital Universitario 12 de Octubre and Computense University of Madrid, imas12 Research Institute, School of Medicine, Madrid, Spain, USA

$^{8}$Department of Surgery – Baliardo-Baliardo and Translational Transplantation Surgery, Hospital Universitario 12 de Octubre and Computense University of Madrid, imas12 Research Institute, School of Medicine, Madrid, Spain, 2024, May 8, 2024, 2025, 2026, 2027, 2028, 2029, 2028, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 2029, 20

$^{6}$Department of Surgery, Colon and Rectal Surgery, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy

$^{5}$Department of Surgery, University of Pennsylvania, Philadelphia, PA, USA

$^{1}$ Institute of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany

$^{1}$Department of Gastrointestinal Surgery, Department of Clinical Nutrition, Beijing Shijitan Hospital, Capital Medical University, and National Clinical Research Center for Geriatric Diseases, Xuanwu Hospital, Capital Medical University, Beijing, China

$^{p}$ Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan

$^{2}$Gastroenterology Department at the School of Medicine, University of Sao Paulo, Laboratory Research LIM-35 HC-FMUSP, Sao Paulo, Brazil

$^{2}$Department of Medical Specialties, Clinical Nutrition Unit, Sahlgrenska University Hospital, Region Västra Götaland, Gothenburg, Sweden

$^{2}$Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu Japan, Paulo, Laboratory Research LIM-35 HC-FMUSP, Sao Paulo, Brazil

Abbreviations: ADL, activities of daily living; BIA, bioelectrical impedance analysis; BM, biomedical endpoint; BMI, body mass index; CCI, Comprehensive Complication Index; CFS, Clinical Frailty Scale; Crl, credible interval; CRP, C-reactive protein; CT, computed tomography; CVC, central venous catheter; DHA, docosahexaenoic acid; DT, Distress Thermometer; DXA, dual X-ray absorptiometry; E-SPN, early parenteral supplementation; ECOG-PS, Eastern Collaborative Oncology Group-Performance Status; EN, enteral nutrition; EPA, eicosapentaenoic acid; ERABS, Enhanced Recovery After Bariatric Surgery; ERAS, Enhanced Recovery After Surgery; fTRST, Flemish-triage risk screening tool; G-8, geriatric 8; GAI, Geriatric Anxiety Inventory; GDRS, Groningen Distress Rating Scale; GDS, Geriatric Depression Scale; GLIM, Global Leadership Initiative on Malnutrition; HE, health care economy endpoint; HEN, home enteral nutrition; HMB, hydroxymethylbyrate; HOMA, homeostatic model assessment; IADL, Instrumental Activities of Daily Living; ICU, intensive care unit; IE, integration of classical and patient-reported endpoints, multidimensional endpoints; IL-6, interleukin 6; JBI, Joanna Briggs Institute; L-SPN, late parenteral supplementation; LCT, long-chain triglyceride; LOS, length of stay; MCT, medium-chain triglycerides; MFI, modified frailty Index; MM, mini-mental state examination; MNT, medical nutrition therapy; MPT, multidimensional prognostic index; MRI, magnetic resonance imaging; NCJ, (fine) needle catheter jeunostomy; NRS, Nutritional Risk Screening; ONS, oral nutritional supplements; PEG, percutaneous endoscopic gastrostomy; PEJ, percutaneous endoscopic jejunostomy; PG-SGA, Patient-generated Subjective Global Assessment; PG-SGA-SF, Patient-generated Subjective Global Assessment short form; PN, parenteral nutrition; POD, postoperative day; PROM, patient-reported outcome measure; POF, postoperative pancreatic fistulas; PUFAs, polyunsaturated fatty acids; QL, quality of life; QUICKI, quantitative insulin sensitivity check index; RAI, Risk-analysis Index; RCT, randomized clinical trial; SARC-F/SARC-CalF, Questionnaire to identify individuals at risk of sarcopenia using the components Strength, Assistance in walking, Rise from a chair, Climb stairs, Falls, eventually enhanced by Calf circumference; SGA, Subjective Global Assessment; SMI, skeletal muscle index; SOP, standard operating procedure; TNFa, tumor necrosis factor alpha.

* Corresponding author. Clinical Nutrition Unit, Department of General, General and Oncological Surgery, St. George Hospital, Delitzscher Str. 141, 04129, Leipzig, Germany.

E-mail address: Arved.Weimann@sanktgeorg.de (Arved Weimann).

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Clinical Nutrition 53 (2025) 222–261

$^{y}$ Department of Anesthesiology and Surgery, Duke University School of Medicine, Durham, NC, USA

$^{2}$ Department of Hepatobiliary, Endocrine and Transplantation Surgery, University of Antwerp, Antwerp University Hospital, Edegem, Antwerp, Belgium

ARTICLE INFO

Article history:

Received 12 August 2025

Accepted 22 August 2025

Keywords: Enhanced recovery after surgery Enteral nutrition Parenteral nutrition Perioperative nutrition Prehabilitation Surgery

SUMMARY

Early oral feeding is the preferred mode of nutrition for surgical patients. Avoidance of any nutritional therapy bears the risk of underfeeding during the postoperative course after major surgery. Considering that malnutrition and underfeeding are risk factors for postoperative complications, nutritional therapy is mandatory for any surgical patient at nutritional risk, especially for those undergoing upper gastrointestinal surgery. The focus of this guideline is to cover nutritional aspects of the Enhanced Recovery After Surgery (ERAS) concept and the special nutritional needs of patients undergoing major surgery, e.g. for cancer, and of those developing severe complications despite best perioperative care. From a metabolic and nutritional point of view, the key aspects of perioperative care include: a) Integration of nutrition into the overall management of the patient, b) avoidance of long periods of preoperative fasting c) re-establishment of oral feeding as early as possible after surgery d) start of nutritional therapy early, as soon as a nutritional risk becomes apparent e) metabolic control e.g. of blood glucose, f) reduction of factors which exacerbate stress-related catabolism or impair gastrointestinal function, g) minimized time on paralytic agents in the postoperative period, and h) early mobilization to facilitate protein synthesis and muscle function.

The guideline presents 44 recommendations for clinical practice in patients undergoing elective and non-elective surgery, including new recommendations for frailty assessment, sarcopenia diagnosis, and prehabilitation. As in the former ESPEN practical guideline, the recommendations were additonthally presented in decision-making flowcharts.

© 2025 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

1. Preliminary remarks – principles of metabolic and nutritional care

The key aspects of perioperative care from a metabolic and nutritional point of view, include the overall management of the patient by:

* Integration of nutritional care into the overall management of the patient

$\bullet$ Tackling nutritional therapy early, as soon as nutritional risk or malnutrition is identified in the preoperative period and continuing in the postoperative period, also considering immunonutrition;

$\bullet$ Avoiding long periods of preoperative fasting by providing a carbohydrate load up to two hours before the operation;

$\bullet$ Re-establishing oral feeding as soon as possible after the operation;

* Starting nutritional therapy early;

* Controlling blood glucose;

* Reducing factors that exacerbate stress-related catabolism or impair gastrointestinal function (e.g., pain);

* Minimizing the time on paralytic agents in the postoperative period;

$\bullet$ Stimulating early mobilization to facilitate protein synthesis and muscle function.

This guideline focuses particularly on the nutritional aspects of the Enhanced Recovery After Surgery (ERAS) concept (Plan A). This relates preoperatively to strategies for preoperative optimization. ERAS guidelines advise the use of oral nutritional supplements (ONS) during the perioperative period [1,2]. Despite the best possible preoperative care, severe postoperative complications related to the surgical procedure may occur, with the possible need for intensive care therapy and even reoperation, requiring special nutritional therapy, including medical nutrition (Plan B).

The authors of this guideline update were committed to striving for rigor and quality according to a well-established and transparent methodology [3–5]. In the hope of implementation, which has to be improved [6], we emphasize physiological knowledge to personalize nutrition in clinical practice.

2. Definitions and classifications

2.1. Nutritional therapy

Synonym: Nutritional support is defined according to the European Society for Clinical Nutrition and Metabolism (ESPEN) consensus [7,8]:

Nutritional therapy is the provision of nutrition or nutrients either orally (regular diet, therapeutic diet, e.g., fortified food, ONS) or via enteral nutrition (EN) or parenteral nutrition (PN) to prevent or treat malnutrition. "Medical nutritional therapy" (MNT) is a term that encompasses ONS, enteral tube feeding (enteral nutrition), and parenteral nutrition" [7]. EN and PN have traditionally been called artificial nutritional support, which is covered now by the term MNT. Nutritional therapies are individualized and targeted nutritional care measures using diet or medical nutritional therapy. Dietary advice or nutritional counseling can be part of nutritional therapy.

2.2. Nutritional "metabolic" risk and disease-related malnutrition

Nutritional assessment before surgical procedures aims to minimize the risks associated with changes in the pathophysiology of the stress response [9]. Malnutrition is generally considered to be associated with starvation and lack of food. Its presence in the Western world, with an increasing percentage of obese people, is frequently neither realized nor well understood. For patients undergoing cancer surgery, malnutrition is an independent risk factor for the development of complications, is associated with increased mortality, and influences the hospital

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length of stay (LOS) and costs [10–14]. Disease-related malnutrition is more subtle than suggested by the World Health Organization (WHO) definition of undernutrition with a body mass index (BMI) < 18.5 kg/m$^{2}$ [8,15]. Disease-related weight loss in patients who are overweight is not necessarily associated with a low BMI. However, this weight loss results in changes in body composition with a loss of fat-free mass contributing to sarcopenia or sarcopenic obesity [16] and inducing a “metabolic risk,” which has to be kept in mind for patients undergoing major surgery with special regard to cancer. Chronic low-grade inflammation may also be a component of or contributor to malnutrition [17].

In 2019, the Global Leadership Initiative on Malnutrition (GLIM) developed a new tool to diagnose malnutrition, which is supported by major professional societies worldwide [18]. After screening for malnutrition, phenotypic and etiologic criteria are collected, which consider unintentional weight loss, low BMI, reduced muscle mass, decreased food intake or absorption, and inflammation.

Here, phenotypic and etiologic criteria are distinguished:

Phenotypic criteria are:

$\bullet$ Non-volitional weight loss

$\bullet$ Low BMI

$\bullet$ Reduced muscle mass

Etiologic criteria are:

$\bullet$ Reduced food intake or assimilation

$\bullet$ Inflammation or disease burden

Ideally, all the criteria should be assessed, but if not possible, at least one phenotypic and one etiologic criterion must be met for the diagnosis of malnutrition. The severity is defined by the phenotypic criteria, of which muscle mass assessment, when available, is relevant.

The GLIM recommendations for assessment of muscle mass include [19]:

$\bullet$ Bioelectrical impedance analysis (BIA)

* Computed tomography of the abdomen (CT)

* Dual X-ray absorptiometry (DXA)

$\bullet$ Ultrasound

$\bullet$ Anthropometric measures (e.g., calf circumference, mid-arm circumference)

CT is a routine procedure in patients with cancer. Muscle mass, and its radiodensity can be determined from the axial image at the level of the third lumbar vertebra (L3), which is representative of the entire muscle mass of the patient [20]. Subcutaneous fat and visceral fat can also be determined. There is a significant association between CT-defined sarcopenia and clinical outcomes in surgical patients with gastrointestinal tumors [21–23]. As this method of body composition analysis is not yet routine in clinical practice, this information will not be available for most patients. Instead, the definition of high metabolic risk of the ESPEN Surgery Working Group might be helpful.

While low BMI alone may be less common to define high metabolic risk [24], the guideline group recommends the presence of at least one of the following criteria:

* Weight loss >10–15 % within six months

$\bullet$ BMI <18.5 kg/m$^{2}$

$\bullet$ Nutritional Risk Screening (NRS) $\ge 5$ or Subjective Global Assessment (SGA) Grade C

* Preoperative serum albumin <30 g/L (without evidence of hepatic or renal dysfunction).

Focusing on the surgical patient, preoperative serum albumin concentration is a prognostic factor for complications after surgery [14,25–31] and may also be associated with impaired nutritional status. However, serum albumin concentration is not modifiable by short-term nutritional therapy and should not be used as a nutritional marker anymore [32]. Nevertheless, serum albumin concentration might still serve to define surgical patients at high metabolic risk. This concept aligns with the current Joint Consensus Statement on Nutritional Screening and Therapy within a Surgical Enhanced Recovery Pathway of the American Society for Enhanced Recovery and Perioperative Quality Initiative [33]. Furthermore, albumin and C-reactive protein (CRP) are well-established parameters in the (modified) Glasgow Prognostic Score for postoperative complications and survival in patients with cancer [34–36]. C-reactive protein measurement has been also recommended for the etiologic GLIM criteria [37]. Procalcitonin has been proven to predict complications, e.g., anastomotic leak and EN tolerance in the critically ill [38–41].

3. Methodology

3.1. General methodology

The present guideline was developed according to the standard operating procedure (SOP) for ESPEN guidelines [5]. GRADE methodology was used for the evidence assessment [42]. The guideline is an updated version of the "ESPEN guideline: Clinical nutrition in surgery" developed in 2017 [2], and updated in German in 2023 [43]. The aforementioned underlying guidelines were developed using the SIGN methodology, which is why this guideline still contains remnants of the SIGN methodology. The present guideline update was developed by an international expert group representing different professions: surgery: M.B., M.B., M.I.T.D.C., L.G., M., H., J.F.B.I., M.S.J., S.K., T.K., O.L., D.N.L., C.L. S., I.M., B.R.R., N.M.S., H.-P.S., H.T., D.L.W., A.W., D.Y., anesthesia: P. E.W., gastroenterology: S.C.B., A.L., P.F-D., dietetics: C.G., O.W., nutrition scientist: A.S. All members of the working group had declared their individual conflicts of interest according to the rules of the International Committee of Medical Journal Editors (ICMJE).

Following the SOP for ESPEN guidelines and consensus papers, the first development step of this guideline was to check the 2017 PICO questions for further applicability and extension. PICO questions are designed to address specific patient groups (or problems), Interventions, compare different therapies, and be outcome-related [5]. In total, the 2025 guideline update consists of 18 PICO questions divided into six main chapters entitled "Basic questions", "Indication for nutritional therapy", "Preoperative nutrition", "Postoperative nutrition", "Bariatric surgery", and "Organ transplantation". To answer these questions, a literature search that covered the period since the last guideline was performed to identify suitable meta-analyses, systematic reviews, and primary studies (for details see below, "search strategy"). Each PICO question was allocated to subgroups, including at least three experts for the different topics, and, initially, 48 recommendations and two statements answering the PICO questions were formulated.

In 2022, ESPEN switched from the Scottish Intercollegate Guidelines Network (SIGN) methodology to the GRADE methodology. As the present guideline is based on previous guidelines developed with the SIGN methodology, the present guideline contains elements from both methodologies.

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For grading and assessment of new literature, the GRADE method was applied. For systematic reviews and meta-analyses, the grading of the quality of evidence was performed for the five domains "Risk of Bias", "Inconsistency", "Indirectness", "Imprecision", "Publication Bias" for all relevant outcomes according to the GRADE handbook [42]. Additionally, summary of finding tables were filled in. When no meta-analysis was possible, a narrative approach was used [44]. Supportive of this, data from every relevant publication were extracted to evidence tables. To evaluate the literature, the AMSTAR II checklist [45] was used for Systematic Reviews, the Cochrane risk of bias tool 2 [46] for randomized clinical trials (RCTs), the Newcastle-Ottawa scale [47] for cohort studies and cross-sectional studies, and the JBI (Joanna Briggs Institute) Critical Appraisal Checklist for Analytical Cross Sectional Studies [48] for the studies concerned. The results of the evaluation are presented in the evidence tables in Appendix A.

For literature originating from previous guidelines, the SIGN grading system was maintained (Table 1). Characteristics of these older publications are also presented in evidence tables. For reasons of continuity, the grade of recommendations of SIGN [40] was maintained. The grades of recommendation were decided according to the levels of evidence assigned (Table 1). These tables are available online as supplementary material to this guideline (see Appendix A supplementary data).

The wording of the recommendations reflects the grades of recommendations since level A is indicated by the use of the word “shall”, level B by the word “should”, and level 0 by the word “can” or “may” (Table 2). This also reflects the strength of recommendation with “shall” meaning a strong and “can/may” meaning a weak recommendation, and “should” lying in between. The good practice points (GPP), taken from the SIGN methodology, are based on expert opinions due to the lack of studies, for which the choice of wording was not restricted. Having the option of an expert opinion is essential in the field of clinical nutrition, where certain topics cannot be addressed by RCTs due to ethical considerations. Supporting the recommendations, the working group added commentaries to explain their basis.

As in the 2017 guideline, outcome parameters for the recommendations were weighed according to the type of evidence-based endpoints: biomedical (BM), multidimensional (IE), health economy (HE), and quality of life (QL) [50]. The QL endpoint was supplemented by patient-reported outcomes (PROMs), e. g. vomiting and nausea. Specifically for the recommendations concerning preoperative fasting or carbohydrate loading, insulin requirements were introduced as an additional endpoint.

Between 26th June and 22nd July 2024, an online voting (Delphi round) on the recommendations was performed using the guideline-services.com platform. All ESPEN members were invited to agree or disagree with the recommendations and to provide comments. A first draft of the guideline was also made available to the participants on that occasion. Thirty-three recommendations

reached an agreement >90 %, 15 recommendations reached an agreement of 75-90 %, one of the statements reached an agreement >90 %, and the other one reached an agreement of 75-90 %. Those recommendations with an agreement >90 % (indicating a strong consensus, see Table 3) were directly passed [51], and all others were revised according to the comments and voted on again during a consensus conference that took place online in two parts on 27th August and 2nd September 2024. Eleven recommendations that originally had received >90 % agreement were also voted on during the consensus conference due to major changes in wording. During the consensus conference, three recommendations were deleted, two recommendations were also merged. Therefore, the final guideline comprises 44 recommendations and three statements. At the consensus conference, all recommendations but two received an agreement >90 %, and one statement that was also voted on received an agreement of 75-90 %.

Three recommendations (20, 27, and 31) underwent major changes after the consensus conference. To be consistent with the other recommendations, the patient group in recommendation 20 was specified as "and/or high metabolic risk". The duration in recommendation 27 was changed from 7-14 days to 10-14 days to align with recommendation 20, although seven days were retained as the minimum. Recommendation 31 was updated to include the need for stable electrolytes to make it more user-friendly. The percentages of agreement given below the recommendations are from the Delphi round and the consensus conference. The majority of the guideline working group agreed with the above recommendations in an e-mail-based voting.

3.2. Search strategy

The literature search was performed by the working group members at the end of January 2024 using the PubMed NCBI and the Cochrane Databases. The search was limited to publications for a three-year period (including publications since 2021) taking into account an overlap with the search for the previous DGEM guideline update in 2021 [43]. A longer period was chosen for the two new topics, prehabilitation and frailty. For all the PICO questions, the literature search was performed between December 2023 and March 2024 by subgroups of the guideline working group, including at least three members. Title and abstract screening, followed by full-text screening, was performed in duplicate, in case of disagreement mediated by the third member.

For the search strategy please refer to Appendix A.

Studies were included if they were systematic reviews, meta-analyses, or RCTs comparing a defined nutritional intervention (as reflected in the search strings) with either no intervention or a standard treatment. If none of the above-mentioned studies were available, prospective and retrospective observational studies, and occasionally case series, were also included. Both elective and emergency surgical procedures were considered. Outcomes had to

Table 1 Definition of levels of evidence.

|1++|High-quality meta-analyses, systematic reviews of RCTs, or RCTs with a very low risk of bias| |---|---| |1+|Well-conducted meta-analyses, systematic reviews, or RCTs with a low risk of bias| |1-|Meta-analyses, systematic reviews, or RCTs with a high risk of bias| |2++|High-quality systematic reviews of case-control or cohort studies. High-quality case-control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal| |2+|Well-conducted case-control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal| |2-|Case-control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal| |3|Non-analytic studies, e.g. case reports, case series| |4|Expert opinion|

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Table 2

Definition of grades of recommendation [5].

|A|At least one meta-analysis, systematic review, or RCT rated as 1++, and directly applicable to the target population; or A body of evidence consisting principally of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results| |---|---| |B|A body of evidence including studies rated as 2++, directly applicable to the target population; or A body of evidence including studies rated as 2+, directly applicable to the target population and demonstrating overall consistency of results; or and demonstrating overall consistency of results; or Extrapolated evidence from studies rated as 1++ or 1+| |0|Evidence level 3 or 4; or Extrapolated evidence from studies rated as 2++ or 2+| |GPP|Good practice points/expert consensus: Recommended best practice based on the clinical experience of the guideline development group|

GPP, good practice point.

Table 3

Classification of the strength of consensus.

|Strong consensus|Agreement of >90 % of the participants| |---|---| |Consensus|Agreement of >75-90 % of the participants| |Majority agreement|Agreement of >50-75 % of the participants| |No consensus|Agreement of <50 % of the participants|

According to the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) (Association of the Scientific Medical Societies) in Germany methodology [50].

align with the pre-defined, prioritized outcome parameters. Only articles published in English or German were included. An update search was performed in January 2025.

After this point, newly published articles that came to the authors' attention were described in the commentary texts, but they had no influence on the recommendations that had already been agreed upon.

Outcome parameters were graded as critical, important, and not important:

$\bullet$ Mortality (critical)

* Complications in general (Clavien-Dindo) (critical)

$\bullet$ Infectious complications (critical)

$\bullet$ Hospital length of stay (important)

$\bullet$ Readmission rate (important)

* Nutritional status and body composition (important)

* Quality of life (important)

3.3. Visualization of the guideline content

To promote the application of the guideline in practice, decision-making flowcharts were created to illustrate the process from the preoperative period to discharge. These flowcharts are intended to facilitate rapid bedside decision-making. First, there is an overview (Fig. 1), followed by the preoperative period (Fig. 2). The postoperative period is divided into general management (Fig. 3) and nutritional therapy (Fig. 4). The final flowchart covers special cases, such as organ transplantation and bariatric surgery (Fig. 5).

4. Basic questions

4.1. Is there a need for standard operating procedures?

Recommendation 1

Standard operating procedures should be used for quality management in the performance of clinical nutrition.

Grade of recommendation GPP – strong consensus 96 % agreement

Comment

The use of nutrition protocols and SOPs has been shown to be beneficial in ensuring the implementation of medical nutritional

therapy and the achievement of nutritional goals [52,53]. The positive impact of a preoperative structured nutritional protocol on clinical parameters was observed in an RCT in 80 patients undergoing major gastrointestinal surgery: serum albumin concentration, earlier onset of bowel function, and initiation of EN [54]. However, the study was not powered for real outcome parameters. A very recent RCT (n = 84) showed, in patients undergoing pan-creatuodenectomy, that a pathway-directed whole-course nutritional management was associated with fewer complications, total and abdominal infections, and was even cost-effective [55].

4.2. Is preoperative fasting necessary?

Recommendation 2

Patients without a particular risk of tracheo-bronchial aspiration shall be allowed to ingest clear liquids up to two hours and solid foods up to six hours before the start of anesthesia (BM, IE, QL).

Grade of recommendation A – strong consensus 100 % agreement

Comment

In recent decades, there has been a growing departure from the dogma of preoperative fasting because there are no benefits from preoperative fasting. The risk of aspiration or regurgitation is not increased with two hours of fasting for liquids compared with twelve hours of fasting. This correlates with the physiologic time of gastric emptying for liquids, which is 60–90 min [56–59]. Accordingly, many national anesthesia societies have revised their guidelines on fasting [60–63] and allow patients to have clear liquids up to two hours before the start of anesthesia for elective procedures. Patients with a “special risk”, such as emergency surgery and patients with delayed gastric emptying [64] or gastroesophageal reflux [58], are exempt from this recommendation. Since the implementation of the guidelines, there have been no reports of an increase in the rate of aspiration, regurgitation, or perioperative pulmonary complications. Minimizing fasting episodes is a key component of the ERAS concept. The ability to consume clear liquids, as well as coffee or tea, reduces thirst symptoms and, consequently, headaches. Solid foods should be permitted six hours before the start of anesthesia and should be easily digestible.

4.3. Is preoperative metabolic preparation by carbohydrate administration useful in elective surgery?

Recommendation 3

Carbohydrate stores should be selectively replenished to trigger insulin release shortly before major elective abdominal surgery to counteract insulin resistance and increase patients' comfort (B) (QL) BM. Specific carbohydrate drinks can be given the evening before and up until two hours before the start of anesthesia to trigger insulin release (0) (BM).

Grade of recommendation B/0 – strong consensus 96 % agreement

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![graph TD\n A1[Elective surgical patient] --> A2[Preoperative patient]\n A1 --> A3[Special cases]\n A2 --> A4[Screening(NRS-2002) and Assessment]\n A2 --> A5[Surgey]\n A3 --> A6[Before transplantation Monitoring]\n A3 --> A7[After transplantation Nutritional therapy]\n A3 --> A8[After bariatric surgery Nutritional therapy]\n A4 --> A9[No/low risk NRS≤4]\n A4 --> A10[High risk NRS≥5 WL≥10% BMI≤18.5 Alb<30]\n A5 --> A11[Postoperative patient]\n A9 --> A12[Oral nutritional therapy]\n A10 --> A15[Postpone surgery at least 10-14 d Consider prehabilitation]\n A11 --> A16[Early oral intake]\n A12 --> A13[Energy needs met by nutritional therapy]\n A13 -->|yes| A14[CHO drink]\n A13 -->|no| A24[General]\n A14 --> A5\n A15 --> A4\n A16 --> A19[Oral intake can be realized as recom-mended]\n A16 --> A26[Oral intake cannot be realized for 5 d （or <50% for 7 d）]\n A17[Consider insertion of NCJ/NJ during surgery] --> A18[Management according to ERAS protocols]\n A18 --> A20[Discharge]\n A18 --> A22[Nutritional therapy]\n A19 --> A18\n A20 --> A1\n A21[Complications cations NJ/NCJ available] --> A20\n A22 --> A23[EN]\n A23 --> A25[If 7d <50%]\n A24 --> A27[Encourage ONS]\n A25 -->|no| A26\n A25 -->|yes| A20\n A27 --> A5\n A28[Energi needs met at discharge] -->|yes| A20\n A28 -->|no| A29[Energy needs met via EN]\n A29 --> A30[Dietary counseling, ONS, consider EN via NCJ, follow up monitoring]\n A30 --> A1\n](1/parseimages/figure60a2a5d3347e4726ace164b9db680ae9_0_2.png)

Comment

The preoperative intake of carbohydrate-containing beverages (so-called “carbohydrate loading”) is part of the ERAS protocol [62]. Preoperative carbohydrate loading changes metabolism before the onset of surgery from an overnight fasted state to a fed state, and this reduces postoperative insulin resistance and impacts postoperative metabolism and recovery [65]. Most studies on the concept have used 800 mL of a 12 % maltodextrin-rich carbohydrate drink given the evening before surgery and a 400 mL dose approximately two hours before the induction of anesthesia. Extensive studies have shown that the risk of tracheo-bronchial aspiration using these doses was not increased [56,66–69] and that gastric emptying was well within the two hours prescribed for clear liquids in most fasting guidelines [58–60,62].

Some physiological aspects should be considered. Intake of carbohydrates causes the release of insulin that initiates anabolic reactions lasting only a few hours. The composition of the drink impacts these reactions. Gastric emptying is faster with lower osmolality drinks, and insulin release is related mainly to the concentration of the carbohydrates and not the overall amount. A 6% sports drink causes almost no insulin release (purposely so), while the same load of carbohydrates as a 12% drink causes a 5-6-fold increase, as seen after a normal meal. The morning dose is a key to the change in metabolism [70]. Not all commercially available drinks have been studied for safety or efficacy. Determinations of the treatment's metabolic and endocrine efficacy should also be measured accurately. In many studies, authors try to determine insulin resistance using methods when insulin is

inactive [71–74]. These methods (homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI)) cannot capture the development of insulin resistance [75]. Insulin sensitivity and resistance are best measured using the hyperinsulinemic-euglycemic clamp at physiological insulin concentrations [65]. If the clamp method is unavailable, it is better to study glucose concentrations associated with the development of complications [76,77]. Studies in major abdominal surgery using the clamp method at physiological levels have shown reduced insulin resistance and support recovery [65,78] while studies using HOMA or QUICKI show variable results.

The above factors impact much of the information gained from available meta-analyses. When mixing different surgical procedures, bundling minor and major surgeries, and adding surgical techniques, the variation in relevant outcomes is further enlarged [66,79–81]. Meta-analysis of such different underlying studies is at least problematic or even inadequate.

There are several RCTs on the outcomes of using carbohydrate treatment. There has been no study reporting major harm from its treatment. In a small prospective RCT with a total of 36 patients undergoing elective colorectal surgery (fasting vs. water vs. maltodextrin solution), the LOS was reduced (study solution vs. water, P = 0.019) [82]. Another study reported that bowel function returned earlier in patients with carbohydrate loading and a one-day shorter LOS [71]. Two early meta-analyses of 21 prospective RCTs with a total of 1685 patients [79] and 27 prospective RCTs with 1976 patients [80] both showed a reduction in LOS after preoperative carbohydrate loading for major abdominal procedures, but not for short stay surgeries (≤2 d). A large network meta-

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![graph TD\n A1[Preoperative patient] --> A2[Screening(NRS-2002) and Assessment]\n A2 --> A3[No/low risk NRS≤4]\n A2 --> A4[High risk NRS≥5 WL >10% BMI <18.5 Alb<30]\n A3 --> A5[Oral nutritional therapy]\n A4 --> A6[Postpone surgery at least 10–14 d Consider prehabilitation]\n A5 --> A7[Energy needs met by nutritional therapy]\n A5 --> A10[General]\n A5 --> A13[GI cancer]\n A6 --> A14[Consider EN/SPN]\n A7 --> A8[CHO drink]\n A7 --> A11[Encourage ONS]\n A8 --> A9[Surgery]\n A10 --> A12[Encourage ONS]\n A13 --> A15[Offer Immuno ONS]\n A14 --> A16[R20: Patients with severe nutritional risk or high nutritional therapy preoperatively(A), even if postoperative surgery(BM).A period of 10–14 days should be considered(B),(A/B, 93%]\n A14 --> A17[R27: Only in those patients with severe malnutrition and/or at high nutritional risk in whom oral/enteral nutrition is not feasible,preoperative parenteral nutrition should be provided(A) for a period of 10–14 days with a minimum of seven days(GPP).(A/GPP, 100%)]\n A15 --> A18[R25: Patients with gastrointestinal cancer should be offered oral/enteral tube immunonutrition, including arginine, omega-3 fatty acids, and nucleotides,preoperatively for five to seven days(BM, HE).(B, 87%]\n A15 --> A19[S2: At present, no general recommendation can be made for or against oral supplementation with glutamine.(BM).(87%)]\n A20[R1: Standard operating procedures should be used for quality management in the delivery of clinical nutrition.(GPP, 96%]\n A21[R2: Patients without a particular risk of tracheo-bronchial aspiration shall be allowed to ingest clear liquids up to two hours and solid foods up to six hours before the start of anesthesia(BM, IE, QL).(A, 100%)]\n A22[R3: Carbohydrate stores should be selectively replenished to trigger insulin release shortly before major elective abdominal surgery(BM).Specific carbohydrate drinks can be given the evening before and up until two hours before the start of anesthesia to trigger insulin release(0)(BM)(B/0, 96%)]\n A23[R6: Nutritional status should be routinely assessed when major surgery is planned in order to guide perioperative nutritional therapy.(GPP, 100%)]\n A24[R7: In surgical patients with cancer, body composition should be assessed.]\n A25[R8: A frailty assessment should be performed in older patients undergoing major surgery since frailty is associated with poor postoperative outcomes.(GPP, 93%)]\n A26[R9: Nutritional risk should be assessed when CT software is available, it should be used as a gold standard.(B, 100%)]\n](1/parseimages/figure37a6db6be00c43b1850288b8dc9dfade_0_2.png) analysis bundling 43 small, medium, and major surgeries and 3110 patients reported a slight reduction in LOS compared with the fasting group. However, it showed no advantage compared with water or placebo [66]. Avoiding the limitations of the basic studies and the weakness of bundling short and long-term surgeries, a meta-analysis with a more limited focus, such as only major abdominal surgery RCTs [83] or a sub-analysis in another meta-analysis [66], shows reduced LOS.

In elective colorectal surgery, carbohydrate loading positively affected postoperative weight and muscle mass preservation [84], and another study reported a reduction in interleukin-6 (IL-6) concentrations [71]. The two largest RCTs on carbohydrate loading performed by Gianotti et al. [85] and Savluk et al. [86] demonstrated a significant reduction in insulin requirements and an improvement in patient well-being with carbohydrates. In contrast, in cardiac surgery, two studies failed to confirm a similar impact of preoperative carbohydrates [87,88]. Despite reports showing associations between insulin resistance, hyperglycemia, and complications [66] and the effectiveness of preoperative carbohydrates to minimize insulin resistance and control glucose concentrations, there are no convincing data to show a reduction in major complications [66]. However, in one study in cardiac surgery, the need for inotropic support was significantly reduced in the carbohydrate-treated group [87].

Oral carbohydrate administration is reported to yield an improvement in recovery and postoperative well-being in several studies of different open and laparoscopic surgeries, including colorectal [89–94]. In elective cholecystectomy, a reduction in postoperative nausea and vomiting by carbohydrate drinks was

reported compared with fasting patients, while another study found no difference when compared with placebo [95,96]. Other studies reported no benefit for postoperative pain or quality of recovery [97,98]. An extensive study in thyroid surgery reported an improvement in postoperative symptoms in the carbohydrate group in a range of parameters [99], while a smaller study demonstrated an improvement in well-being and patient satisfaction [94]. In thoracic and bariatric surgery, carbohydrates improved nausea and reduced analgesic requirements [100,101]. In neurosurgical patients, glucose homeostasis, hand grip strength, and lung function improved. In elderly patients undergoing hepatectomy, an RCT showed lower overall concentrations of inflammatory response mediators (CRP, IL-6) postoperatively, and lower patient self-reported symptoms of thirst, hunger, anxiety, and nausea, shortened times to first flatus and first defecation by approximately two to three days, respectively [102]. Furthermore, an RCT of patients with a planned Cesarean section showed an improvement in well-being [103].

Preoperative carbohydrates were initially investigated using an intravenous infusion of glucose at a rate of 5 mg/kg/min of a 10 % glucose solution. This treatment, given overnight, causes a rise in insulin concentrations seen after a meal and causes a reduction in postoperative insulin resistance [104] and fewer protein losses [105]. However, because of the discomfort of an overnight infusion of a high osmolar solution and the ease of a drink, this treatment is not used regularly in practice but could serve as an alternative if the patient is unable to drink.

There are also studies where carbohydrates have been mixed with other ingredients. In one RCT, patients with gynecologic

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![graph TD\n A1[Surgery] --> A2[Postoperative patient]\n A1 --> A7[Consider NG/J/NJ insertion during surgery]\n A2 --> A3[Early oral nutrition]\n A3 --> A4[Oral intake can be realized as recom-mended]\n A3 --> A6[Oral intake cannot be realized for 5 d （or <50% for 7 d）]\n A4 --> A5[Management according to the ERAS protocols]\n A5 --> A8[Discharge]\n A5 --> A9[Nutritional therapy]\n A6 --> A9\n A7 --> A5\n A9 --> A10[Figure 4]\n A11[R9: In patients who are not expected to be able to take oral nutrition for five days or longer perioperatively, nutritional therapy should be started immediately with special regard to malnourished patients. Nutritional therapy should be started immediately, also in patients who were unable to have an oral intake of more than 50% of the recommended amount of energy for more than seven days. (GPP, 93%)]\n A12[R6: Nutritional status should be routinely assessed when major surgery is planned in order to guide perioperative nutritional therapy. (GPP, 100%)]\n A13[S1: Preoperative nutritional status, postoperative course including recovery, complications, length of hospital stay, and in-hospital oral intake define post-discharge nutritional therapy and follow-up. (100%)]\n A14[R1: Standard operating procedures (SOPs) should be used for quality management in the delivery of clinical nutrition. (GPP, 96%)]\n A15[R4: Oral/Tube feeding shall be started as soon as possible within the first few hours after surgery, in conscious and hemodynamically stable patients as tolerated (BM, IE, A, 100%)]\n A16[R5: The oral diet should be adapted to the type of surgical procedure and individual tolerance. Tolerance of early oral nutrition shall be assessed carefully in patients after operations with a high risk for delayed gastric emptying or postoperative ileus. (GPP, 93%)]\n A17[R30: In patients with malnutrition and/or high nutritional risk, intraoperative placement of a nasojejunal tube or feeding jejunostomy should be considered, especially during esophagectomy, total gastrectomy, and pancreatoduodenectomy(BM). (B, 89%)]\n](1/parseimages/figurede01e01f29b94a879f0eac59c12247d0_0_2.png) tumors were treated with carbohydrates and whey protein before surgery, and early feeding after surgery had better hand strength, a higher percentage of preserved muscle mass, a lower CRP/albumin ratio, and significantly better postoperative bowel function [106]. In pancreatic resections, preconditioning with glutamine, antioxidants, and green tea extract yielded a significant increase in plasma vitamin C concentration and an uplift in endogenous antioxidant capacity compared with the placebo group, without, however, improving oxidative stress and the inflammatory response [107].

In patients undergoing laparoscopic cholecystectomy, carbohydrate + glutamine supplementation showed a benefit in antioxidant status (serum glutathione concentration) and inflammatory response (serum IL-6 concentration) [71,72].

The use of homemade products such as sweetened tea has not yet been investigated in controlled studies. However, a small study of healthy volunteers showed that commercially available fruit-based soft drinks can empty the stomach almost entirely within two hours of intake. However, it did not result in the same level of insulin release compared with the drink most commonly studied for preoperative use [108].

There is limited evidence from RCTs for the use of preoperative carbohydrates in patients with diabetes [87,109–111]. According to a systematic review including 14 studies (seven RCTs), carbohydrate loading is safe for patients with well-controlled type 2 diabetes [112]. To prevent potential harm from carbohydrate administration, this concept should hence not be used in patients with severe diabetes, and especially not in suspected gastroparesis.

In summary, in major surgical procedures, oral carbohydrate loading minimizes postoperative insulin resistance, improves glucose control postoperative and well-being, and potentially

shortens LOS [83]. The treatment can generally be recommended to improve patient well-being based on low-quality data, for major surgery to control glucose, and for reducing insulin resistance and its potential effect on recovery.

4.4. Is a break in oral/enteral nutrition intake necessary in principle after a surgical procedure?

Recommendation 4

Oral/tube feeding small be started as soon as possible within the first few hours after surgery, in conscious and hemodynamic stable patients as tolerated (BM, IE).

Grade of recommendation A – strong consensus 100 % agreement

Comment

Oral nutrition (balanced hospital diet and/or ONS) can, in most cases, be resumed immediately after surgery in neurologically and hemodynamically stable, fully conscious patients with no signs of bleeding. To be hemodynamically stable, patients should show adequate fluid resuscitation, normal or decreasing lactate, normal mixed venous oxygen ($MVO_2$) saturation, and stable or decreasing vasopressors. For both cholecystectomies and colorectal re- sections, neither esophagogastric decompression nor delayed oral feeding has been shown to have a beneficial effect [113–115]. Early oral or enteral feeding, including clear liquids on the first or second postoperative day (POD), did not cause any limitation of anastomotic healing in the colon or rectum [115–120] and rather led to a significantly shorter LOS [121–124]. This has been confirmed by a Cochrane review, with 17 prospective RCTs and 1437 included patients undergoing lower gastrointestinal tract surgery [125].

Several meta-analyses demonstrate significant benefits in terms of complication rates in general [124,126,127], but also

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![graph TD\n A1[Nutritional therapy] --> A2[EN]\n A2 --> A3[If 7d <50%]\n A3 -->|no| A4[Energy needs met at discharge]\n A3 -->|yes| A5[SPN]\n A4 -->|yes| A6[Discharge]\n A4 -->|no| A7[Dietary counseling, ONS, consider EN via NCJ, follow up monitoring]\n A7 --> A6\n](1/parseimages/figure56bffd12955e4bac9ca04940fedcaca4_0_2.png) specifically in terms of wound infections, intra-abdominal abs- scesses, as well as anastomotic insufficiency [124,127]. One showed that early oral feeding increased vomiting [128].

Early oral feeding is also a central component of ERAS, with significantly fewer complications and a reduction in LOS in several meta-analyses [129–139]. Even without participation in an ERAS program, early oral feeding shortens LOS [140].

Compared with a traditional diet, a free diet on POD2 after surgical procedures shortened the time to oral food tolerance without a higher rate of gastric tube reinsertion. No differences were found regarding the duration of postoperative ileus [129,141].

Recent studies suggest that early oral nutrition reduces the postoperative stress response as measured by the concentrations of circulating proinflammatory cytokines [142].

Even after gastrectomy, not using a feeding tube resulted in a reduction in LOS [143]. A meta-analysis of 15 studies (including eight RCTs) involving 2112 patients with upper gastrointestinal tract surgery also yielded a shortening of LOS in the early oral feeding group, and the complication rate, particularly the rate of anastomotic insufficiency, was not different [144].

Although early oral feeding after esophageal resection is controversial [145], current data suggest that even in this context, an early oral diet is at least equivalent to oral food restriction with EN. Recent studies [146–148] show that early oral feeding after minimally invasive thoracic esophagectomy is safe and does not impact complication rates. In addition, early oral feeding has been shown to result in a faster initiation of bowel activity and a

shortened LOS [149], as well as improving short-term quality of life [150].

In open esophageal surgery, as well as in cervical anastomosis, the situation remains unclear. Two retrospective studies [151,152] suggest that early oral feeding increased leak rates. An investigation based on high-quality studies is needed before the safe use of early oral feeding can be made for these patients [153,154].

In pancreatic surgery, the implementation of ERAS has been shown to reduce the complication rate and shorten LOS [138]. In a multicenter RCT, it was demonstrated that oral nutrition did not lead to an increased incidence of postoperative pancreatic fistulas (POPF), nor was it equal to EN with regard to the healing of POPF [122]. Oral feeding is also possible in patients with POPF without risk of clinical deterioration, with prolongation of the need for drainage and prolonged LOS [155].

A meta-analysis in patients undergoing urological surgery could show that early EN leads to a significant reduction in the rate of infectious complications as well as in costs compared with PN [127].

Comparing open surgery with laparoscopic surgery, oral food intake is better tolerated in the latter due to an earlier return bowel function [156–158]. In combination with ERAS, no differences were found between laparoscopic and open colon surgery with full implementation of the program [159]. In a multicenter RCT, LOS was significantly shorter with laparoscopic surgery [160]. A recent meta-analysis confirmed the benefits of combining ERAS and laparoscopic surgery in terms of morbidity and LOS [161].

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![graph TD\n A1[Special cases] --> A2[Before transplantation Monitoring]\n A1 --> A3[After transplantation Nutritional therapy]\n A1 --> A4[After bariatric surgery Nutritional therapy]\n A2 --> A5[R38: In cases of malnutrition, nutritional status shall be optimized before organ transplantation.(BM).(A, 100%)]\n A2 --> A6[R40: Follow-up visits of patients on the transplant waiting list should also include assessment of nutritional status.(GPP, 100%)]\n A2 --> A7[R37: Recommendations for the living donor and recipient are no different from those for patients undergoing major abdominal surgery.(GPP, 100%)]\n A2 --> A8[R39: In cases of malnutrition, a structured nutrition plan should be implemented first, followed by supplementation with ONS or enteral nutrition.(BM).(B, 100%)]\n A3 --> A9[R41: After organ transplantation, an early oral or enteral nutrition should be provided within 24 hours according to individual tolerance.(BM).(B, 100%)]\n A3 --> A10[R42: After small bowel transplantation, oral or enteral nutrition can be started early, with cautious increases within the first week, and then gradually increased as tolerated.(BM).(0, 100%)]\n A3 --> A11[R43: If enteral nutrition is inadequate before or after organ transplantation, supplemental parenteral nutrition should be provided.(BM).(B, 96%)]\n A3 --> A12[R44: As part of the follow-up after organ transplantation, the nutritional status should be regularly monitored. Nutritional counseling should be offered for these patients.(GPP, 96%)]\n A4 --> A13[R35: Early oral diet shall be resumed after bariatric surgery(as part of an Enhanced Recovery After Bariatric Surgery(ERABs) protocol)(BM, IE).(A, 100%)]\n A4 --> A14[R36: The use of a nasojejunal tube or jejunostomy may be considered in patients with bariatric surgery and complications with an indication for relaparoscopy/laparotomy.(GPP, 92%)]\n](1/parseimages/figure187c59a5f3df446fbf4b1f1d90800e4a_0_2.png)

Recommendation 5

The oral diet should be adapted to the type of surgical procedure and individual tolerance. Tolerance of early oral nutrition shall be assessed carefully in patients after operations with a high risk for delayed gastric emptying or postoperative ileus (BM, QL).

Grade of recommendation GPP – strong consensus 93 % agreement

Comment

The amount of oral food intake should be adjusted according to the patient's gastrointestinal function and individual tolerance [116–118,126,162–164]. This is shown by a study of older Chinese patients who had more nausea, vomiting, gastric retention, intestinal obstruction, and a higher readmission rate in the ERAS group compared with the conventional group when oral tolerance of food was impaired [165]. Thus, a more cautious approach should be adopted, especially in older patients (>75 years old). In these patients, caution should also be advised regarding early post-operative EN therapy after resections in the upper gastrointestinal tract and pancreas [151,152,165,166]. According to the ERAS guidelines the postoperative recovery of gastrointestinal motility should not be inhibited by paralytic agents [1].

While in colorectal surgery, there is sufficient evidence to recommend early postoperative oral nutrition, data in other surgical fields also point in this direction but are less clear. Even in esophageal and pancreatic surgery, early oral nutrition does not bear more risk than EN or even PN [147,166]. Here, however, a more individualized therapeutic approach should be maintained.

5. Indication for nutritional therapy

5.1. Which nutritional diagnostics are needed to determine the indication for nutritional therapy in the surgical patient?

Recommendation 6

Nutritional status should be routinely assessed when major surgery is planned in order to guide perioperative nutritional therapy.

Grade of recommendation GPP – strong consensus 100 % agreement

Statement 1

Preoperative nutritional status, postoperative course including recovery, complications, length of hospital stay, and in-hospital oral intake define post-discharge nutritional therapy and follow-up.

Strong consensus 100 % agreement

Comment

The impact of nutritional status on postoperative morbidity and mortality has been clearly demonstrated for different diseases in both retrospective [167–170] and prospective studies [12–14,171–189], and recent meta-analyses [190,191]. Inadequate oral nutritional intake for more than 14 days is associated with increased mortality [192]. Therefore, even for patients undergoing minor surgical procedures, the nutritional status should be carefully assessed, especially in case of complicated course, and weekly follow-up is recommended [193].

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Major procedures, internationally referred to as “major surgery”, involve abdominal organ resections due to tumors or (chronic) inflammatory diseases, in which procedure-specific severe (surgical-site, infectious) complications beyond simple wound healing disorders can lead to a prolongation of LOS and increased mortality.

According to GLIM criteria [18], malnutrition was associated with postoperative complications in patients with abdominal resections in the Norwegian registry study [194]. In several studies, the prevalence of malnutrition was higher when using GLIM [195,196].

Recommendation 7

In surgical patients with cancer, body composition should be assessed (BM).

When CT software is available, it should be used as a gold standard.

Grade of recommendation B – strong consensus 100 % agreement

Comment

Malnutrition is characterized by decreased body cell mass and often co-occurs with sarcopenia (reduced muscle mass and function), particularly in patients with cancer [197]. In older adults, sarcopenia can develop independently of malnutrition [198]. The SARC-F or SARC-CalF questionnaire (Questionnaire to identify individuals at risk of sarcopenia using the components Strength, Assistance in walking, Rise from a chair, Climb stairs, Falls, eventually enhanced by Calf circumference) is recommended for sarcopenia screening, and assessment involves hand grip or chair stand tests combined with measures of muscle quantity/quality via CT, DXA, magnetic resonance imaging (MRI), or BIA [19,199]. Low scores on hand grip strength or chair rise tests may be sufficient to initiate intervention [199].

Sarcopenic obesity, where increased fat can mask muscle loss, poses an additional risk [16,200–202]. It is a strong predictor of poor outcomes after major pancreatic surgery [203] and reduced long-term survival in patients with cancer [204]. Diagnosing sarcopenic obesity requires evidence of altered muscle function and body composition with increased fat and reduced muscle mass [201]. Preoperative sarcopenia is associated with increased morbidity, major complications, and longer LOS in patients with esophageal cancer [21,205–207] and with poorer overall survival in patients with gastric cancer [208]. Specific CT scan findings can predict postoperative pancreatic fistula [209]. For patients with rectal cancer, sarcopenia is linked to higher overall morbidity and infection rates, while visceral obesity is more associated with anastomotic failure [210].

Preoperative functional decline alongside poor nutritional status impairs postoperative recovery. Sarcopenia may be a modifiable factor for preoperative intervention [211,212]. Muscle mass measurement is integrated into the GLIM criteria [18]. Utilizing existing CT scans for body composition analysis is encouraged [196,202,213], particularly analyzing the L3 level axial scan for muscle area and density [20,214]. While implementation faces workload barriers, future machine learning may help. Alternatives include BIA and anthropometric measurements [196,215-218]. Standardized phase angle measurement and hand grip strength have prognostic value for postoperative complications [204,219].

Recommendation 8

A frailty assessment should be performed in older patients undergoing major surgery since frailty is associated with poor postoperative outcomes.

Grade of recommendation GPP – strong consensus 93 % agreement

Comment

Frailty, rather than chronological age, should be the primary factor in preoperative risk stratification [220,221]. Chronological

age has been a long-standing variable in research evaluating how patients tolerate treatments and their outcomes across various medical settings, including surgery. The age of 65 years is often used to define older patients due to Medicare eligibility, but with increasing life expectancy, ages of 70 and 75 years are becoming more frequent cutoffs. Studies examining the link between age and outcomes have yielded inconsistent results under these varying age definitions.

A key limitation of using age as a study variable is its non-modifiable nature, which inherently restricts the development of actionable interventions. Consequently, many clinicians advocate that age should not be the sole determinant when making critical treatment decisions. While there is a broad consensus that frail patients are more susceptible to adverse events due to a diminished multisystem reserve capacity, the routine assessment of frailty has not been consistently implemented in various clinical studies. Nevertheless, the findings that link frailty to adverse outcomes following surgery demonstrate remarkable consistency across different tools used to measure frailty.

A Cochrane review and meta-analysis encompassing five RCTs with a total of 1316 patients aged 65 and older who were undergoing surgery indicated that preoperative and/or postoperative geriatric assessment when compared with standard surgical care, might lead to a reduction in mortality rates (RR 0.85, 95 % CI 0.68 to 105). A more focused subgroup analysis involving 941 patients who underwent surgery for hip fracture revealed that the application of geriatric assessment was associated with a decreased discharge rate to an institutional setting (RR 0.71, 95 % CI 0.55 to 0.92) [222].

A systematic review published in 2015 aimed to determine the predictive capability of frailty assessment regarding postoperative outcomes. The authors analyzed six prospective studies that included 1019 patients undergoing various elective oncologic surgical procedures and evaluated the utility of geriatric assessment in predicting surgical outcomes. Their findings indicated that dependency in Instrumental Activities of Daily Living (IADLs), fatigue, and frailty were significantly associated with the occurrence of overall complications. Furthermore, dependency in IADLs was also found to be predictive of discharge to an institutional setting. Major complications were observed more frequently in patients exhibiting cognitive impairment and dependency in both IADLs and Activities of Daily Living (ADLs). Notably, the study found that age was not associated with a higher rate of complications [223].

In another study conducted from 2016 to 2019, patients aged 65 years and older with gastrointestinal cancer who were scheduled for surgical resection were randomly assigned to receive a Perioperative Enhanced Recovery for Seniors undergoing Surgery (PERI-OP) intervention (n = 82) or usual care (n = 78). Patients in the PERI-OP group had consultations with a geriatrician preoperatively in the outpatient setting and postoperatively as an inpatient consultant. In per protocol analyses, patients in the intervention group experienced shorter postoperative LOS (5.90 d vs 8.21 d, P = 0.024), and the complication rate was notably, albeit not significantly lower (6.7 % vs. 20.6 %, P = 0.137) [224].

The assessment of frailty appears to be effective not only in predicting postoperative complications but also in anticipating toxicity in frail older ads undergoing treatments for cancer. The GAP70+ trial investigated the effects of a geriatric assessment intervention on the toxic effects of cancer treatment in older patients with advanced cancer. This trial enrolled 718 patients aged 70 years and older with incurable solid tumors or lymphoma who were commencing a new treatment regimen. The geriatric assessment intervention significantly reduced the risk of severe toxicity from cancer treatment, with 50.7 % of patients in the intervention arm experiencing grade 3–5 toxicity compared with

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71.3 % in the usual care arm (RR 0.74, 95 % CI 0.64 to 0.86, P < 0.001). The intervention also demonstrated positive effects on falls and polypharmacy, with fewer falls and a greater number of medications discontinued in the intervention arm. The results suggest that geriatric assessment and geriatric assessment-guided management should be considered as the standard of care for older patients with advanced cancer and aging-related conditions [225].

While significant emphasis has been placed on the consequences of malnutrition, it is crucial to recognize that this is just one of several facets that characterize high-risk patients, such as older, frail individuals. A comprehensive assessment of frailty should include various domains, such as mobility and functional ability, cognition, the ability to succeed in daily activities, and psychosocial condition, alongside an evaluation of nutritional status.

Numerous tools have been validated for assessing frailty, with different tools focusing on specific domains of concern. Some examples of these tools, which are not exclusively limited to this list, include [221,226]:

$\bullet$ Global frailty evaluation tests: Flemish-triage risk screening tool (fTRST), geriatric 8 (G-8), Risk-analysis Index (RAI); Modified frailty index (MFI), Multidimensional prognostic index (MPI), Clinical Frailty Scale (CFS), Age-adjusted Charlson Co-morbidity Index.

$\bullet$ Mobility and functional ability: Timed up and go test, 6-min walking test, sit-to-stand test, and a question about falls over the last six months

* Cognition: Mini-Cog; Mini-Mental State Examination (MMSE)

* Ability to succeed in daily activities: Katz Activity of Daily Living (ADL), instrumental-ADL (iADL), Eastern Collaborative Oncology Group-Performance Status (ECOG-PS)

* Psycho-social condition: Distress Thermometer (DT), Geriatric Depression Scale (GDS), Geriatric Anxiety Inventory (GAI), Groningen Distress Rating Scale (GDRS); question about living situation and support

Many prospective studies have investigated the relationship between a single frailty screening tool and postoperative outcomes. While numerous tools have been identified as significant predictors of risk, it is generally recommended that tools encompassing a broader range of possible domains should be favored. These domains should be assessed for every patient and offer an ideal framework for the development of personalized rehabilitation programs based on the individual patient's specific frailty profile.

According to a survey conducted within the guideline working group, the most frequently utilized tools were:

* Global frailty evaluation: CFS (53 %), * Mobility and functional ability: Six-Minute Walking Test (71 %), * Cognition: MMSE (59 %), * Ability to perform daily activities: Katz Activity of Daily Living (ADL) (65 %), * Psychosocial condition: Tailored questions about living situation and support (44 %).

$\bullet$ Psychosocial condition: Tailored questions about living situation and support (44 %).

5.2. When is nutritional therapy indicated in the surgical patient?

Recommendation 9

In patients who are not expected to be able to take oral nutrition for five days or longer perioperatively, nutritional therapy should be started immediately with special regard to malnourished patients.

Nutritional therapy should be started immediately, also in patients who were unable to have an oral intake of more than 50 % of the recommended amount of energy for more than seven days.

Grade of recommendation GPP – strong consensus 93 % agreement

Comment

The general indication for nutritional therapy in surgery is the prevention and treatment of disease-specific malnutrition, such as compensating for a nutritional deficit before surgery and maintaining nutritional status after surgery, especially when prolonged periods of fasting and severe catabolism are anticipated. Morbidity, LOS, and mortality are the main endpoints for evaluating the benefit of nutritional therapy in the hospital.

After hospital discharge or in the setting of palliation, the primary goals of medical nutrition are to improve nutritional status and quality of life [227-238].

Enteral delivery should generally be preferred. Exceptions include:

$\bullet$ intestinal obstruction or ileus $\bullet$ peritonitis $\bullet$ suspected mesenteric ischemia $\bullet$ severe shock $\bullet$ high output intestinal fistulas

$\bullet$ severe gastrointestinal bleeding

The effect of EN on postoperative outcome has been investigated in many studies, but not homogeneously [239]. The working group reviewed 35 controlled trials with outcome endpoints [240–274]. Patients were included primarily after gastrointestinal surgery, but also after trauma or femoral neck fracture. EN was defined as the use of an oral balanced diet with supplements (ONS) and/or tube feed. Early EN was compared with a normal diet, parenteral delivery of crystalloids, and total PN. Twenty-four of the 35 studies showed significant benefits of EN in terms of a reduction in the rate of infectious complications, hospital LOS, and costs.

No benefits were observed in eight of the 35 studies longed $[240,249,253,257-259,264,268,270]$, and possible disadvantages were observed in three. The disadvantages were related to prolonged LOS [268], decreased pulmonary function after esophagectomy and pancreatic resection due to abdominal distension [272], or delayed gastric emptying after pancreatic resection resulting in prolonged LOS [273]. These problems could be a consequence of a too high EN feeding rate in the early postoperative period. In patients with severe trauma, special attention should be paid to the tolerance of the amount of EN [274]. Careful monitoring of the surgical patient in the intensive care unit (ICU) is mandatory at the beginning of EN [275]. Compared with PN, early EN decreased the postoperative infection rate in a multicentric trial including malnourished patients with gastrointestinal cancer [245].

In seven of eleven RCTS [276–286], only surrogate parameters of outcome were measured, such as the positive effects of EN on nitrogen balance and substrate tolerance. Four of the eleven studies showed no significant differences between early enteral and standard hospital nutrition [276–278,285]. The benefits of early enteral feeding within 24 h have been shown in two meta-analyses [125,128]. Focusing on patients after gastrointestinal surgery, another meta-analysis [124] of 29 studies involving 2552 patients confirmed these beneficial effects. However, no reduction in mortality could be shown.

For elective surgery, a large RCT (n = 411) showed that in postoperative patients at nutritional risk, immediate goal-directed EN was non-inferior to gradual goal-dose EN with regard to

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infectious complications. However, immediate goal-directed EN was associated with more gastrointestinal intolerance events [287].

In patients after femoral neck fracture stratified by nutritional status before randomization, nocturnal nasogastric feeding showed a significant reduction in rehabilitation time and post-operative LOS in the malnourished patients [241]. In another study with tube feeding, there was no effect on in-hospital outcomes; however, six-month mortality was reduced [269]. Use of a sip feed once daily significantly improved outcomes at six months with lower complication rates and mortality [248]. Meta-analyses of RCTs have shown lower rates of postoperative complications and shorter LOS [288,289].

Recommendation 10

If energy and substrate requirements cannot be met by oral and/or tube feeding alone (<50 % of energy requirements) within three to four days, a combination of oral, enteral, and (supplementing) parenteral nutrition should be given (BM).

Grade of recommendation B – strong consensus 100 % agreement

Comment

There are still limited controlled data on combined enteral and parenteral feeding in case of insufficient oral/enteral uptake after elective surgery. One RCT after esophagectomy showed significantly improved insulin sensitivity and decreased glucose concentrations with combined feeding [290].

A meta-analysis [291] has shown no advantage for combined nutrition in terms of mortality, infection rate, LOS, and length of ventilation. Two prospective multicenter RCTs, including critically ill patients, have addressed the question of whether parenteral supplementation should be started “early” (within four days) or “late” (after seven days) in patients with ental intolerance. The results support starting early parenteral supplementation at day four at the latest in malnourished patients and those with an expected prolonged ICU stay [292–294] (see ESPEN guideline “Clinical Nutrition in Intensive Care Medicine” [295]).

A multicenter RCT that was rated low risk of bias by the working group [296], enrolled 230 patients undergoing abdominal surgery, with the aim of an increase of nutrient intake in cases of inadequate oral/enteral nutrition. This was defined as ≤30% of energy targets from EN on POD2. The effect of early parenteral (E-SPN day 3) versus late supplementation (L-SPN was compared, and the E-SPN group received a higher mean (SD) energy intake between days three and seven compared with the L-SPN group (26.5 ± 7.4 vs. 15.1 ± 4.8 kcal/kg/d; $P < 0.001$). The E-SPN group had significantly fewer nosocomial infections compared with the L-SPN group (10/115 [8.7 %] vs. 21/114 [18.4 %]; risk difference 9.7%; 95% CI 0.9 to 18.5%; $P = 0.04$). No significant differences were observed between the E-SPN group and the L-SPN group in the number of noninfectious complications, adverse events, and other secondary endpoints. A significant difference was still found in the mean number of antibiotic therapy days between the E-SPN group and the L-SPN group (6.0 ± 0.8 vs. 70 ± 11.4; MD, 10.4%; 95% CI 0.2 to 1.9.4; $P = 0.01$) [296].

An RTC enrolled 80 patients after esophageal resection, with the aim of meeting caloric needs by early parenteral supplementation of EN [297]. Individual caloric requirements were determined by indirect calorimetry. Only patients in the combined-fed group were able to maintain stable body weight (0.18 ± 3.38 kg vs. -2.15 ± 3.19 kg, P < 0.05) and fat-free mass (1.46 ± 2.97 kg vs. -2.18 ± 4.16 kg). Morbidity, LOS, and laboratory chemistry parameters were no different. However, at three months, the early parenteral supplementation group showed significantly better quality of life scores for physical function (715 ± 24.3 vs. 60.4 ± 27.4, P < 0.05) and energy/fatigue (62.9 ± 19.5 vs. 54.2 ± 23.5, P < 0.05) [297].

Several authors have pointed out possible advantages of PN when there is limited tolerance to EN due to intestinal dysfunction, especially in the early postoperative period [270], which is then also associated with lower nutrient intake. Thus, adequate nutrient intake in the presence of limited gastrointestinal tolerance may be better achieved by PN [298].

In a randomized RCT including 254 patients undergoing open pancreatoduodenectomy in the context of an ERAS program, no benefit of supplementing parenteral nutrition to early oral feeding starting on POD1 could be observed with regard to the Comprehensive Complication Index (CCI) and the 90-day morbidity [299].

The tolerance to EN may be influenced by the rate of infusion, as shown in a large RCT (n = 411) in postoperative patients at nutritional risk, where immediate goal-directed EN was non-inferior to gradual goal-dose EN with regard to infectious complications. However, immediate goal-directed EN was associated with more gastrointestinal intolerance events [287]. A multicenter RCT in patients undergoing pancreatoduodenectomy (n = 204) showed a significantly higher overall complication rate in patients with nasojanejual enteral feeding versus those with total PN. However, there was no comparison for nasojejunal versus jejunostomy feeding [300].

Recommendation 11

Parenteral nutrition should be started as soon as possible if there is a contraindication to oral and enteral nutrition (e.g., intestinal obstruction), especially in severely malnourished patients (BM).

Grade of recommendation B – strong consensus 96 % agreement

Comment

There was controversy in the past about the effects of PN compared with standard oral/enteral nutrition with regard to the prognosis of surgical patients [239,240,244,245,250,252,256,257,259,262,264,271,298,301–308]. The secondary analysis from two RCTs (n = 635) revealed that early achievement of energy target was associated with fewer nosocomial infections (46/521 [8.8 %] vs. 21/114 [18.4%]; risk difference, 9.6 %; 95 % CI, 2.1 to 17.1 %; P = 0.004] and improved clinical outcomes (number of infectious complications and nutritional status), regardless of the nutritional strategy (early EN alone or combined with early supplemental PN) [309]. Another secondary analysis from two RCTs from the same group including 314 patients showed that early EN compared with isoenergetic SPN may not be associated with a reduced rate of nosocomial infection in patients undergoing major abdominal surgery, but may be associated with improved concentrations of serum albumin, prealbumin, and retinol-binding protein [310].

The 2009 ESPEN guidelines on parenteral nutrition in surgical patients recommend PN in the following cases [311]: malnourished patients in whom oral nutrition or EN is not feasible or not tolerated, and in patients who are incapable of ingesting and absorbing adequate amounts of nutrients for a period of at least 5–7 days due to preoperative obstruction or postoperative complications caused by limitation of gastrointestinal function [311]. This is especially true for patients with intestinal failure (e.g., short bowel <60 cm or peritoneal carcinomatosis).

The ASPEN guidelines recommend postoperative PN for patients who cannot meet their energy needs orally for 7–10 days [312].

A meta-analysis of 29 RCTs with 2552 patients after gastrointestinal surgery showed favorable effects of EN with lower rates of infectious complications, however anastomotic insufficiencies, and shorter LOS [124]. A meta-analysis including 18 RCTs with 2540 patients found, for the comparison EN versus PN, earlier onset of flatus, shorter LOS, and a higher increase in serum albumin concentration in the EN group [313]. There was no impact on mortality. Similarly, a large multicenter RCT that compared EN and PN in 2388

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patients in the ICU found no difference in mortality, rate of infectious complications, and LOS between the two groups [314].

Recommendation 12

If implantation of a central venous catheter is required solely to provide parenteral nutrition, this indication shall be made critically with respect to the anticipated duration of nutrition (BM).

Grade of recommendation A – strong consensus 93 % agreement

Comment

The placement of a central venous line may be associated with severe complications. According to a systematic review and meta-analysis of 130 studies, placement failure occurred at 20.4 (95% credible interval (Crl), 10.9 to 34.4) events per 1000 catheters placed. Other rates of central venous catheter (CVC) placement complications (per 1000 catheters) were arterial cannulation (2.8, 95% Crl 0.1 to 10), arterial puncture (16.2, 95% Crl 11.5 to 22), and pneumothorax (4.4, 95% Crl 2.7 to 6.5). Rates of CVC use complications (per 1000 catheter-days) were malfunction (5.5, 95% Crl 0.6 to 38), infection (4.8, 95% Crl 3.4 to 6.6), and deep vein thrombosis (2.7, 95% Crl 1.0 to 6.2). It was estimated that 30.2 (95% Crl 21.8 to 43.0) in 1000 patients with a CVC for three days would develop one or more serious complications (arterial canulation, pneumothorax, infection, or deep vein thrombosis. Thus, due to these risks, the indication for central PN solely should be very critical and limited to the anticipated duration of at least 15 or more days [315].

Recommendation 13

If the expected duration of supplementary PN is below seven days, nutrition can be delivered parenterally via peripheral access (BM).

Grade of recommendation 0 – strong consensus 100 % agreement

Comment

In an RCT (n = 158) of peripheral PN after colorectal resection in an ERAS program, supplementation (one day before and three days after surgery) was shown to be protective in preventing complications in those patients with decreased compliance i.e. delay in oral diet build-up and mobilization (moderate risk of bias) [316]. In the post-hoc subgroup analysis, patients with low skeletal muscle index (SMI) or BMI ≥35 kg/m$^{2}$ particularly benefited, with a significant reduction in postoperative complications [317].

An European expert group has recommended the implementation of peripheral PN, which has been little used to date, in ERAS protocols for major gastrointestinal surgery [318]. In an European survey, the use of peripheral PN was endorsed by 71 % of the surgeons surveyed as a less invasive and underutilized route for PN [319]. It is the opinion of the working group that if there is available central venous line, it should also be used for PN if indicated. The aim of PN is to help meet nutritional requirements.

A very recent randomized RCT including 254 patients undergoing open pancreatoduodenectomy in the context of an ERAS program did not show any benefit of supplementing peripheral parental nutrition to early oral feeding starting on POD1 with regard to the CCI and the 90-day morbidity [299].

Recommendation 14

For parenteral nutrition, all-in-one (three-chamber, compounded) bags should be preferred to single components (multiple-bottle systems) (BM, HE).

Grade of recommendation B – strong consensus 100 % agreement

Comment

In three RCTs, the safety and cost-benefit advantages of a three-chamber bag (all-in-one) over a multiple-bottle system/com-pounded mono-bag have been demonstrated [320–322]. In the

retrospective analysis of a large US database [323], significantly fewer sepsis episodes have been demonstrated with the use of a three-chamber bag.

5.3. Is there an indication for supplementation with glutamine?

Recommendation 15

Parenteral glutamine supplementation cannot be recommended in patients who can receive adequate oral and enteral nutrition (BM, HE).

Grade of recommendation 0 – strong consensus 93 % agreement

Recommendation 16

Patients with severe hepatic, renal, or multiorgan failure shall not receive parenteral glutamine supplementation (BM, HE).

Grade of recommendation A – strong consensus 100 % agreement

Recommendation 17

Additional enteral glutamine shall generally not be given (BM, HE).

Grade of recommendation A – strong consensus 100 % agreement

Comment on recommendations 15-17

The benefit of glutamine supplementation has been widely discussed in recent years after no benefit of supplementation or high-dose pharmacotherapy was demonstrated in general ICU patients [324-329]. A distinction must be made between a complementary strategy, as recommended and necessary in all guidelines to complete a pure PN solution, and supplementation, which involves administration of high doses beyond the essential requirement, as was done, for example, in the REDOX study enterally and parenterally [324]. In this multicenter RCT, high-dose enteral or parenteral glutamine administration showed a significant increase in mortality in critically ill patients with organ dysfunction [324], raising equal concerns about its use in surgical patients.

While smaller studies in patients with severe trauma or burns [330–333] had demonstrated clinical benefits of glutamine-enriched EN, no difference in time to discharge alive from the hospital and mortality was observed in a large-scale multicenter study (n = 1209) [334].

A number of older studies and subsequent meta-analyses have demonstrated significant benefits, such as shortened post-operative LOS and reduced number of postoperative complications after glutamine supplementation [335]. Similarly, two older meta-analyses (including 14 RCTs involving 587 surgical patients) demonstrated significant after glutamine supplementation in terms of infectious complications and hospital LOS [336,337]. In addition, a 2015 meta-analysis showed an improvement in immune response in the postoperative course in 13 RCTs that included 1034 surgical patients with gastrointestinal tumors [338]. Another meta-analysis included 19 RCTs with 1243 patients and found a significant reduction in LOS, with no differences in complication rates [339]. A recent meta-analysis included 31 studies with 2201 patients undergoing colorectal cancer surgery. Glutamine was administered parenterally in 23 studies and enterally in eight. A significant improvement was found in the glutamine group for immune function, the rates of wound complications (Z = 3.18, P = 0.001, RR 0.48, 95 % CI 0.30 to 0.75, P$^{2}$ = 0 %), the rate of anastomotic leakage (Z = 2.98, P = 0.003, RR 0.23, 95 % CI 0.09 to 0.61, P$^{2}$ = 0 %), and LOS (Z = 4.03, P = 0.000, SMD = -1.13, 95 % CI -1.68 to -0.58, P$^{2}$ = 85.6 %) [340].

However, from a methodological point, all these meta-analyses and included studies reveal significant weaknesses, such as the

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lack of clear criteria for defining infectious complications and heterogeneity in hospital LOS.

A 2014 RCT in 60 patients undergoing colon resection showed significant beneficial effects of preoperative and postoperative glutamine infusion with respect to perioperative glucose-insulin homeostasis and recovery of bowel function [341]. In contrast, a large multicenter RCT of normally nourished patients undergoing major gastrointestinal surgery failed to demonstrate any significant benefit of preoperative and postoperative parenteral administration of 0.4 g dipeptide/kg/d with regard to the development of postoperative complications or LOS [342].

In a multicenter, double-blind study of 150 surgical intensive care patients, the safety and effect of parenteral glutamine administration at the standard dose of 0.5 g/kg/d was investigated. This showed no safety risks, but also no significant differences regarding the primary endpoints of in-hospital mortality and infection rate. The 6-month cumulative mortality was 31.4 % in the parenteral glutamine group and 29.7 % in the standard parenteral group ($P = 0.88$). Despite all the positive results for glutamine supplementation, this study, rated as having low risk of bias by the working group, did not show any difference in outcomes [343]. This was a reason to downgrade the recommendation.

In conclusion, based on available data, glutamine administration at a standard dose is safe in patients without organ dysfunction. However, it has to be emphasized that most of the studies were performed with exclusive PN for 5-7 days, which cannot be recommended anymore according to ERAS, especially after elective colorectal surgery with an uncomplicated course [129,131,344]. Only expert recommendations can be made for additional administration in (sub)total PN. Based on current data, enteral pharmacotherapy by means of supplemental glutamine should not be performed, and similarly, no general recommendation can be made for supplementation of parenteral glutamine in surgical patients. For those severely malnourished patients who cannot be adequately fed by the oral and enteral route, parenteral glutamine supplementation may be considered.

Statement 2

At present, no general recommendation can be made for or against oral supplementation with glutamine. (BM)

Consensus 87 % agreement

Comment

Currently, limited evidence exists for the potential effects of oral supplementation with glutamine as a single substance. In patients undergoing pancreatic surgery, oral conditioning with glutamine, antioxidants, and green tea extract significantly increased plasma vitamin C concentrations compared with placebo, thus improving overall endogenous antioxidant capacity, but without significantly reducing oxidative stress and inflammatory response [345].

While in burn patients, a Cochrane analysis of 16 trials with 678 patients for primarily glutamine oral/enteral immunonutrition had shown a reduction in LOS (-6.55, 95 % CI -8.09 to -3.22, $I^2$ = 29.5 %) and even mortality (RR 0.25, 95 % CI 0.80 to 0.78, $I^2$ not applicable) [346], a more recent multicenter RCT with a low risk of bias including 1200 patients did not confirm these results: The median time to discharge alive from the hospital was 40 days (IQR 24-87) in the glutamine group and 38 days (IQR 22-75) in the placebo group (subdistribution hazard ratio for discharge alive of 0.91, 95 % CI 0.80 to 1.04, P = 0.17). Mortality at six months was 17.2 % in the glutamine group and 16.2 % in the placebo group (hazard ratio for death 1.06, 95 % CI 0.80 to 1.41) [334]. Overall, evidence for clinical benefit is lacking to date.

Statement 3

At present, no recommendation can be made regarding intravenous or enteral supplementation of arginine as a single substance.

Strong consensus 92 % agreement

Comment

The data on arginine supplementation as a single substance are severely limited and, in the opinion of the working group, do not permit a recommendation.

In a small RCT (n = 19) in patients after curative total gastretomy, arginine-enriched EN (10.1 g/d) in comparison with PN did not show improved body-weight loss but only a positive nitrogen balance on POD7 [347].

A meta-analysis of six studies and 397 patients who underwent surgery for head and neck cancer and received peri- or only postoperative enteral supplementation with arginine in various doses (sometimes in combination with other substances) showed a reduction in fistula formation and shortening of LOS. No significant differences were demonstrated regarding the development of wound infections, and no reduction in infectious complications was observed [348].

Data from a long-term follow-up over ten years in 32 patients with head and neck cancer who received an arginine-enriched diet perioperatively showed significantly longer survival and fewer tumor recurrences. Critically, this study was not statistically powered for survival benefit [349].

A recent secondary analysis [350] of a previous RCT [351] in patients undergoing major surgery for esophageal and pancreatic cancer failed to confirm the effects of arginine-enriched nutrition on long-term survival.

5.4. Is there an indication for parenteral supplementation with omega-3 fatty acids?

Recommendation 18

Postoperative parenteral nutrition, including omega-3 fatty acids, should be used in patients who cannot receive adequate enteral nutrition and, therefore, require predominantly parenteral or combined enteral/parenteral nutrition (BM, HE).

Grade of recommendation B – strong consensus 100 % agreement

Comment

Patients after surgical interventions regularly show a periop-erative inflammatory reaction, so the use of anti-inflammatory and immunomodulatory substances such as fish oil solutions appears promising to counteract the development of organ dysfunction and complications. A systematic review and meta-analysis of ten studies regarding anti-inflammatory and immunomodulatory ef-fects of omega-3-fatty acids supplemented lipid emulsions showed significantly decreased IL-6, CRP, and anti-tumor necrosis factor alpha (TNFα) concentrations in surgical patients with gastrointestinal carcinoma. This meta-analysis also showed a reduced LOS (P = 0.007), although no differences in postoperative infections were identified [352].

There is expert consensus that the use of omega-3 poly-unsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA), and docosexahexoic acid (DHA) found in fish oil exhibits potent anti-inflammatory properties. Fish oil seems to play a role in resolving inflammation, preserving muscle mass, and protecting liver function because of the lower phytosterol content compared with soybean oil-based formulations. This is especially true in patients with an excessive inflammatory response and postoperative indication for PN or combined EN/PN [353].

Most RCTs on different lipid emulsions for PN were conducted before 2020 and several meta-analyses have summarized these findings [316,352,354–362].

For surgical patients a meta-analysis of 19 studies omega-3 fatty acids supplemented PN found reduced infectious morbidity (OR 0.44, 95 % CI 0.30 to 0.65, P < 0.0001, I$^{2}$ = 0 %) and a significant

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reduction in LOS (weighted mean difference, -2.70 d, 95% CI -3.60 to -1.79 d, P < 0.00001, I$^{2}$ 0 %) [354].

For hospitalized patients, another meta-analysis (AMSTAR II 12/16) of 24 RCTs included 2154 hospitalized patients. In comparison with standard solutions without fish oil, fish oil enriched lipid emulsions reduced the risk of infections (RR 0.60, 95 % CI 0.49 to 0.72, P < 0.00001, P$^{2}$ = 0 %), and consecutively the LOS in intensive care (–1.95 d, 95 % CI – 3.49 to –0.42, P = 0.01, P$^{2}$ = 83 %) and in hospital (–2.14 d, 95 % CI – 2.93 to –1.36, P < 0.00001, P$^{2}$ = 51 %). The risk of sepsis (nine RCTs) was reduced by 56 % (RR 0.44, 95 % CI 0.28 to 0.70, P = 0.0004). The reduction in 30-day mortality was not significant (RR 0.84, 95 % CI 0.65 to 1.07, P = 0.15, P = 0.2 %) [361].

A meta-analysis of six RCTs evaluated potential differences between different lipid emulsions containing soybean oil, medium-chain triglycerides (MCT), olive oil, and fish oil compared with olive oil- and MCT- and long-chain triglyceride (LCT)-based emulsions [357]. No significant differences with special regard to adverse events were observed.

Another systematic review and network meta-analysis included 47 studies investigating parenteral nutrition with fish oil-containing liquid emulsions published from 2001 to 2021. Third-generation lipid emulsions containing fish oil showed a lower risk of infection compared with soybean lipid emulsions (OR 0.43, 90 % CR 0.29 to 0.63), MCT/soybean oil emulsions (OR 0.59, 90 % CR 0.43 to 0.82), and olive lipid emulsions (OR 0.56, 90 % CR 0.33 to 0.91), lower risk of sepsis when compared with soybean oil lipid emulsions, and reduced ICU LOS when compared with soybean (and MCT/soybean lipid emulsions [362].

It has to be emphasized that most of the studies were performed with exclusive PN for 5–7 days which cannot be recommended anymore according to ERAS protocols especially after elective colorectal surgery with an uncomplicated course [131,134,344], Although there is evidence supporting the benefits of fish oil lipid emulsions in surgical patients, data on their integration into ERAS protocols remain limited.

In an RCT with moderate risk of bias, olive oil-containing peripheral PN was compared with standard intravenous fluid therapy in patients one day before and three days after colorectal re- sections as part of an ERAS program [316]. Multivariable analysis of this study showed a protective effect against the incidence of postoperative complications.

So far, there are limited data comparing olive and fish oil use in surgical patients. The secondary analysis of a small RCT in critically ill patients after abdominal surgery supplemented with olive oil-based (n = 29) or a mixed-lipid emulsion (soybean oil, medium chain triglycerides, olive oil, and fish oil, SOMF, n = 25) showed no difference in clinical parameters and outcomes (serum concentrations of prealbumin, transferrin, triglycerides, cholesterol, apolipoprotein A1, and apolipoprotein B, SOFA score), oxidative stress (15-F2-tis-oprostane), and inflammatory markers (IL-1β and IL-6) [363].

In conclusion, repeatedly demonstrated positive effects for omega-3 fatty acids supplemented lipid emulsions, such as reduction of infectious complications, shorter LOS in ICU and hospital, support their use, especially in surgical ICU patients with the indication for (sub-) total PN [316,352,354-362]. The potential benefits of short-term perioperative omega-3 fatty acid infusion and its potential conditioning effect before elective surgery need further clarification [364].

Individualized use may be facilitated in the future by using artificial intelligence, including biomarkers of omega-3 derivatives, inflammatory-resolving processes, and/or muscle protein breakdown [365].

5.5. Is there an indication for a specific oral/enteral formula fortified with different immunologically active nutrient combinations (immunonutrition)?

Recommendation 19

Patients undergoing major tumor surgery should be offered immunonutrition (fortified with arginine, omega-3 fatty acids, and nucleotides) preoperatively or perioperatively (BM, HE).

Grade of recommendation B – strong consensus 93 % agreement

Comment

The rationale for perioperative oral and enteral immunonutrition is conditioning, downregulation of inflammation, and enhancement of the immune functions in order to reduce the risk of complications. It has also been called pharmaconomtrution for the intended pharmacological effects [366,367].

A large number of studies in general surgical patients have investigated the effect of immunomodulating substrates such as arginine, omega-3 fatty acids, and ribonucleotides with or without glutamine as part of nutritional supplements [368–379].

The results of the RCTs and meta-analyses (in March 2025 PubMed listed 55 meta-analyses) suggest that perioperative administration of immunomodulating substances contributes to a reduction in postoperative complications and consequently to a reduced LOS [368–428]. In terms of immunomodulating substrates, most RCTs have been conducted with arginine, omega-3 fatty acids, and nucleotides.

An umbrella review included 20 meta-analyses on different types of abdominal surgery. Overall, taking into account considerable heterogeneity, immunonutrition was associated with significantly lower rates of infectious complications (OR 0.60, 95 % CI 0.54 to 0.65, $I^2 = 64\%$) and lower postoperative morbidity (OR 0.78, 95 % CI 0.74 to 0.81, $I^2 = 30.3\%$). The exclusion of three studies with substantial heterogeneity did not change the results. Surprisingly, there was no significant difference in the timing of the intervention (pre-, peri-, or postoperative only) [429].

Regarding the timing of immunonutrition, it has been demonstrated that preoperative administration of oral immunohution for 5-7 days (arginine, omega-3 fatty acids, and ribonucleotides) can reduce postoperative morbidity and hospital LOS after major abdominal tumor surgery [395–398,401–404]. Three RCTS showed that exclusive postoperative administration of immunomodulating tube feedings was effective in both malnourished [400] and normally nourished patients with gastrointestinal tumors [396,398] and contributed to a reduction in postoperative complications in malnourished patients [401]. For a combined peri- and only postoperative use of immunomodulating diets, significant benefits in terms of the development of infectious complications and hospital LOS were demonstrated in three meta-analyses [388,393,394]. Only for postoperative use, a meta-analysis of 19 RCTs involving 2016 patients undergoing esophagectomy, gastrectomy, and pancreatectomy demonstrated a significant clinical benefit regarding a reduction in wound infections and hospital LOS [395].

A Cochrane meta-analysis on the preoperative administration of immunomodulating diets for patients undergoing gastrointesinal surgery had demonstrated significant advantages with regard to postoperative complications [410]. The recent update, including seven studies (925 patients), revealed low-certainty evidence for a decrease in infectious complications (RR 0.74, 95 % CI 0.53 to 1.04) [430]. The selection of studies may be a matter of debate.

In many studies, immunomodulating diets were compared with a usual hospital diet. In a meta-analysis of eight studies with immunomodulating ONS (561 patients) and standard ONS (895 patients) significant positive effects were shown in the

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intervention group with a decrease in infectious complications and reduction of LOS only in comparison with a normal hospital diet, but not in comparison with standard ONS [409]. Another AMSTAR II (13/16) well-rated meta-analysis focused on the preoperative use in gastrointestinal cancer patients, including data from 16 RCTs involving 1387 surgical patients with gastrointestinal carcinoma (immunonutrition n = 715, control n = 672). Preoperative immunonutrition alone for 5-7 days significantly reduced the incidence of infectious complications (OR 0.52, 95 % CI 0.38 to 0.71, P < 0.0001, I$^{2}$ = 16 %) compared with both a normal diet and a standard isonitrogenous diet. For hospital LOS, there was a significant reduction compared with normal diet and a tendency compared with standard ONS (~1.57, d 95 % CI -2.48 to -0.66, P = 0.0007, I$^{2}$ = 34 %). No impact was observed on noninfectious complications and mortality [412].

Another meta-analysis (AMSTAR II 11/16) included 35 studies with 3692 patients with surgery for gastrointestinal carcinoma. The intervention with immunonutrition was shown to significantly reduce the incidence of complications overall (RR 0.79, 95 % CI 0.70 to 0.88, P < 0.001, P$^{2}$ = 2 %), infectious complications (RR 0.66, 95 % CI 0.55 to 0.78, P < 0.001, P$^{2}$ = 45 %), and LOS [414].

Two more recent meta-analyses are available. One [431] included 37 studies with 3793 patients (22 preoperative, eleven perioperative, and nine postoperative, four trials with multiple protocols) (AMSTAR II rated 11/16). The main outcome of postoperative infectious complications was reduced with immunobrution (OR 0.58, 95 % CI 0.47 to 0.72). This association was significant in subgroup analysis only with preoperative and perioperative administration and in trials including upper gastrointestinal cancer, colorectal cancer, and 'mixed gastrointestinal' cancer populations. Significance was independent of nutritional status. In the pooled analysis, immunonutrition reduced surgical site infection (OR 0.65, 95 % CI 0.52 to 0.81), anastomotic leak (OR 0.67, 95 % CI 0.47 to 0.93), and LOS by -194 d (95 % CI -3 to -0.87) [431].

The other meta-analysis included 48 studies with 4825 patients: 19 studies had patients with upper gastrointestinal cancer, nine had lower, and eight had mixed cancer, whereas 12 had head and neck cancers (AMSTAR II 11/16). Immunonutrition reduced total postoperative complications (RR 0.78, 95 % CI, 0.66 to 0.93) and infectious complications (RR 0.71, 95 % CI, 0.61 to 0.82) compared with standard nutritional therapy [432].

Considering different types of tumors, for mixed abdominal cancer surgery, a meta-analysis of 61 RCTs showed a significant reduction in postoperative infectious complications, wound infections, respiratory tract infections, urinary tract infections, as well as fewer anastomotic leaks [411].

Three meta-anyses of six, seven, and ten good-quality RCTs involving 320, 604, and 1052 patients, respectively, have shown no clinical benefits of immunomodulation for patients undergoing esophageal resection [421,422,433].

A significant reduction in complication rate has been shown after gastrectomy in three meta-analyses [39,419,420]. Significant benefits were observed for preoperative administration in patients with gastrectomy regarding surgical site infections, infectious complications, LOS, and costs [380,418,434].

For patients undergoing liver resection, two meta-analyses (eight prospective RCTs with 805 patients and nine prospective RCTs with 966 patients, respectively) showed a significantly lower rate of overall complications, infectious complications, and significantly shorter hospital LOS when omega-3 fatty acid-containing diets were used [423,424]. Another meta-analysis with eleven studies and 1084 patients found a significant reduction in the rate of wound infections and hospital LOS for major liver resection [425].

In patients undergoing pancreatic resections, three meta-analyses (four RCTs with 299 patients, six RCTs with 366 patients, and ten RCTs with 574 patients) have also shown significantly lower rates of infectious complications and hospital LOS [426,427,435].

For patients undergoing colorectal resections, a large prospective cohort study with 3375 patients and propensity score matching as a control also observed a significant reduction in hospital LOS in the care setting when patients took an immunomodulating ONS three times daily for five days [436].

Minimally invasive surgery – ERAS

A recent meta-analysis of nine RCTs investigated immunonution in laparoscopic versus open colorectal surgery. The analysis included 1199 patients (592 immunonutrition group and 592 control group). Of these, 55.3 % (655/1184) had open colorectal surgery and 44.7 % (529/1184) underwent laparoscopic colorectal surgery. Immunonutrition reduced the risk of wound infection significantly in the studies with open surgery (RR 0.48, 95 % CI 0.32 to 0.72, P = 0.0005) and the studies including open and laparoscopic surgery (RR 0.33, 95 % CI 0.15 to 0.76, P = 0.008). Immunonutrition was also associated with a significantly shorter LOS in the open surgery group [437].

Only a few RCTs have evaluated the use of immunonutrition compared with a standard diet in patients with colorectal re-sections within an ERAS program. In the SONVI multicenter trial, 264 patients were randomized to receive the intervention or control seven days before and five days after surgery. A significant reduction in infectious complications was observed in the intervention group (23.8 % vs. 10.7 %, P = 0.0007). In terms of infectious complications, a significant difference was found in wound infections (16.4 % vs. 5.7 %, P = 0.0008) [438]. In another RCT including ERAS patients after colorectal surgery, no benefits were observed for the postoperative administration for five days in case of normal nutritional status [439].

Overall, a critical review of the trials in the numerous meta-analyses reveals some heterogeneity regarding the timing and duration of the intervention. This is the reason for the B recommendation for the pre- and perioperative use. More studies have to be performed in the future according to an ERAS protocol.

Modulation of the microbiota

The administration of probiotics or synbiotics (a combination of prebiotics and probiotics) to influence the microbiome with beneficial effects on the intestinal barrier and local immune defenses has been shown to reduce postoperative infection rates in several prospective randomized placebo-controlled clinical trials and meta-analyses, especially after major digestive surgery (pancreas, liver resection, liver transplantation, rectum), but also in trauma patients in intensive care [440].

A meta-analysis of 13 RCTs involving 962 patients found that probiotic and synbiotic use in elective surgical patients can lead to a significant reduction in septic complications [440]. A meta-analysis of five studies involving 281 trauma patients showed significant benefits in terms of a reduction in nosocomial infections (P = 0.02), rates of ventilator-associated pneumonia (three studies, P = 0.01), and LOS in the intensive care unit (two studies, P = 0.001). However, no difference was observed with respect to mortality, as there was high heterogeneity between studies [441]. A study of patients after neurosurgical trauma [442] showed significant benefits of tube feeding enriched with glutamine and probiotics in terms of the development of infectious complications and LOS in the ICU [442]. A meta-analysis of 34 prospective RCTs including 2723 patients and abdominal procedures (colorectal, upper gastrointestinal, hepatopancreaticobiliary, and liver transplant) confirmed good tolerance without adverse events. Perioperative administration of both probiotics and

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synbiotics reduced postoperative infectious complications compared with controls (RR 0.56, 95 % CI 0.46 to 0.69, P < 0.00001, n = 2,723, I$^{2}$ = 42 %). In this regard, synbiotics showed a greater effect than probiotics alone. Only synbiotics significantly reduced hospital LOS. There was no difference in mortality and noninfectious complications [443].

After colorectal surgery, a significant reduction in pneumonia (2.4 vs. 11.3 %, P = 0.029), in wound infections (7.1 vs. 20.0 %, P = 0.020), and in anastomotic leaks (1.2 vs. 8.8 %, P = 0.031) were demonstrated [444]. Similarly, a reduction in infections after pancreatic and hepatobiliary resections and liver transplantation was demonstrated [445–450]. In recent well-designed prospective studies mainly with lactobacilli and bifidobacteria, patients who received synbiotics until transplantation after listing for liver transplantation had significantly lower infection rates and lower bilirubin and transaminase concentrations at 30 and 90 days than the control group (4.8 % vs. 34.8 %) [451]. After liver resection for colorectal metastases, perioperative administration of probiotics also significantly reduced the rate of infectious complications and plasma endotoxin concentrations compared with controls [452]. In addition to reducing infectious complications, a shortened duration of antibiotic therapy and a reduction in the LOS were demonstrated in patients undergoing hepatobiliary surgery for bile duct cancer [445]. On the other hand, a nonrandomized study of patients after liver resection found no difference in surgical infections with the administration of Clostridium butyricum and prebiotics compared with the conventional group [453]. Since the available studies are very heterogeneously designed with respect to the onset and duration of therapy, composition of the probiotics and synbiotics, and route of administration, it is difficult to make a general recommendation, especially since increased mortality was observed in a large multicenter study of patients with severe pancreatitis [454]. However, this was the only study with detrimental side effects. This study was criticized because a very highly concentrated synbiotic combination was used for the first time in severe critical illness.

Another limiting factor is the very restricted availability of effective symbiotic preparations tested in clinical trials. The most effective type of probiotics is still unclear, and further adequately designed clinical studies in this field are urgently needed.

6. Preoperative nutrition

6.1 Which patients benefit from preoperative nutritional therapy?

Recommendation 20

Patients with severe malnutrition and/or high metabolic risk shall receive nutritional therapy preoperatively (A), even if it postpones surgery (BM).

A period of 10–14 days should be considered (B).

Grade of recommendation A/B – strong consensus 93 % agreement

Comment

Severe malnutrition represents a high global burden in cancer surgery and is an independent risk factor for 30-day mortality and surgical-site infection following elective surgery for colorectal or gastric cancer worldwide [455]. Preoperative weight loss ≥10 % has been shown to be a significant predictor of 1-year mortality independent of tumor stage, adjuvant treatment, age, and gender [212].

In malnourished patients and those with high metabolic risk benefits of preoperative nutritional therapy, aiming at a reduction of postoperative infections and complications, have been demonstrated in several RTCs [265,271,301,307,456] and supported by

four meta-analyses [430,457–459]. Here, patients were fed pre- operatively for a duration of at least seven to ten days.

Using the GLIM criteria, it has been shown that severely malnourised patients are at risk of increased morbidity [196,432,460,461]. According to the validation of GLIM criteria in surgical cancer patients, it can predict complications after surgery (OR 2.31, 95 % CI 1.67 to 3.21), especially infection-related complications (OR 2.31, 95 % CI 1.38 to 3.49) and wound-healing-related complications (OR 2.54, 95 % CI 1.38 to 4.71) [462].

High metabolic risk has been defined by the ESPEN working group in 2017 in the presence of any of the following criteria:

* Weight loss > 10–15 % within six months

$\bullet$ BMI <18.5 kg/m$^{2}$

$\bullet$ NRS $\ge$ 5 or subjective global assessment (SGA) grade C

$\bullet$ Serum albumin <30 g/L (exclusion of hepatic or renal insufficiency).

These parameters reflecting nutritional status and disease-related catablism have been validated for surgical patients. Ten percent weight loss in the preceding six months was associated with increased risk of adverse perioperative outcomes among adults undergoing gastrointestinal cancer surgery in the American College of Surgeons National Surgical Quality Improvement Program database (2005-2017) [463].

In agreement with the literature, the working group considers hypoalbuminemia as an evidence-based prognostic factor in surgical patients [27,464]. Recent data confirm the prognostic impact of serum albumin concentration for the occurrence of postoperative complications [14,27–29,31,464,465]. However, this is primarily more a matter of disease severity and disease-associated catabolism than nutritional status [466]. There is consensus that visceral proteins should not be used as markers of the nutritional status [32]. The degree of preoperative weight loss and serum albumin concentration were without significant influence on the rate of postoperative complications in a study [258] with 145 patients undergoing gastrectomy or subtotal gastric resection. Although the study was not statistically powered to address this issue, the data reveal that the number of patients with gastric cancer and critical weight loss or decreased serum albumin concentration is likely to be less than 20 %.

In patients undergoing abdominal surgery, decreased food intake in the week before hospital admission was identified as the only independent risk factor for the development of postoperative complications [467].

The duration of preoperative nutritional therapy should be planned according to metabolic risk. In 800 patients with gastric cancer and high metabolic risk according to the ESPEN definition, the comparison between adequate energy intake for at least 10 days and inadequate or no nutritional therapy showed a significantly lower incidence of surgical site infections (17.0 % vs. 45.4 %, P = 0.00069). Severe complications after Clavien-Dindo > III were not observed until after a therapy duration of 10–13 days. Multivariate analysis showed nutritional therapy as an independent factor for reduced incidence of surgical site infections (OR 0.14, 95 % CI 0.05 to 0.37, P = 0.0002) [468].

Preoperative administration for three days, continued for seven days postoperatively, of an oral supplement fortified with hydroxymethylbutyrate (1.2 g HMB), 7 g L-arginine, and 7 g L-glutamine showed no differences in the rate of wound healing as well as other complications compared with a placebo in patients undergoing open surgery for abdominal malignancy. Body composition and handgrip strength were also without difference [468,469]. Based on these data, the expert recommendation of 10-14 days is made.

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Only one RCT is available comparing PN and EN preoperatively. No clear advantage of preoperative PN could be shown [271]. A meta-analysis of RCTs [470] is in favor of PN in malnourished patients, as significantly lower mortality with a tendency toward lower infection rates was observed in the malnourished patients with PN (see also 5.1). Another meta-analysis [457] showed a beneficial effect of PN on reducing complication rates only in malnourished patients (see also 5.1). In a series of 1085 patients with nutritional risk by NRS-2002 before abdominal surgery [471], 512 had high nutritional risk. These received EN or PN for seven days preoperatively, based on the surgeon's experience, without knowledge of the nutrition screening. A difference in infection rate and hospital LOS was not found in patients with an NRS of three and four in the case of preoperative nutrition. Of 120 patients with an NRS of more than 5, those who received preoperative nutrition benefited significantly: with a lower complication rate (25.6 vs. 50.6 %, P = 0.008) and shorter LOS (13.7 ± 7.9 vs. 17.9 ± 11.3 d, P = 0.018).

In a meta-analysis of nine studies including 442 patients undergoing esophageal resection and 418 undergoing gastric resection, dietary counseling and EN in patients receiving neoadjuvant treatment showed positive effects in the patients with esophageal cancer for body weight maintenance and also a lower rate of surgical complications. However, the GRADE evidence rating for study quality was very low. Preoperative nutrition in patients with gastric cancer resulted in a reduction in surgical site infections, LOS, and costs. However, GRADE assessment was not possible here due to incomplete outcome data [418].

As part of a prehabilitation program, the duration of pre-hospital conditioning varies from two to six weeks (see recommendation 22).

Recommendation 21

Oral/enteral tube delivery shall be preferred whenever feasible over parenteral nutrition (BM, HE, QL).

Grade of recommendation A – strong consensus 100 % agreement

Comment

Based on the data presented in comments 10–14, the working group recommends that oral or tube supplementation shall be preferred whenever possible [313,472]. Even in the case of PN necessary to meet caloric needs, as in the case of stenosis in the upper gastrointestinal tract, oral caloric intake should be maintained, e.g., through ONS.

To avoid a refeeding syndrome in severe malnutrition, enteral tube feeding and PN should only be increased slowly under control of serum phosphate, potassium, and magnesium, taking into account possible need for thiamine replacement [125–129,140,142,473].

6.2. Is prehabilitation useful for elective surgical patients?

Recommendation 22

Prehabilitation shall be offered on a risk-stratified basis (BM, IE).

Grade of Recommendation A – strong consensus 93 % agreement

Comment

Surgical prehabilitation enhances functional capacity and physiological reserve to allow patients to withstand surgical stress [474]. Multimodal prehabilitation, comprising preoperative exercise, nutrition, psychological interventions, and/or respiratory therapy, has been found to improve both patient-centered and clinician-centered outcomes [475,476]. An umbrella of 55 systematic reviews identified there was moderate-certainty evidence that surgical prehabilitation improved functional recovery for

patients with cancer [475]. Likewise, a network meta-analysis of over 100 RCTs of uni- or multimodal prehabilitation prior to major surgery, identified exercise and nutrition prehabilitation alone, or in combination, reduced the odds of postoperative complications by 36–38% (n = 834 patients) and LOS by approximately one day (n = 10,060). Importantly, these results were robust to the exclusion of high-risk of bias trials [477]. Finally, a meta-analysis of 16 studies (six RCTs) of older adults with and without frailty (n = 3339) suggested that prehabilitation reduced the odds of severe complications by up to 44% in this vulnerable patient group [478].

The intensity of prehabilitation services should be risk-stratified, varying according to the severity of identified deficits. Assessment of functional, nutritional, and psychological aspects is required for appropriate risk stratification, guiding the level of support and resources required for optimal benefit [479,436]. Supervised prehabilitation delivered by a specialist team should be considered for patients with high risk of adverse surgical outcomes, which may include patients with severe malnutrition [480], older adults with an American Society of Anesthesiologists score III/IV [481], six-minute walk test <400 m [482] or preoperative anaerobic threshold ≤11.1 ml/kg/min [483] (as determined by cardiopulmonary exercise testing). Patients with low risk of adverse outcomes may benefit from "universal prehabilitation" or "surgery school" services, promoting better health-related quality of life, adherence to the ERAS pathway, and contributing to earlier discharge [484] or their readiness for discharge [485].

6.3. When is there an indication for preoperative use of ONS or enteral nutrition?

Recommendation 21

Patients who do not meet their nutritional needs from normal food should be encouraged to take oral nutritional supplements during the preoperative period, unrelated of their nutritional status.

Grade of recommendation GPP – strong consensus 100 % agreement

Comment

Regardless of nutritional status, ONS feeds have been studied preoperatively in digestive surgery patients in three major RCTs [253,267,486]. Although two trials did not show significant improvement in outcome, another found a significant reduction in minor complications. In addition, postoperative continuation of ONS was associated with less weight loss [267]. In a systematic review and meta-analysis of nine controlled trials (six nutritional intervention only, three multimodal) compiled from the perspective of preoperative prehabilitation in patients with colorectal resections, nutritional intervention with ONS and/or counselling for at least seven days was found to significantly reduce hospital LOS by two days. While nutritional prehabilitation alone did not improve recovery in terms of functionality at four and eight weeks, this was achieved by multimodal prehabilitation [289]. A special risk group is older adult patients with sarcopenia. Data are sparse with special regard to older patients. Daniels et al. included 33 studies with 3962 patients in their AMSTAR II well-rated systematic review targeting older patients with abdominal cancer surgery. Targeted preoperative nutritional therapy was shown to reduce postoperative complication rates in the meta-analysis. (Risk difference -0.18, 95 % CI -0.26 to -0.10, P < 0.001, I$^{2}$ = 0 %) [487].

It can be critically argued that most patients undergoing colorectal resection for cancer do not have a high nutritional risk with an overall low complication rate. This also explains the result of a systematic review of five RCTs involving 583 patients, in which

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preoperative intake of an ONS did not significantly reduce the complication rate [488]. Of note, in patients undergoing surgery for colorectal carcinoma, a lower rate of surgical site infections was observed, using the Buzby definition, in those patients with preoperative weight loss [486].

Since many patients do not meet their nutritional requirements orally in the last week preoperatively, the consensus in the working group is to motivate these patients to take ONS regardless of their nutritional status. Since compliance may be limited, it is reasonable to inform the patient in detail about potential advantages and benefits [489]. When encouraging the intake of a vitamin D supplement in patients undergoing orthopedic surgery, benefits for healing and reduction of the risk of reoperation were the most convincing arguments for the patients [490].

Recommendation 24

In patients with malnutrition and/or at high metabolic risk, an oral nutritional supplement shall be administered before major abdominal surgery in a quantity that matches the deficit of the patient's needs (calories, protein, micronutrients) (BM, HE).

Grade of recommendation A – strong consensus 94 % agreement

Comment

For severely malnourished (SGA C) undergoing gastrectomy, randomized perioperative administration of ONS (500 mL/d) has been shown to significantly reduce overall complication rates, especially severe complications (Clavien-Dindo > Illa) [491]. In a multicenter Australian observational study of 200 patients with upper gastrointestinal tract resections, patients with preoperative use of ONS for more than two weeks had significantly lower weight loss than those without (1.2 ± 1.8 % vs. 2.9 ± 3.4 %, P = 0.001). Among malnourished patients, taking the ONS for more than two weeks resulted in decreased LOS (regression coefficient -73, 95 % CI -14.3 to -0,3, P = 0.04). More than three dietary consultations resulted in a significantly reduced complication rate in malnourished patients (OR 0.2, 95 % CI 0.1 to 0,9, P = 0.04) [492].

It is the consensus of the working group that ONS must have a fully balanced nutrient composition that is not disease-specific, can serve as a sole source of nutrition, and must comply with the Regulations to a Food for Dietetic Purposes of the European Union (2016/128) (FSMP) [288,438].

The cost-effectiveness of ONS has been demonstrated for hospitalized surgical patients in a meta-analysis of RCTs [288]. Nevertheless, the overall data are somewhat inconsistent [288]. Regarding preoperative nutritional therapy in the recently updated Cochrane Review, including 16 RCTs, sensitivity analysis based on malnourished and weight-losing patients found that oral nutrition supplements may result in a slight reduction in infections (RR 0.58, 95 % CI 0.40 to 0.85; two RCTs, 184 participants) [430].

Recommendation 25

Patients with gastrointestinal cancer should be offered oral/enteral tube immunonutrition, including arginine, omega-3 fatty acids, and nucleotides, preoperatively for five to seven days. (BM, HE)

Grade of recommendation B – consensus 87 % agreement Comment

For immunonutrition, an AMSTAR II (13/16) well-rated meta-analysis focused on preoperative administration only in patients with gastrointestinal cancer. Available data from 16 RCTs involving 1387 surgical patients with gastrointestinal carcinoma (immunonutrition n = 715, control n = 672) were included. Preoperative immunonutrition alone for 5-7 days significantly reduced the incidence of infectious complications (OR 0.52, 95% CI 0.38 to 0.71,

$P < 0.0001$, $I^2 = 16\%$) compared with both a normal diet and a standard isonitrogenous diet. For LOS, there was a significant reduction compared with normal diet and a tendency compared with standard ONS ($-1.57$ d, 95 % CI $-2.48$ to 0.66, $P = 0.0007$, $P^2 = 34\%$). No impact was observed on noninfectious complications and mortality [412] (see also comment for recommendation 19). In another meta-analysis, Khan et al. explored the impact of immun�onitution on postoperative outcomes in patients undergoing surgery for gastrointestinal cancer. They demonstrated that postoperative infections were reduced by immunonutrition (OR 0.58, 95 % CI 0.47 to 0.72). Moreover, other postoperative complications and LOS were reduced as well [431]. Apart from patients with gastrointestinal cancer, Matsui et al. additionally included patients with head and neck cancers to their meta-analysis. In line with the above-mentioned analyses postoperative complications (RR 0.78, 95 % CI 0.66 to 0.93), especially infectious complications (RR 0.71, 95 % CI 0.61 to 0.82), were reduced in patients receiving immunotrition [432].

Recommendation 26

If clinically indicated, preoperative enteral nutrition, including the use of oral nutritional supplements, should be provided prehospital admission (BM, HE, QL).

Grade of recommendation GPP – strong consensus 100 %

Comment

Prehospital implementation of EN therapy, if necessary, with the support of a homecare service, should be aimed for both economic and infectious reasons. For the immunomodulating formula, see comment on recommendation 19.

6.4. When is there an indication for preoperative parenteral nutrition?

Recommendation 27

Only in those patients with severe malnutrition and/or at high metabolic risk in whom oral/enteral nutrition is not feasible, preoperative parenteral nutrition shall be provided (A) (BM).

A period of 10–14 days with a minimum of seven days can be recommended (GPP).

Grade of recommendation A/GPP – strong consensus 100 % agreement

Comment

Patients with severe malnutrition and/or at high metabolic risk in whom oral/enteral nutrition is not feasible are a highly selected group of surgical patients. In this group of patients, the benefits of preoperative PN with the aim of reducing postoperative complications are evidence-based [282,301,307,471]. Malnutrition with non-feasibility of oral/enteral nutrition is mostly observed in cases of upper gastrointestinal tumor stenosis or severe inflammatory bowel disease [493].

A large Cochrane analysis of preoperative PN showed a risk reduction for non-infectious complications from 45.2% to 28.9% in patients with gastrointestinal tract resections [410]. While the authors discussed a high bias in three of the included studies that were more than 20 years old, two more recent studies with positive results were not included in this meta-analysis [301,307].

If PN is administered for ten days preoperatively and continued for nine days postoperatively, a 1/3rd reduction in complication rate and even a reduction in mortality was observed [301].

Recovery of physical function and body protein can be achieved after only seven days of PN. Further significant improvement requires one more week [494,495]. Controlled studies comparing a duration of seven and 14 days are not available. Using the ESPEN definition of high metabolic risk for patients after gastrectomy, a retrospective study showed that severe complications according to

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Clavien-Dindo IIb were only reduced after 10–13 days of nutritional therapy, and continuation did not provide further benefits [468].

To date, only retrospective data are available for defining risk by CT-diagnosed sarcopenia. In a propensity score matching analysis of 166 sarcopenic gastrectomy patients each, Huang et al. observed a reduction in postoperative complications and hospital LOS with preoperative PN for 3-7 days only with concomitant hypalbuminemia (<35 g/l) [496]. In an RCT with moderate risk of bias, olive oil-containing peripheral PN was compared with normal fluid therapy in patients one day before and three days after colorectal resections as part of an ERAS program [316]. Multivariable analysis of this study showed a protective effect against the incidence of postoperative complications (OR 0.2, 95 % CI 0.08 to 0.87, P = 0.0031).

While the 2009 ASPEN guideline recommends seven days for preoperative PN [497], it is the opinion of the working group that in patients with severe malnutrition and at high metabolic risk, the expected reduction in the risk of complications justifies a preoperative stay longer than ten days. Whenever possible, e.g., in neoadjuvant therapy, prehabilitation for 4-6 weeks should be aimed for [477,479].

7. Postoperative nutrition

7.1. Which patients benefit most from early postoperative nutrition?

Recommendation 28

Enteral nutrition shall be started within 24 h in patients in whom the caloric requirements cannot be met orally, or an oral diet is not yet possible (A).

This applies in particular to:

$\bullet$ Patients in whom oral energy and protein intake is expected to be < 50 % in the next seven days (BM) (GPP) (100 % agreement)

* Patients after major head and neck surgery and upper gastrointestinal resection for tumor (BM) (B) (82 % agreement)

$\bullet$ Patients with severe trauma and/or severe traumatic brain injury (BM) (B) (78 % agreement)

$\bullet$ Patients with malnutrition at the time of surgery (BM) (GPP) (94 % agreement).

Grade of recommendation A/B/GPP – strong consensus 93 % agreement; agreement levels for the individual subgroups are shown at the end of each sentence.

Comment

In a prospective study of 50 patients undergoing major abdominal surgery, protein and energy intakes were recorded in the first week postoperatively. In the majority of patients, energy (82 %) and protein (90 %) intakes were inadequate. In addition, more Clavien-Dindo grade III complications were observed in patients who did not meet the protein target [498].

The rationale of early EN is to achieve caloric needs in high-risk patients in order to avoid any postoperative deterioration of nutritional status. According to a Cochrane meta-analysis, early EN within 24 h may lead to a reduced LOS [125]. Early EN was associated with a decrease in total complications in patients undergoing gastrointestinal resections in another meta-analysis [126].

RCTs and a meta-analysis have shown that early oral feeding can also be safely performed after gastrectomy and esophagectomy and is without risk for anastomotic healing [130,144,147,499]. An RCT in patients undergoing laryngectomy

and primary pharyngeal obstruction showed that it was also safe to start oral feeding on POD1 [500]. After gastrectomy, a nasojen-junal tube was not required for decompression, which was asso-ciated with a shorter LOS [143]. Early EN is also safe in patients with head injury and may suggest a favorable trend in survival rates and disability outcomes [501].

Nevertheless, with special regard to upper gastrointestinal surgery and total larynectomy, the tolerance to oral feeding may be limited [502]. To achieve tolerance to early oral feeding, the diet should be as low in fiber as possible, especially in the case of colonic anastomoses or ileostomy.

Patients undergoing major surgery for head and neck tumors and esophageal, gastric or pancreatic head carcinoma often have nutritional deficits preoperatively [176–178,187,188,503–505] and are at higher risk for developing septic complications [11,14,177,178,187,188,506]. Postoperatively, the oral intake is mostly prolonged by swelling or delayed gastric emptying until nutrition requirements can be met. Supplemental nutritional therapy reduces morbidity with a protective effect of PN and EN, including immunonutrition [14]. In an analysis of a large US healthcare database, only about 15 % of malnourished patients received postoperative ONS [507].

Patients suffering trauma are at high risk for developing septic complications or multiorgan failure even with normal nutritional status. Early EN has the goal of reducing septic complications [233,252] and has also resulted in a reduced rate of multiorgan failure when started within 24 h [508]. Adding arginine, omega-3 fatty acids, and nucleotides supplements to EN might be beneficial as well in trauma patients [379]. In patients with traumatic brain injury, early EN is associated with significantly fewer infections and a trend toward improved survival and functionality.

However, many of these studies have methodological weaknesses.

7.2. Which tube feeds should be used for enteral nutrition?

Recommendation 29

In enteral nutrition, a fully balanced standard polymeric formula should be administered.

Grade of recommendation GPP – strong consensus 100 % agreement

Comment

Most patients can be adequately fed with a fully balanced standard diet. Even if a jejunal tube is available, as in the case of a (fine) needle catheter jejunostomy (NCJ), the administration of a special oligopeptide diet may not be required. Enteral formula diets enriched with fiber are safe and may potentially decrease the rate of diarrhea. However, evidence for a standard recommendation is limited [509]. Individual patient tolerance and patient preference should also be considered when choosing enteral formula diets. To avoid tube occlusion due to clotting and infections, the use of home-made tube feeds is discouraged.

7.3. Which patients benefit from enteral tube feeding?

Recommendation 30

In patients with malnutrition and/or high metabolic risk, intraoperative placement of a nasojejunal tube or feeding jejunostomy should be considered, especially during esophagectomy, total gastrectomy, and pancreatoduodenectomy (BM).

Grade of recommendation B – consensus 89 % agreement

Comment

Numerous studies have demonstrated the low-risk/benefits of intraoperatively placing a feeding tube (nasojejunal tube or

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jejunostomy, e.g., needle catheter jejunostomy – NCJ) with the tip located distal to the anastomosis in upper gastrointestinal tract resections [371,510–515]. The open or laparoscopic placement of a NCJ [510,516–518] is considered low-risk when performed by experienced surgeons according to standardized techniques. Reported complication rate in the literature ranges from 1.5 % to 6% [400,510,514,519–529].

Nevertheless, harm-benefit discussion is inconsistent in the literature. Some authors consider routine placement of a jeunostomy to be redundant and overdone, with a recommendation only for high-risk patients [530-533]. In a recent single-center RCT (n = 48), no difference between nasojejunal tube and feeding jeunostomy was found, while the physical domain of quality of life was improved in nasojejunal patients at the time of discharge and the six-week follow-up [534].

A recent RCT showed the superiority of jejunal feeding maintenance over conventional early oral feeding regarding less body weight loss, higher calorie and protein intake, and less malnutrition state in esophagectomy patients [535]. In an RCT of 58 patients undergoing esophagectomy, those receiving jejunostomy feeding for up to six weeks had significantly less weight loss and higher calorie and protein intake at both 4-5 weeks and four months postoperatively, without increased complications or LOS. These findings suggest potential long-term benefits of jejunostomy feeding.

Meta-analyses comparing jejunostomy with nasojejunal tubes found that jejunostomy reduced postoperative pneumonia, shortened LOS, and prevented tube dislocation, but increased the risk of ileus [536]. Another meta-analysis reported comparable or lower postoperative complication rates in patients without jejunostomy [537]. However, nutritional status and body composition were not assessed in these studies.

In patients after esophagectomy or pancreatoduodenectomy, studies comparing nasojejinal or nasoduodenal tubes with jeunostomy found no major differences in overall complication rates [515,527]. Nasojejunal feeding was associated with fewer bowel complications but more frequent tube dislocation, while jejunostomy had more catheter-related issues [538]. Overall, both methods appear similarly safe, with specific advantages and disadvantages.

In patients undergoing pancreatoduodenectomy, early EN, particularly via percutaneous tubes, was associated with reduced infectious complications and shorter LOS compared with PN, as shown in several meta-analyses [539,540]. A meta-analysis of eight RCTs also showed that routine enteral nutrition supplemented to oral diet especially via a jeunostomy tube may improve postoperative outcomes [472].

Due to the higher dislocation risk of nasojejunal/nasoduodenal tubes, feeding jejunostomy is preferred for patients with malnutrition or high nutritional risk [530,541]. A scoring system may help predict the risk of severe surgical complications. [542]. EN may be continued after discharge.

Tolerance should be closely monitored, especially in patients with impaired gastrointestinal motility [274]. Rapid escalation can lead to intolerance or rare but serious complications such as ischemic bowel; gradual increase over 5-7 days is recommended [287]. Supplemental PN may be necessary.

Recommendation 31

For nutritional therapy in all perioperative periods, special attention should be given to prevent refeeding syndrome in patients with malnutrition and/or metabolic risk.

For these patients, standard enteral nutrition should be started at a low rate of intake (10–30 mL/h) and carefully increased only if electrolytes are stable, while also monitoring individual intestinal tolerance. Thus, the time to reach the

caloric target may vary greatly from individual to individual, increasing from day to day, and may take up to five days.

Grade of recommendation GPP – strong consensus 95 % agreement

Comment

For patients at risk of refeeding syndrome, particularly those with significant nutritional deficiencies or extended periods of fasting, the initiation of nutrition should be increased gradually. Refeeding syndrome is a potentially life-threatening condition resulting from fluid and electrolyte shifts that occur when reintroducing nutrition after a period of starvation or undernutrition. Therefore, for these high-risk patients, EN should begin at a slow rate (e.g., 10-30 mL/h) and be gradually increased over several days, monitoring for signs of intolerance. This cautious approach helps to prevent severe life-threatening conditions induced by rapid electrolyte shifts, such as hypophosphatemia, hypokalemia, hypomagnesemia, and vitamin B1 deficiency, leading to serious cardiac, respiratory, and neurological complications.

The recommendation aligns with recommendations in the NICE guidelines (2006, updated 2017) [543], ASPEN consensus recommendations on refeeding syndrome (2020) [544], and ESPEN guidelines on micronutrient supplementation [545], all of which emphasize the importance of gradual nutrition build-up and close monitoring for the prevention of refeeding syndrome. For detailed protocols to prevent and treat refeeding syndrome, the aforementioned guidelines should be reviewed.

Recommendation 32

If tube feeding is required for more than four weeks in patients with malnutrition and/or metabolic risk, such as in severe traumatic brain injury, percutaneous endoscopic gastrostomy or jejunal tube placement should be performed.

Grade of recommendation GPP – strong consensus 96 % agreement

Comment

A percutaneous endoscopic gastrostomy or jejunostomy (PEG or PEJ) should be performed in patients with an indication for prolonged EN, especially when laparotomy is not indicated, such as in severe traumatic brain injury or after neurosurgical procedures. In patients with stenosing esophageal cancer and planned neoadjuvant therapy, PEG placement should be coordinated with the surgeon beforehand. The guidelines for the placement of a PEG [546,547] recommend the placement for a feeding duration of 4-6 weeks.

7.4. Which patients benefit from enteral nutrition after hospital discharge?

Recommendation 33

Patients who require nutritional therapy perioperatively should have regular assessment of nutritional status during hospitalization with continuation post-hospital discharge, including referral for nutritional counseling and oral/tube supplementation as appropriate. (BM)

Grade of recommendation B – strong consensus 100 % agreement

Comment

After major gastrointestinal surgery or pancreatectomy, with special regard to cancer, oral intake alone may be inadequate for most patients over a prolonged period, indicating a potential risk for postoperative malnutrition [548–551]. In a prospective study of 50 patients undergoing major abdominal surgery, protein and energy intake were recorded in the first week postoperatively. In most patients, energy (82 %) and protein intake (90 %) were insufficient. In addition, more Clavien-Dindo III complications were observed in patients who did not reach the protein target

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[498]. After esophagectomy, approximately 30 % of patients are expected to lose more than 15 % of their body weight within six months [551]. A meta-analysis of 18 studies showed a post-operative weight loss of 5–12 % at six months, with more than half of the patients losing over 10 % of their body weight after twelve months [552].

A prospective cohort study showed adequate micronutrient intake following general recommendations in only 10% of patients undergoing esophagectomy (n = 96) with reconstruction with a gastric pull-up [548].

In patients with a complicated course and intensive care stay, an observational study found that post-extubation spontaneous caloric intake did not exceed 700 kcal/d (2.9 MJ/d) in these patients. This intake level is metabolically inadequate during a period when the recommended energy intake is 1.2–15 times the resting energy expenditure, emphasizing the importance of monitoring oral intake during recovery [553].

Therefore, it must be considered that these patients are still at metabolic risk after discharge, and, therefore, need follow-up assessment of nutritional status, including documentation of the amount of oral food intake.

Nutritional counseling is strongly recommended and very readily accepted by most patients. Additionally, postoperative and post-discharge administration of ONS has been studied in several RCTs [242,249,251,253,267,269]. A systematic review of 14 studies with 2480 patients showed a significant reduction in post-operative weight loss in patients receiving ONS after gastrointestinal surgery [554]. This is especially true for patients after major gastrointestinal surgery such as gastrectomy [550], older adult patients with fractures [170,185,248], but also after colorectal resections [555]. When ONS was taken, energy intake was significantly higher in the intervention group than in the control group [185,269]. However, in older patients, compliance with the intake of ONS was low, and this was independent of nutritional status. Nevertheless, energy intake was significantly higher in the intervention group than in the control group [185,269].

Possible causes for limited compliance for the intake of ONS [549,556,557] include taste, loss of appetite, bloating, decreased enteral tolerance with dumping syndrome, meteorism, and diarrea. However, the number of diet-related complaints was not shown to be an independent risk factor for the presence of sub-optimal nutritional intake [548]. In patients undergoing gastrectomy only 26.2 % consumed more than 250 mL of ONS per day in the second and 50.8 % in the fourth week [491].

In an RCT with 113 patients undergoing gastric surgery (73 distal gastrectomy, 40 total gastrectomy), adding ONS for twelve weeks after discharge was compared with a usual postoperative diet. The intake of ONS resulted in significantly less weight and muscle loss only in the patients with total gastrectomy, but was not observed in patients with subtotal resection [558].

Previous analyses demonstrated that the intake of oral elemental nutritional supplements (300 kcal (1.3 MJ)) after gastrectomy significantly reduced weight loss in patients who underwent curative distal or total gastrectomy in the short term [559] and in those who underwent total gastrectomy after one year [560]. This suggests that short-term ONS administration for ≥14 days may have long-term benefits for preventing weight loss. The one-year completion rate of adjuvant chemotherapy in patients who could tolerate ONS surpassed that of previous studies without ONS [561].

In another RCT, a significant reduction in weight loss, along with higher BMI and SMI, was observed in 353 patients with NRS ≥3 who received nutritional counseling combined with ONS after gastrectomy in the intervention group versus a control with nutritional counseling only. While there was no difference in 90-

day readmission rates, fatigue and loss of appetite were less common in the intervention group with dietary advice and ONS [562]. In the secondary analysis of this study, including 321 patients with NRS ≥3, long-term mortality and handgrip strength were significantly improved in the intervention group. The adjusted hazard ratio for mortality between the two groups was 0.69 (95 % CI 0.50 to 0.96, P = 0.026) [563].

A multicenter RCT of 1003 post-gastrectomy patients compared the effects of a 400 kcal/d (1.7 MJ) ONS on weight loss after one year with that of control patients without supplementation. Overall, weight loss was significantly lower in the intervention group after three months, though this effect leveled off over time, with no significant difference observed after one year. In the ONS group, only 50.4 % of patients consumed more than 200 kcal/d (0.8 MJ/d, mean 301 mL), but these patients had significantly lower body weight loss (8.2 ± 7.2 %) than the control group at one year (P = 0.0204) [564]. The advantages regarding weight loss were confirmed in a systematic review and meta-analysis of seven trials [565].

Patients after colorectal resections seem to benefit less. In an RCT after surgery for colorectal cancer, a three-month intervention with ONS led to significantly higher SMI (39.75 ± 5.83 vs. 38.01 ± 6.18 cm$^{2}$/m$^{2}$, P = 0.037) and lower sarcopenia prevalence (28.6 % vs. 42.1 %, P = 0.040). No significant differences were observed in weight, weight loss, BMI, serum albumin, or 90-day readmission rate. Delay, dose reduction, or termination of adjuvant chemotherapy were significantly reduced in the ONS group (21.2 % vs. 36.8 %, P = 0.024). ONS had no significant effect on QOL [566].

Recommendation 34

An intraoperatively placed jejunostomy may be temporarily left in place at the time of discharge, depending on weight progression and/or for the compliance with adjuvant chemotherapy.

Grade of recommendation GPP – strong consensus 100 % agreement

Comment

If a feeding jejunostomy has been placed during surgery, it may be beneficial to make an individualized decision about removal at the time of hospital discharge. If necessary, supplemental EN via the jejunostomy, such as 500–1000 kcal/d (2.1–4.2 MJ/d), administered overnight over an extended period, can be provided. In many cases, training of the patient and family enables care to be managed without the involvement of a home care service [567]. Two RCTs of home enteral feeding for 4–6 weeks demonstrated the safety and acceptance, showing better maintenance of body weight and muscle/fat compartments even after minimally invasive surgery [568,569].

A study randomized 58 patients after esophagectomy to early oral feeding (early group) or late oral feeding with jejunostomy feeding support (late group), with 29 in each group [535]. Jejunostomy feeding was maintained at discharge and continued up to six weeks postoperatively. The late group exhibited significantly less body weight loss at both 4–5 weeks postoperatively (8.3 % vs. 5.6 %; P = 0.002) and four months (15.0 % vs. 10.5 %; P = 0.003). The total calorie and protein intake were higher in the late group at 4–5 weeks (1800 kcal/d (7.5 MJ/d) vs. 1100 kcal/d (4.6 MJ/d), P < 0.001) and four months (1565 kcal/d (6.6 MJ/d) vs. 1200 kcal/d (5.0 MJ/d), P = 0.010). No difference was observed for complication rates and LOS [535].

In a prospective observational study, 24 patients underwent supplementing home eternal nutrition (HEN) after total gastrectomy for three months through a jejunostomy during the night: 1200 kcal/d (5.0 MJ/d). These patients were compared with those not receiving enteral supplementation. After three and six months, patients with nocturnal HEN had significantly less body weight loss (three months HEN 4.0 % vs. control 15.2 %, P < 0.0001, six months 7.7 % vs. 17.7 %, P < 0.0001). Regarding tolerance to

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adjuvant chemotherapy, patients with HEN significantly had a higher completion rate (70 % vs.29 %, P = 0.042) and longer duration of chemotherapy (458 vs.261 d, P = 0.031) [570].

Thus, although postoperative weight loss is often inevitable, HEN may help to attenuate deterioration [551,564,571,572]. This may be of special importance in older patients. Compared with a control group, significant benefits of HEN for eight weeks have been demonstrated in older patients after esophagectomy, with improvements in BMI, patient-generated subjective global assessment (PG-SGA) score, serum albumin, and immune parameters [569]. An RCT showed that post-discharge EN after upper gastrointestinal resections improved energy intake without improvement in fatigue, quality of life, or health economics [573]. It should be mentioned that in some patients potential disturbed sleep patterns and stoma-related problems have been observed with long-term living with a jejunostomy tube [574].

In a meta-analysis of nine RCTs involving 757 patients after esophagectomy, an oral diet was compared with HEN. HEN was associated with significantly increased body weight (WMD = 3 kg, 95 % CI 2.36 to 3.63, P < 0.001), BMI (WMD = 0.97 kg/m, 95 % CI 0.74 to 1.21, P < 0.001), albumin (WMD = 3.43 g/L, 95 % CI 2.35 to 4.52, P < 0.001), hemoglobin (WWD = 7.23 g/L, 95 % CI 5.87 to 8.59, P < 0.001), and total protein concentrations (WMD = 5.13 g/L, 95 % CI 3.7 to 6.56, P < 0.001). No significant differences were observed in prealbumin concentrations and gastrointestinal adverse events. Physical and role function were also significantly better in the HEN group. Nausea/vomiting and fatigue symptoms were significantly reduced. Appetite loss, diarrhea, and sleep disturbance in the HEN group were also significantly less than in the control group [572].

Another meta-analysis of 15 RCTs involving 1059 patients undergoing upper gastrointestinal tract resections additionally compared HEN and ONS [575]. HEN seemed to be superior because significant reduction of weight loss (-3.95 vs. -5.82 kg; SMD = 1.98 kg; 95% CI 1.24 to 2.73) and reduction of the incidence of malnutrition or latent malnutrition (RR 0.54, P < 0.01). Furthermore, improved concentrations of albumin, hemoglobin, pre-albumin, and transferrin were observed. Subgroup analysis revealed that weight loss in the HEN subgroup was significantly lower than that in the control group without any supplementation (WMD = 2.69 kg, P < 0.01). No significant difference was found between the ONS subgroup and the control group. The same results were observed for serum albumin, the physical function dimension of QL (WMD = 5.29, 95% CI 1.86 to 8.73), but the fatigue dimension of QL (WMD = -8.59; 95% CI -12.61 to -4.58) was significantly better in the HEN group [575].

Further data from controlled trials are urgently needed to assess the long-term benefits of post-hospital nutritional therapy with special regard to the comparison of enteral feeding versus oral supplementation [576].

It is the opinion of the guideline group that shared decision making after upper gastrointestinal cancer surgery should address the potential benefits of postoperative ONS and even HEN if jeunostomy is available.

For patient monitoring, self-evaluation with a validated tool such as the PG-SGA-SF can be helpful [577].

8. Bariatric surgery

Recommendation 35

Early oral diet shall be resumed after bariatric surgery (as part of an Enhanced Recovery After Bariatric Surgery (ERABS) protocol) (BM, IE).

Grade of recommendation A - strong consensus 100 % agreement

Comment

The ERABS protocol recommends reintroducing clear liquids within hours postoperatively, followed by a stepwise progression to full liquids, and then puréed or soft foods, thoroughly chewed, as tolerated [578]. Bariatric surgery guidelines recommend the implementation of ERABS and a similar stepwise reintroduction of liquids/foods [579].

The ERABS protocol reduces postoperative nausea, time to mobilization, length of ICU and hospital stays, without increasing complications or morbidity [580,581]. Observational studies suggest that introducing soft/puréed foods within one week postoperatively is safe, faster than the previous two-to-six-week guideline [582,583]. Dietitian-led counseling on food reintroduction, protein intake, and healthy eating is recommended but supported by limited evidence, with studies reporting no or mixed effects on readmissions and weight loss [578,579,584–586].

Evidence on consuming ≥60 g/d of protein remains inconsistent, with supplementation not consistently preserving fat-free mass and higher protein diets showing no clear impact on weight loss or regain [587,588].

Postoperative thiamine deficiency requires prompt treatment and is linked to factors like preexisting deficiency, rapid weight loss, poor nutrition, vomiting, diarrhea, or non-adherence to supplements [578,579]. Bariatric surgery increases the risk of multiple nutrient deficiencies, necessitating lifelong, procedure-specific supplementation and regular monitoring, although long-term adherence remains low [578,579].

Standard hypocaloric postoperative care does not require PN unless complications arise, avoiding central venous catheterization and its risks [578,579].

Recommendation 36

The use of a nasojejunal tube or jejunostomy may be considered in patients with bariatric surgery and complications with an indication for relaparoscopy/laparotomy.

Grade of recommendation GPP – strong consensus 92 % agreement

Comment

Even in cases of severe complications, the advantages of EN in terms of outcome (mortality) and cost-benefit ratio must be considered [589–591]. For EN, an intraoperatively carefully placed increased in the jotunostomy, or even gastrostomy in the residual stomach can be used [589–592]. However, the risk of leakage is increased in the patient with morbid obesity.

In a series of 126 patients undergoing revisional bariatric surgery, most feeding tubes were placed in the excluded stomach (89.7 %), and the median tube size was 18 F. Feeding tubes were used for feeding in 68.2 % of patients, with feeding initiated at a median of two days. Leakage around the tube (32.5 %) and pain (26.8 %) were common complaints. Significant tube-related complications included infection (9.1 %), dislodgement (5.9 %), reinvention (5.8 %), and reoperation (2.8 %); 16.7 % experienced at least one significant complication. Feeding tubes were removed at a median of 36 days [593].

Another series included 73 patients with leaks after sleeve gastrectomy. Feeding jejunostomy was performed in nine patients (12.3 %) complication. Patients were followed up for 12 months. All leaks heated within 8.8 ± 0.72 weeks. Patients receiving jejunal feeding had shorter recovery time (HR 2.7, P = 0.018) [594].

9. Organ transplantation

9.1. When is nutritional therapy necessary before organ transplantation?

Recommendation 37

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Recommendations for the living donor and recipient are no different from those for patients undergoing major abdominal surgery.

Grade of recommendation GPP – strong consensus 100 % agreement

Recommendation 38

In cases of malnutrition, nutritional status shall be optimized before organ transplantation (BM).

Grade of recommendation A – strong consensus 100 % agreement

Recommendation 39

In cases of malnutrition, a structured nutrition plan should be implemented first, followed by supplementation with ONS or enteral nutrition (BM).

Grade of recommendation B – strong consensus 100 % agreement

Recommendation 40

Follow-up visits of patients on the transplant waiting list should also include assessment of nutritional status.

Grade of recommendation GPP - strong consensus 100 % agreement

Comment on recommendations 37-40

Malnutrition determines the course of chronic organ failure and its prevalence in patients on the liver transplant waiting list can range from 17.2 % to 57.7 % [595]. This is particularly true for functional status (see the relevant organ-specific guidelines [596-598]). Nutritional parameters correlate with outcome after transplantation [599-603]. The often long preoperative waiting period should be used for (medical) nutritional therapy. In four interventional studies (two RCTs) on preoperative nutrition in patients on the waiting list for organ transplantation [604-607] improvement in nutritional parameters has been shown in all four studies. In the case of nutritional intervention, no relationship between mortality and nutritional status was found [595]. However, in one RCT, the improved nutritional status parameters before transplantation had no effect on outcome and mortality [605].

Initial results on the use of preoperative immunomodulating diets in patients on the liver transplant waiting list and for five days after transplantation showed favorable effects on total body protein and a possible reduction in the rate of infectious complications [607], however, this could not be confirmed in a large RCT [608].

In a recent RCT, supplementation of 3 g HMB compared with 3 g supplementation of maltodextrin (active control) with nutritional counselling for twelve weeks in 47 patients awaiting liver transplantation was investigated. Nutritional counseling with supplementation with HMB or active control improved arm circumference, dynamometry, and the frailty index in both groups. Other parameters like BMI or phase angle were without difference [609]. The secondary analysis of this RCT revealed that nutritional goals at the end of the twelve-week follow-up were only met in twelve (25.5 %) of 47 patients [610]. Another RCT including 55 patients with severe malnutrition and cirrhosis awaiting liver transplantation investigated in addition to a high-energy high protein diet nocturnal nasogastric feeding for a median duration of 63 days. The 2-fold increased energy and protein intake led to significant increase in handgrip strength, mid�-per arm circumference, triceps skin fold and immune function in the intervention group [611]. These studies demonstrate the benefits of nutritional counselling and monitoring for patients on the waiting list for organ transplantation.

No data are available on the metabolic conditioning of the living donor and recipient. Experimental results [612] showing an influence of nutritional status on liver ischemia-perfusion injury

may confirm the concept of metabolic conditioning by additional preoperative glucose drinks.

9.2. When is medical nutrition therapy indicated after organ transplantation?

Recommendation 41

After organ transplantation, an early oral or enteral nutrition should be provided within 24 h according to individual tolerance (BM).

Grade of recommendation B – strong consensus 100 % agreement

Recommendation 42

After small bowel transplantation, oral or enteral nutrition can be started early, with cautious increases within the first week, and then gradually increased as tolerated (BM).

Grade of recommendation 0 – strong consensus 100 % agreement

Comment on recommendations 41 and 42

It is generally agreed that early oral nutrition or EN is feasible and should be administered to patients undergoing organ transplantation [308,596,613]. ERAS protocols after liver transplantation, including early intake, have demonstrated benefits in reducing complications, ICU stays, hospital LOS, and mortality. However, these protocols lack standardization and relevance for long-term nutritional follow-up [614].

EN is also viable after small bowel transplantation, even with high intestinal secretions, when started at low rates in the first postoperative week [615].

Recommendation 43

If enteral nutrition is inadequate before or after organ transplantation, supplemental parenteral nutrition should be provided (BM).

Grade of recommendation B – strong consensus 96 % agreement

Comment

A meta-analysis of nine RCTs and ten cohort studies (1300 patients) reported significant benefits of EN, alone or combined with PN, over PN alone, in the form of reduced postoperative infections, ICU hours, LOS, improved nutritional status, better liver function, and fewer biliary complications after liver transplantation. The EN + PN group also had lower infection rates and higher prealbumin concentrations [616]. Early EN with PN is particularly recommended for malnourished patients [616,617]. Notably, tacrolimus absorption is unaffected by EN [618], and feeding jejunostomy is safe post-transplant [619]. If oral and tube intake are not feasible or remain inadequate, home PN is indicated [620]. Evidence for synbiotics, prebiotics, or probiotics in solid organ transplant recipients is still insufficient [621]. The use of an immunomodulating enteral diet has not shown consistent benefits [622]. For PN lipid delivery, no particular recommendations exist for patients undergoing organ transplantation.

Recommendation 44

As part of the follow-up after organ transplantation, the nutritional status should be regularly monitored. Nutritional counseling should be offered for these patients.

Grade of recommendation GPP – strong consensus 96 % agreement

Comment

Malnutrition, sarcopenia, frailty, obesity, and sarcopenic obesity are prevalent and predict poor outcomes after organ transplantation [623–626]. Energy and protein requirements are often unmet in the first month post-transplant, although energy intake increases thereafter [627]. Consequently, early post-transplant, patients lose both fat and lean body mass, with long-

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term fat mass recovery but incomplete lean mass restoration [628–631]. Sarcopenia and obesity increase over time [628,631]. Long-term nutritional follow-up and dietary counselling are, therefore, reasonable, although evidence for interventions is largely lacking. In selected cases, bariatric surgery is effective for weight loss and can be considered pre-, peri-, or post-transplantation [632,633].

10. Research questions

1. Clinical benefit of medical nutritional therapy within ERAS protocols 2. Clinical benefit of supplementation with single or combined immunomodulatory substrates, including synbiotics, in different surgical subgroups 3. Effects of modulation of the intestinal microbiota 4. Timing of initiation of supplemental parenteral nutrition 5. Importance of nutritional therapy in the post-discharge outpatient phase 6. Long-term outcomes of perioperative nutritional therapy 7. Development of new patient-centered, clinically relevant outcome parameters to evaluate the success of nutritional therapy – PROMS

Declarations

Disclaimer

This guideline has been developed with reasonable care and with the best of knowledge available to the authors at the time of preparation. They are intended to assist healthcare professionals and allied healthcare professionals as an educational tool to provide information that may support them in providing care to patients. Patients or other community members using this guideline shall do so only after consultation with a health professional and shall not mistake this guideline as professional medical advice. This guideline must not substitute seeking professional medical and health advice from a health professional.

Author contributions

Conceptualization: Arved Weimann and Stephan C. Bischoff; Data curation: N/A for a guideline: Formal analysis: All authors; Funding acquisition: No separate funding, the guideline was supported by ESPEN; Investigation: N/A for a guideline; Methodology: Arved Weimann and Stephan C. Bischoff; Project administration: Arved Weimann and Anna Schweinlin; Resources: N/A for a guideline; Software: N/A for a guideline; Supervision: N/A for a guideline; Validation: N/A for a guideline; Visualization: Anna Schweinlin and Xuan Ngoc Quynh Nguyen (ESPEN Guideline Office); Writing – original draft: All authors, in detail: Recommendation 1 MITDC, AL, HS, AW; Recommendations 2–6 MB, OL, MH, MSJ; Recommendations 7 + 8 AL, NS, AW; Recommendation 9–17 MITDC, AL, HS, AW; Recommendations 18–20 PFD, LG, JFBI, PEW; Recommendation 21 SK, TK, DNL, NS; Recommendation 22 CG, PEW, AW; Recommendations 23–26 SK, TK, DNL, NS; Recommendation 27 PFD, LG, JFBI, PEW; Recommendations 28 + 29 SK, TK, DNL, NS; Recommendations 30–34 IM, HT, OW; Recommendations 35 + 36 MB, BRR, OW; Recommendations 37–41 MITDC, DY, CLS; Recommendations 42–44 MB, BRR, OW; Writing – review and editing: AW, DNL, AS, SCB; Final approval: All authors.

No one eligible for authorship has been excluded from the list of authors.

Data sharing statement

N/a for guidelines.

Ethical approval

Not necessary.

Generative artificial intelligence and AI-assisted technologies in the writing process

None used.

Funding statement

This guideline was solely financed by ESPEN, the European Society for Clinical Nutrition and Metabolism.

Conflict of interest

The expert members of the working group were accredited by the ESPEN Guidelines Group, the ESPEN Education and Clinical Practice Committee, and the ESPEN executive. All expert members have declared their individual conflicts of interest according to the rules of the International Committee of Medical Journal Editors (ICMJE). If potential conflicts were indicated, they were reviewed by the ESPEN guideline officers and, in cases of doubts, by the ESPEN executive.

AW: grants from B. Braun and Seca. consulting fees from Lon-gevist Science for Life GmbH, payment or honoraria for lectures etc. from Abbott, Baxter Deutschland GmbH, B. Braun Melsungen AG, Falk Foundation, Fresenius Kabi Deutschlang GmbH; MB: chairman of National Society for Clinical Nutrition – Serbia (NUP-ENS); MB: payment or honoraria for lectures etc. from Health&Life Company, Honorarium for lecture on enoxaparin in high-risk pa-tients with enhanced recovery program; MITDC: grants from Abbott Nutrition, Fresenius Nutrition, Nestlé Nutrition, consulting fees from Abbott Nutrition, Fresenius Nutrition, payment or hon-oraria for lectures etc. from Abbott Nutrition, Fresenius Nutrition, Nestlé Nutrition, Resenius Kabi, Theradial, and Enteral Nutrition; PFD: consulting fees from B. Braun, Baxter, BMS, Nestlé Health Science, Nutricia, Fresenius Kabi, Theradial, Viatris; LG: payment or honoraria for lectures etc. from Baxter, support for attending meetings from Akern SpA, President of the Society ERAS-Italia; CG: payment or honoraria for lectures from Abbott Nutrition, Nestlé, Fresenius Kabi; MH: leadership or fiduciary role at the international society of pleura & peritoneum; JFBI: payment or honoraria for lectures etc. from Nestlé, Abbott, Fresenius Kabi, support for attending meetings from Nestlé, Abbott, Fortesieni Kabi; MSH: payment or honoraria for lectures etc. from Fresenius Kabi, Abbott, Baxter; SK: payment or honoraria for lectures etc. from Baxter, B. Braun, Nutricia, Fresenius Kabi, Nestlé, ESPEN chairman, Associate Editor of Clinical Nutrition; TK: nothing to declare; AL: consulting fees from Abbott, Baxter, B. Braun, Fresenius Kabi, Nestlé Health Sciences, Nutricia, payment or honoraria for lectures etc. from Abbott, B. Braun, Fresenius Kabi, Nutricia; data safety monitoring/advisory board member of Danone Oncology, Associate Editor of Clinical Nutrition; OL: payment or honoraria for lectures etc. from Encare AB, ERAS Society Executive Board, Stock owner Encare AB; DNL: Editor in Chief of Clinical Nutrition, Associate Editor of the World Journal of Surgery; CLS: payment or honoraria for lectures etc. from Abbott, Ethicon, support for attending meetings from Takeda, Chiesi; IM: payment or honoraria for lectures etc. from Olympus SE, Fresenius Kabi, International Society of Geriatric Oncology Board Member; BRR:

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Clinical Nutrition 53 (2025) 222–261

Panel Member of World Health Organisation (WHO) on Nutritional Recommendations for Hospitalised Patients in South-East Asian Region; NMS: Royalties for UpToDate; AS: nothing to declare; HS: nothing to declare; HT: nothing to declare; DLW: grants from Nestlé Health Science, Baxter, consulting fees from Sanofi, payment or honoraria for lectures etc. from Farmoquinica, Baxter, Nestlé Health Science, support for attending meetings from Sanofi, Advisory Board member of Biocodex, recipient of medical writing from Nestlé Health Science and Fresenius Kabi, Associate Editor of Clinical Nutrition; OW: payment or honoraria for lectures etc. from Fresenius Kabi, support for attending meetings from Assar Gabrielsson fond, The Local Research and Development Council Gothenburg and Södra Bohuslän, board member of SWESPEN and the Swedish Association for Clinical Nutrition (SFKN); PEW: grants from Abbott, Baxter, Fresenius Kabi, consulting fees from Abbott, Baxter, Fresenius Kabi, Nutricia, DSM, Mend Inc., ART Medical; Payment or honoraria for lectures etc. from Abbott, Baxter, Fresenius Kabi, NUC, DSM, Neste; support for attending meetings from Abbott, Baxter, Fresenius NUC, DSM, Neste; support for attending meetings from Abbott, Baxter, Fresenius, Nutricia, DSMB chair for NIH Mending trial for delirium prevention with pharmacology agent, Stock options (unvalued) in Musclesound, Unrestricted gift funding from DSM, Musclesound for research, Unrestricted education funding grant from Abbott, Associate Editor of Clinical Nutrition; DY: Principal Investigator "ONCO-Care" trial: "Malnutrition prevalence in cancer patients in Belgium" supported by Fresenius Kabi, President "Belgian Society for Surgery"; SCB: grants from Heilerde-Gesellschaft Luvos Just GmbH & Co. KG, Symbiopharm GmbH, Lactopia GmbH, payment or honoraria for lectures from Falk Foundation, Lilly, Lilly, Deprom, Bayer, Takeda, Janssen, Participation on a Data, Safety Monitoring Board or Advisory Board of Nestlé Health Science and Theralution GmbH (Medice), Associate Editor of Clinical Nutrition.

Acknowledgement

The authors thank the members of the DGEM Guideline Group for their highly valued work: Prof. Stefan Breitenstein, Winterthur/ Switzerland, Priv. Doz. Dr. Sabine Gabor, Leoben/Austria, Prof. Stefan Holland-Cunz, Basel/Bswitzerland, Prof. Matthias Kemen, Herne/Germany, Prof. Friedrich Längle, Vienna/Austria, Prof. Marc Martignoni, München/Germany, Prof. Nada Rayes, Leipzig/Germany, Prof. Bernd Reith, Kassel/Germany, Prof. Wolfgang Schwenk, Düsseldorf/Germany, Prof. Daniel Seehofer, Leipzig/Germany, Prof. Metin Senkal, Witten/Germany. Prof. Christian Stoppe, Würzburg/ Germany

The authors also thank Xuan Ngọc Quynh Nguyen for her assistance and support in this guideline project, including the creation of evidence tables, and preparational work for certainty assessment, and summary of findings tables.

Appendix A. Supplementary data

Supplementary data to this article can be found online at https://doi.org/10.1016/j.clnu.2025.08.029.

References

[1] Gustafsson UO, Scott MJ, Hubner M, Nygren J, Demartines N, Francis N, et al. Guidelines for perioperative care in elective colorectal surgery: enhanced recovery after surgery (ERAS®) society recommendations: 2018. World J Surg 2018;43:659-95. [2] Weimann A, Braga M, Carl F, Higashiguchi T, Hubner M, Klek S, et al. ESPEN guideline: clinical nutrition in surgery. Clin Nutr 2017;36:623-50. [3] Brindle ME. Why do we need guidelines and why do they fail us? Clin Nutr 2025;44:43-5. [4] Howell SJ. The need for rigour in consensus statements and guidelines. Br J Anaesth 2024;133:1123-5.

[5] Bischoff SC, Singer P, Koller M, Barazzoni R, Cederholm T, van Gossum A. Standard operating procedures for ESPEN guidelines and consensus papers. Clin Nutr 2015;34:1043-51. [6] Deferees I, Yeung JM, Arslan J, Carter VM, Isenring E, Kiss N. Adherence to ESPEN guidelines and associations with postoperative outcomes in upper gastrointestinal cancer resection: results from the multi-centre NOURISH point prevalence study. Clin Nutr ESPEN 2022;47:391-8.8 [7] Cederholm T, Barazzoni R, Austin P, Ballmer P, Biolo G, Bischoff SC, et al. ESPEN guidelines on definitions and terminology of clinical nutrition. Clin Nutr 2017;36:49-64. [8] Cederholm T, Bosaeus I, Barazzoni R, Bauer J, Van Gossum A, Klek S, et al. Diagnostic criteria for malnutrition - an ESPEN consensus statement. Clin Nutr 2015;34:335-40. [9] Soets PB, Reijven PLM, van Bokhorst-de van der Schueren MAE, Schols JMGA, Halfens RJG, Meijers JMM, et al. A rational approach to nutritional assessment, Clin Nutr 2008;27:706-16. [10] Studley HO. Percentage of weight loss. JAMA 1936;106:458-60. [11] van Bokhorst-de van der Schueren MAE, van Leeuwen PAM, Sauerwein HP, Kuik DJ, Snow GB, QC. Jag. Assessment of malnutrition parameters in head and neck cancer and their relation to postoperative complications. Head Neck 1997;19:419-25. [12] Durkin MT, Mercer KG, McNulty MF, Phipps L, Upperton J, Giles M, et al. Vascular Surgical Society of Great Britain and Ireland: contribution of malnutrition to postoperative morbidity in vascular surgical patients. Br J Surg 1999;86:702. [13] Pikul J, Sharpe MD, Lowndes R, Ghent CN. Degree of preoperative malnutrition is predictive of postoperative morbidity and mortality in liver transplant recipients. Transplantation 1994;57:469-72. [14] Bozzetti F, Gianotti L, Braga M, Di Carlo V, Mariani L, Postoperative complications in gastrointestinal cancer patients: the joint role of the nutritional status and the nutritional support. Clin Nutr 2007;26:698-709. [15] Valentini L, Volkert D, Schütz T, Ockenga J, Pirlich M, Druml W, et al. Sug- péstions for terminology in clinical nutrition. e-SPEN J 2014;9:e97-108. [16] Prado CM, Lieffers JR, McCargar LJ, Reiman T, Sawyer MB, Martin L, et al. Prevalence and clinical implications of sarcopenic obesity in patients with solid tumours of the respiratory and gastrointestinal tracts: a population-based study. Lancet Oncol 2008;9:629-35. [17] Soeters PB, Schols AM. Advances in understanding and assessing malnutrition. Curr Opin Clin Nutr Metab Care 2009;12:487-94. [18] Cederholm T, Jensen GL, Correia M, Gonzalez MC, Fukushima R, Higashiguchi T, et al. GLIM criteria for the diagnosis of malnutrition - a consensus report from the global clinical nutrition community. Clin Nutr 2019;38:1-9. [19] Barazzoni R, Jensen GL, Correia MITD, Gonzalez MC, Higashiguchi T, Shi HP, et al. Guidance for assessment of the muscle mass phenotypic criterion for the Global Leadership Initiative on Malnutrition (GLIM) diagnosis of malnutrition. Clin Nutr 2022;41:1425-33. [20] Gomez-Perez SL, Haus JM, Sheean P, Patel B, Mar W, Chaudhry V, et al. Measuring abdominal circumference and skeletal muscle from a single cross-sectional computed tomography image: a step-by-step guide for clinicians using National Institutes of Health ImageJ. JPEN - J Parenter Enter Nutr 2016;40:308-18. [21] Ishida T, Makino T, Yamasaki M, Yamashita K, Tanaka K, Saito T, et al. Quantity and quality of skeletal muscle as an important predictor of clinical outcomes in patients with esophageal cancer undergoing esophagectomy after neoadjuvant chemotherapy. Ann Surg Oncol 2021;28:7185-95. [22] Argillander TE, Spek D, van der Zaag-Loonen HJ, van Raamt AF, van Duijvendijk P, van Murster BC. Association between postoperative muscle wasting and survival in older patients undergoing surgery for non-metastatic colorectal cancer. J Geriatr Inc Ocol 2021;12:1052-8. [23] Wobith M, Lurz M, W, Beimann A. Malnutrition screening with Nutritional Risk Screening 2002 prior to assessment as part of GLIM criteria in patients undergoing major abdominal surgery for gastrointestinal cancer. Ann Nutr Metab 2024;80:268-75. [24] Gonzalez MC, Correia M, Heymsfield SB. A requiem for BMI in the clinical setting. Curr Opin Clin Nutr Metab Care 2017;20:314-21. [25] Aahlin EK, Trano G, John S, Horn A, Soreide JA, Fearon KC, et al. Risk factors, complications and survival after upper abdominal surgery: a prospective cohort study. BMC Surg 2015;15:83. [26] Khuri SF, Daley J, Henderson W, Hur K, Gibbs JO, Barbour G, et al. Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study. J Am Coll Surg 1997;185:315-27. [27] Malone DL, Genuit T, Tracy JK, Gannon C, Napolitano LM. Surgical site in-ctions: reanalysis of risk factors. J Surg Res 2002;103:89-95. [28] Suding P, Jensen E, Abramson MA, Itani K, Wilson SE. Definitive risk factors for anastomotic leaks in elective open colorectal resection. Arch Surg 2008;143:907-11. discussion 11-2. [29] Hennessey DB, Burke JP, Ni-Dhonochu T, Shields C, Winter DC, Mealy K. Preoperative hypoalbuminemia is an independent risk factor for the development of surgical site infection following gastrointestinal surgery: a multi-institutional study. Ann Surg 2010;252:325-9. [30] Hu WH, Chen HH, Lee KC, Liu L, Eisenstein S, Parry L, et al. Assessment of the addition of hypoalbuminemia to ACS-NSQIP Surgical Risk Calculator in colorectal cancer. Medicine (Baltim) 2016;95:e2999.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[31] Ying LD, Chao GF, Canner J, Graetz E, Ghiassi S, Schwartz J, et al. The degree of preoperative hypoalbuminemia is associated with risk of postoperative complications in metabolic and bariatric surgery patients. Obes Surg 2023:34:51-70. [32] Evans DC, Corkins MR, Malone A, Miller S, Mogensen KM, Guenter P, et al. The use of visceral proteins as nutrition markers: an ASPEN position paper. Nutr Clin Pract 2020; 36:22-8. [33] Wichsmeyer PE, CariI, F Evans DC, Guilbert S, Kozar R, Pryor A, et al. American Society for Enhanced Recovery and Perioperative Quality Initiative joint consensus statement on nutrition screening and therapy within a surgical enhanced recovery pathway. Anesth Analg 2018;126:1883-95. [34] Lobo DN, Gianotti L, Adiamah A, Barazzoni R, Deutz NEP, Dhatariya K, et al. Perioperative nutrition: recommendations from the ESFEN expert group. Clin Nutr 2020;39:3211-27. [35] Shimoda Y, Fujikawa H, Komori K, Watanabe H, Kano K, Yamada T, et al. Preoperative utility of the Glasgow Prognostic Score on outcomes of patients with locally advanced gastric cancer. J Gastrointest Cancer 2021:53: 265-71. [36] Van Daele E, Vanommeslaeghe H, Peirsman L, Van Nieuwenhove Y, Ceelen W, Pattyn P. Early postoperative systemic inflammatory response as predictor of anastomotic leakage after esophage�: a systematic review and meta-analysis. J Gastrointest Surg 2024;28:757-65. [37] Cederholm T, Jensen GL, Ballesteros-Pemar MD, Blaawr R, Correia M, Cuerda C, et al. Guidance for assessment of inflammation etiologic criterion for the GLIM diagnosis of malnutrition: a modified Delphi approach. Clin Nutr 2024:43:1025-32. [38] Brown RO, Alexander Jr E, Hanes SD, Wood GC, Kudsk KA, Dickerson RN. Procalcationin and enteral nutrition tolerance in critically ill patients. J P-J - Parenter Enter Nutr 2003;27:84-8. [39] Su a B, Tutone S, MacFater W, Barazanchi A, Xia W, Zeng I, et al. Diagnostic accuracy of procalciton in the early diagnosis of anastomotic leakage after colorectal after colorectal surgery: a meta-analysis. ANZ J Surg 2020;90:675-80. [40] Jerome E, McPhail MJ, Menon K. Diagnostic accuracy of procalciton and interleukin-6 for postoperative infection in major gastrointestinal surgery: a systematic review and meta-analysis. Ann R Coll Surg Engl 2022;104:561-70. [51] Bona D, Daneli P, Sozzi, A Sanzi, Marey L, Lombardo F, et al. C-reactive protein and procalcitonin levels to predict anastomotic leak after colorectal surgery: systematic review and meta-analysis. J Gastrointest Surg 2023;27:166-79. [82] Holger Schünenmann JB, Guyt G, Oxann A. GRADE Handbook. Handbook for grading the quality of evidence and the strength of recommendations using the GRADE approach. 2013. Available at: https://gurtdegrapro.org/app/handbook/handbook.html. [93] Weimann A, Breitenstein S, Gabor S, Holland-Cunz S, Kemen M, Lângle F, et al. S-Leitlinie Klinische Ernährung in der Chirurgie der Deutschen Gesellschaft für Ernährungsmedizin (DGEM) e. V. Aktuelle Ernährungsmed 2023;48:237-90. [144] Murd MH, Mustafa RA, Schüinemmann HJ, Sultan S, Santesso N. Rating the certainty in evidence in the absence of a single estimate of effect. Evid Base Med 2017:22:85-7. [15] Shea BJ, Reeves BC Wells, Th Guku M, Hamel's C, manor J, et al. Amst 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. Br Med J 2017:358:4008. [46] Higgins JP, Altman DG, Getzsche PC, Juni P, Moher D, Oxman AD, et al. The Cochrane Collaboration's tool for assessing risk of bias in randomised trials. Br Med J 2011:343:d5928. [47] Wells GA, Shea B, O'Connell D, Peterson J, Welch V, Losos M, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. 2013. Available at: https://www ohrica/na programs/clinical_epidemiology/oxford.asp. [48] The Joanna Briggs Institute Critical Appraisal tools for use in JBI Systematic Reviews. Checklist for analytical cross sectional studies. 2017. Available at: https://jbi.global/sites/default/files/2019-05/BJ-Critical_Appraisal-Ccheckist-for,Analyanical-Cross_Sectoral.Studies/2017.0.pdf. [49] Scottish Intercolerge Globalized Guidelines Network (SIGN). Sign 50: a guideline developer's handbook. Revised version. Edinburgh: SIGN: 2014. Available at: https://www sign.ac.uk/our-guidelines/sign-50-a-guideline-developen-handbook/186). Schold, http://www sign.ac.uk/our-guidelines/sign-50-a-guideline-developen-handbook/186).

gastrointestinal surgeries: a randomized clinical trial. J Caring Sci 2021;10: 177–83. [55] Xu J, Wang L, Li P, Hu Y, Wang C, Cheng B, et al. Perioperative and post-hospital whole-course nutrition management in patients with pan-creatoduodenectomy – a single-center prospective randomized controlled trial. Int J Surg 2024;1:10:4185–96. [56] Brady M, Kinn S, Stuart P. Preoperative fasting for adults to prevent peri-operative complications. Cochrane Database Syst Rev 2003;4:CD004423. [57] Lambert E, Carey S. Practice guideline recommendations on perioperative fasting: a systematic review. JPEN – J Parenter Enter Nutr 2016;40:1158–65.6. [58] Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures: a report by the American Society of Anesthesiative Task Force on Preoperative Fasting. Anesthesiology 1999;90:896-905. [59] Lobo DN, Hendry PO, Rodrigues G, Marciani L, Totman JJ, Wright JW, et al. Gastric emptying of three liquid oral preoperative metabolic pre-conditioning regimens measured by magnetic resonance imaging in healthy adult volunteers: a randomised double-blind, crossover study. Clin Nutr 2009;28:636–41. [60] Soreide E, R. Spreed J. R. New preoperative fasting guidelines in Nor-way. Acta Anaesthesio Scand 1997;41:799. [61] Spies CD, Breuer JP, Gust R, Wichmann M, Adolph M, Senkal M, et al. Pre-operative fasting. An Anaesthesist 2003;52:1039–45. [62] Ljungqvist O, Scott M, Fearon KC. Enhanced recovery after surgery: a review. JAMA Surg 2017;152:292–8. [63] Joshi GP, Abdelmakal BB, Weigel WA, Harbell MW, Kuo Cl, Soriano SG, et al. 2023 American Society of Anesthesiologists practice guidelines for pre-erative fasting: carbohydrate-containing clear liquids with or without protein, chewing gun, M-J, Lee J-R, Kim D-C. Effects of preoperative oral carbohydrate during a Internet well-being and satisfaction in thyroid surgery, Korean J Anesthesiol 2023;18:332–51. [64] Nygren J, DR H, Keungvist O. Preoperative oral carbohydrate therapy. Curr Opin Anaesthesio 2015;28:364–9. [65] Amer MA, Smith MD, Herbison GP, Plank LD, McCall JL. Network meta-analysis of the effect of preoperative carbohydrate loading on recovery af-ter elective surgery. Br J Surg 2017;104:187–97. [66] Yagci G, Cam MF, Oturk T, E dag B, Ozgurtas T, Cosar A, et al. Effects of preoperative carbohydrate loading on glucose metabolism and gastric contents in patients undergoing moderate surgery: a randomized, controlled trial. Nutrition 2008;24:212–6. [68] Tudor-Drobjewski BA, Marhofer P, Kimberger O, Huber WD, Roth G, Trifterer L. Randomised controlled trial comparing preoperative carbohydrate loading with standard fasting in paediatric anaesthesia. Br J Anaesth 2018;121:556–61. [69] Svanfeldt M, Thorell A, Hausel J, Soop M, Rooyackers O, Nygren J, et al. Randomized clinical trial of the effect of preoperative oral carbohydrate treatment on postoperative whole-body protein and glucose kinetics. Br J Surg 2007;142:50–52. [670] Svanfeldt M, Thorell A, Hausel J, Soop M, Nygren J, Ljungqvist O. Effect of preoperative oral carbohydrate treatment on insulin action–a randomised cross-over unblised study in healthy subjects. Clin Nutr 2005;24:815–21. [71] Rizvanovic N, Nesek Adam V, Causevic S, Dervisevic S, Delibegovic S. A randomised controlled study of preoperative oral carbohydrate loading versus fasting in patients undergoing colorectal surgery. Int J Colorectal Dis 2019;34:1551–61. [72] Dock-Nascimento DB, de Aguilar-Nascimento JE, Magalhaes Faria MS, Caporossi C, Shlessarko N, Waitzberg DL Evaluation of the effects of a preoperative 2-hour fast with maltodextrine and glutamine on insulin resistance, acute-phase response, nitrogen balance, and serum glutathione after laparocapico chocystectomy. JPEN – J Parenter Enter Nutr 2012;36:43–52. [73] Gutch M, Kumar S, Razi A, Assessment of insulin sensitivity/resistance. Indian J Endocrinol Metab 2015;19:160–4. [74] Mathur S, Plank LD, McCall JL, Shapkov P, Mcllroy K, Gillanders LK, et al. Randomized controlled trial of preoperative oral carbohydrate treatment in major abdominal surgery. Br J Surg 2010;97:485–94. [75] Baban B, Thorell A, Nygren J, Bratt A, Ljungqvist O. Determination of insulin resistance in surgery: the choice of method is crucial. Clin Nutr 2015;34:123–123. [76] Mizock BA. Blood glucose management during critical illness. Rev Endocr Metab Disord 2003;4:187–94. [77] Sato H, Carvalho G, Sato T, Lattermann R, Matsukawa T, Schricker T. The association of preoperative glycemic control, intraoperative insulin sensitivity, and outcomes after cardiac surgery. J Clin Endocrinol Metab 2010;95:4338–44. [78] Soop M, Nygren J, Thorell A, Weidenhielm L, Lundberg M, Hammarqvist F, et al. Preoperative oral carbohydrate treatment attenuates endogenous glucose release 3 days after surgery. Clin Nutr 2004;23:733–41. [79] Awad S, Varadhan KK, Ljungqvist O, Lobo DN. A meta-analysis of randomised controlled trials on preoperative oral carbohydrate treatment in elective surgery. Clin Nutr 2013;32:34–44.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[80] Smith MD, McCall J, Plank L, Herbison GP, Soop M, Nygren J. Preoperative carbohydrate treatment for enhancing recovery after elective surgery. Cochrane Database Syst Rev 2014;8:CD009161. [81] Noba L, Wakefield A. Are carbohydrate drinks more effective than preoperative fasting: a systematic review of randomised controlled trials. J Clin Nurs 2019;28:3096-116. [82] Noblett SE, Watson DS, Huong, H. Davison B, Hainsworth J, Horgan AF. Preoperative oral carbohydrate loading in colorectal surgery: a randomized controlled trial. Colorectal Dis 2006;8:563-9. [83] Ricci C, Ingaldi C, Alberici L, Serbassi F, Pagano N. De Raffelle E, et al. Preoperative carbohydrate loading before active abdominal surgery: a systematic review and network meta-analysis of phase II/III randomized controlled trials. Clin Nutr 2022;41:313-20. [84] Hamamoto H, Yamamoto M, Masubuchi S, Ishii M, O乡omi W, Tanaka K, et al. The impact of preoperative carbohydrate loading on intraoperative body temperature: a randomized controlled clinical trial. Surg Endosc 2018;32:4393-401. [85] Gianotti L, Biffi R, Sandini M, Marrelli D, Vignali A, Caccialanza R, et al. Preoperative oral carbohydrate load versus placebo in a effective abdominal surgery (PROCY). Ann Surg 2018;267:623-30. [86] Şavluk ÖF, Kuscia M, Güzelmeric F, Gürcü ME, Kilirin A, Gevired D, et al. Do preoperative oral carbohydrates improve postoperative outcomesin patients undergoing coronary artery bypass grafts? Turk Med Sci 2017;47:1681-6. [87] Breuer JP, von Dossow V, von Heymann C, Griesbach M, von Schickfus M, Mach E, et al. Preoperative oral carbohydrate administration to ASA IV-patients undergoing elective cardiac surgery. Anesth Analg 2006;103:1099-108. [88] Jarvela K, Maaranen P, Sisto T. Pre-operative oral carbohydrate treatment before coronary artery bypass surgery. Acta Anaesthesiol Scand 2008;52:793-7. [89] Bopp C, Hofer S, Klein A, Weigand MA, Martin E, Gust R. A liberal preoperative resting regimen improves patient comfort and satisfaction with anesthesia care in day-stay minor surgery. Minerva Anestesiol 2011;77:680-60. [90] Hause J, Nygren J, Lagerkranser M, Hellstrom PM, Hammarqvist F, Almstrom C, et al. A carbohydrate-rich drink reduces preoperative discomfort in electroive surgery patients. Anesth Analg 2001:93:1344-50. [91] Kaska M, Grosmanova T, Havel E, Hyspler R, Petrova Z, Brtkto M, et al. The impact and safety of preoperative oral or intravenous carbohydrate administration versus fasting in colorectal surgery-a randomized controlled trial. Wien Klin Wochensch 2010;122:23-30. [92] Meisner M, Ernhofer U, Schmidt J. Liberalisation of preoperative fasting guidelines: effects on patient comfort and clinical practicability during elective laparoscopic surgery of the lower abdomen. Zentralblr Chir 2008;133:479-85. [93] Onalan E, Andsoy II, Ersoy OF. The effect of preoperative oral carbohydrate administration on insulin resistance and comfort level in patients undergoing surgery. J Perianest Nurs 2019;34:539-50. [94] Rapp-Kesek D, Stridsberg M, Andersson LG, Berne C, Karlsson T. Insulin resistance after cardiopulmonary bypass in the elderly patient. Scand-Cartodovas J 2007;41:102-8. [95] Bisgaard T, Kristiansen VB, Hjortsø NC, Jacobsen LS, Rosenberg J, Kehlet H. Randomized clinical trial comparing an oral carbohydrate beverage with placebo before laparoscopic cholecystectomy. Br J Surg 2004;91:151-8. [96] Bisgaard T, Kehlet H. Letter: randomized clinical trial of the effects of oral preoperative carbohydrates on postoperative nausea and vomiting after laparoscopic cholecystectomy (Br J Surg 2005; 92: 415-421). Br J Surg 2006;93:120 [author reply]. [97] Lee JS, Song Y, Kim JV, Park J. Yoon Ds. Effects of preoperative oral carbohydrates on quality of recovery in laparoscopic cholecystectomy: a randomized, double blind, placebo-controlled trial. World J Surg 2018;42:3150-7. [98] Helminen H, Branders H, Ohtonen P, Saarnio J. Effect of preoperative oral carbohydrate loading on recovery after day-case cholecystectomy. Eur J Anaesthesiol 2019;36:605-11. [99] Cakar E, Yilmaz, Čak Ear, Bayd H. The effect of preoperative oral carbohydrate solution intake on patient day: a randomized controlled study. J PeriAnesthesia Nurs 2017;32:589-99. [99] Pochella LA, Mehran RJ, Curtin K, Schneider JM. Preoperative carbohydrate loading in patients undergoing thoric surgery: a quality-improvement project. Perianestus 2019;34:1250-6. [99] Suh S, Hetzel E, Alterroilo K, Lak K, Schneider JM. Preoperative and preoperative carbohydrate loading on postoperative cardiac treatment in a non-transmorm (Br J Surg 2005; 92: 415-421). Br J Surg 2006;93:120 [author reply]. [99] Lee JS, Song Y, Kim JV, Pao M, Hao J. Yoon Ds. Effects of preoperative oral carbohydrates on status of recovery in laparacopsic cholecystectomy: a randomized, double blind, placebo-controlled trial. World J Surg 2018;42:3150-7. [99] Helminen H, Branders H, Ohtonen P, Saarnio J. Effect of preoperative oral carbohydrate loading on recovery after day-case cholecystomy. Eur J Anaesthesiol 2019;36:605-11. [99] Cakar E, Yilmaz, & Çakar E, Bayder H. The effect of preoperative oral carbohydrate solution intake on patient day: a randomized controlled study. J PeriAnesthesia Nurs 2019;37:5289-99. [99] Pochella LA, Mehran RJ, Curtin K, Schneider JM. Preoperative carbohydrate loading in patients undergoing thoric surgery: a quality-improvement project. Perianestus 2019;34:1250-6. [99] Suh S, Hetzel E, Alterroilo K, Lak K, Schneider JM. Preoperative and preoperative carbohydrate loading on postoperative carbohydrate loading on postoperative cardiac treatment in a non-transmorm (Br J Surg 2005; 92: 415-421). Br J Surg 2006;93:120 [author reply]. [97] Lee JS, Song Y, Kim JV, Pao M, Hao J. Yoon Ds. Effects of preoperative oral carbohydrates on status of recovery in laparacops (Cholecystomy: a randomized, double blind, placebo-controlled trial. World J Surg 2018;42:3150-70. [98] Helminen H, Branders H, Ohtonen P, Saarnio J. Effect of preoperative oral carbohydrate loading on recovery after day-case chlecystomy. Eur J Anaesthesiol 2019;36:605-11. [99] Dambers H, Jerman R, Jorsan M, Vasioulos T. Impact of oral carbohydrate consumption prior to cesarean delivery on preoperative oral carbohydrate solution intake on patient day: a randomized controlled study. J PeriAnesthesia Nurs 2017;32:589-99. [99] Pochella LA, Mevan R, Curtin K, Schneider JM. Preoperative carbohydrate loading in patients undergoing thoric surgery: a quality-improvement project. Perianestus 2019;34:1250-6. [99] Pochella LA, Mevan R, Curtin K, Schneider JM. Preoperative and preoperative carbohydrate loading on postoperative carbohydrate loading on user-based therapy. J PeriAnestsus 2019;36:605-11. [99] Dambers H, Jorsan M, Vasioulos T. Impact of oral carbohydrate consumption prior to cesarean delivery on preoperative oral carbohydrate solution intake on patient day: a�odococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococ

[104] Ljungqvist O, Thorell A, Gutniak M, Häggmark T, Efendic S. Glucose infusion instead of preoperative fasting reduces postoperative insulin resistance. J Am Coll Surg 1994;178:329-36. [105] Crowe PJ, Dennison A, Royle GT. The effect of pre-operative glucose loading on postoperative nitrogen metabolism. Br J Surg 1984;71:635-7. [106] Yi HC, Ibrahim Z, Abu Zaid Z, Mat Daud ZA, Md Yusop NB, Omar J, et al. Impact of enhanced recovery after surgery with preoperative whey protein-infused carbohydrate loading and postoperative early oral feeding among surgical gynecologic cancer patients: an open-labelled randomized controlled trial. Nutrients 2020;12:264. [107] Braga M, Bissolati M, Rocchetti S, Beneduce A, Pecorelli N, Di Carlo V. Oral preoperative antioxidants in pancreatic surgery: a double-blind, randomized, clinical trial. Nutrition 2021;28:160-4. [188] Vermeulen MAR, Richar MC, Garretsen MK, van Schie A, Ghatei MA, Holst JJ, et al. Gastric emptying, glucose metabolism and gut hormones: evaluation of a common preoperative carbohydrate beverage. Nutrition 2011;27:897-903. [199] Gustafsson UO, Nygren J, Thorell A, Soop M, Hellström PM, Ljungqvist O, et al. Preoperative carbohydrate loading may be used in type 2 diabetes patients. Acta Anaesthesiol Scand 2008;52:946-51. [110] Lai Y, Cai Y, Ding Z, Zhang C, Luo Z, Zhou Z. Effect of preoperative carbohydrate loading on postoperative recovery of individuals who have type 2 diabetes after total knee arthroplasty: a randomized controlled trial. J Arthroplasty: 2025;40:665-71. [111] Vishak M, Gayathri B, Chandrasekhar G, Ramani S. Randomized controlled trial: comparing the effects of preoperative carbohydrate and non-arbohydrate loading on gastric emptying in diabetic and non-diabetic patients posted for effective surgery. Cureus 2023;15:e49213. [112] Zhao C, Shi J, Zhu N, Yang P, Xiang B, Dai Y, et al. Clinical effectiveness and prooperative. Aoral carbohydrate loading in patients with diabetes: a systematic review. Diabetes Metabol Syndr 2024;18:103140. [113] Bickel A, Shtamler B, Mizrafi S. Alyral food feeling following removal of nasogactir tube in gastrointestinal operations. A randomized prospective study. Arch Surg 1992;127:287-9. discussion 9. [114] Elmore MF, Gallagher SC, Jones JG, Koons KK, Schmalhausen AW, Strange PS. Esophagogastr decompression and enteral feeding following cholecystectomy: a controlled, randomized prospective trial. JPEN - J Parenter Enter Nutr 1989;13:377-87.1 [115] Petrelli NJ, Stulc JP, Rodriguez-Bigas M, Blumenson L. Nasogastric decompression following elective colorectal surgery: a prospective randomized study. Am Surg 1993;59:632-5. [116] Feo CV, Romaniin B, Sertini D, Ragazzi R, Zamboni P, Pansini GC et al. Early oral feeding after colorectal resection: a randomized controlled study. ANZ J Surg 2004;74:298-301. [117] Lassen K, Kjaeve J, Fetveit T, Trano G, Sigurdsson HK, Horn A, et al. Allowing normal food at after major upper gastrointestinal surgery does not increase morbidity: a randomized multicenter trial. Ann Surg 2008;247:721-9. [118] Reissman P, TeoTA, Cohen SM, Weiss EG, Nogueras JJ, Wexner SD. Is early oral feeding safe after elective colorectal surgery? A prospective randomized trial. Ann Surg 1995;222:73-7. [119] Nematihon B, Salimi S, Noorian V, Samsami M. Early versus delayed (traditional) postoperative oral feeding in patients undergoing colorectal anastomosis. Adv Biomed Res 2018;7:30. [120] Lewis SJ, Egster PA, Thomas S. Early enteral feeding versus "nil by mouth" after gastrointestinal surgery: systematic review and meta-anastomosis. Adv Biomed Res 2018;7:323-77. [121] Barlow R, Price P, Reid T, Hunt S, Clark GW, Havard TJ, et al. Prospective multicentre randomised controlled trial of early enteral nutrition for patients undergoing major upper gastrointestinal surgical resection. Clin Nutr 2011;30:560-6. [122] Wu JM, Kuo TC, Chen HA, Wu CH, Lai SR, Yang CY, et al. Randomized trial of oral versus enteral feeding for patients with postoperative pancreatic fistula after pancreatodudenectomy. Br J Surg 2019;106:190-8. [123] Smeets BJJ, Peters EG, Horsten ECJ, Weijs TJ, Rutten HJT, Buurman WA, et al. Effect of early vs late start of oral intake on anastomatic leakage following elective lower intestinal surgery: a systematic review. Nutr Clin Pract 2018;33:803-12. [124] Mazaki T, Ebisawa K. Enteral versus parenteral nutrition after gastrointesinal surgery: a systematic review and meta-analysis of randomized controlled trials in the English literature. J Gastrointest Surg 2008;12:739-55. [125] Herbert G, Perry R, Andersen HK, Atkinson C, Penfold C, Lewis SJ, et al. Early enteral nutrition within 24 hours of lower gastrointestinal surgery versus later commencement for length of hospital stay and postoperative complications. Cochrane Database Syst Rev 2019;7:CD004080. [126] Osland E, Yunus RM. Khan S, Monem MA. Early versus traditional post-operative feeding in patients undergoing resectional gastrointestinal surge: a meta-analysis. JEPEN - J Parenter Enter Nutr 2011;35:473-87. [127] Zeng S, Xue Y, Zhao J, Liu A, Zhang Z, Sun Y, et al. Total parental nutrition versus early enteral nutrition after cystectomy: a meta-analysis of post-operative outcomes. Int Urol Nephrol 2019;51:1-7. [128] Lewis J5, Asperchen HK, Thomas S. Early enteral nutrition within 24 h of intestinal surgery versus later commencement of feeding: a systematic review and meta-analysis. J Gastrointest Surg 2009;13:569.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[129] Varadhan KK, Neal KK, Dejong CH, Fearon KC, Ljungqvist O, Lobo DN. The enhanced recovery after surgery (ERAS) pathway for patients undergoing major elective open colorectal surgery: a meta-analysis of randomized controlled trials. Clin Nutr 2010:29:434-40. [130] Lassen K, Soop M, Nygren J, Cox PB, Hendry PO, Spies C, et al. Consensus review of optimal perioperative care in colorectal surgery: enhanced Recovery after surgery (ERAS) group recommendations. Arch Surg 2009:144:961-9. [131] Greco M, Capretti G, Beretta L, Gemma M, Pecorelli N, Braga M. Enhanced recovery program in colorectal surgery: a meta-analysis of randomized controlled trials. World J Surg 2014:38:1531-41. [132] Liu F, Wang W, Wang C, Peng X. Enhanced recovery after surgery (ERAS) programs for esophagectomy protocol for a systematic review and meta-analysis. Medicine (Baltim) 2018:97:e0016. [133] Siotos C, Stergios K, Naska A, Frontzas M, Pergialiotis V, Perrea DN, et al. The impact of fast track protocols in upper gastrointestinal surgery: a meta-analysis of observational studies. Surgeon 2018;16:183-92. [134] Mortensen K, Nilsson M, Slim K, Schafer M, Mariette C, Braga M, et al. Consensus guidelines for enhanced recovery after gastrectomy: enhanced recovery after Surgery (ERAS®) Society recommendations. Br J Surg 2014:101:209-22. [135] Wang LH, Zhu RF, Gao C, Wang SL, Shen LZ. Application of enhanced recovery after gastric cancer surgery: an updated meta-analysis. World J Gastroenterol 2018:24:1562-78. [136] Balzano G, Zerbi A, Braga M, Rocchetti S, Beneduce AA, Di Carlo V. Fast-track recovery programme after pancreatico- duodenectomy reduces delayed gastric empty. Br J Surg 2008:95:1387-93. [137] Braga M, Pecorelli N, Ariotti R, Capretti G, Greco M, Balzano G, et al. Enhanced recovery after surgery pathway in patients undergoing pancreatic coducodenectomy. World J Surg 2014:38:2960-6. [138] Ji HB, Zhu Wt, Wei Q, Wang XX, Wang HB, Chen QP. Impact of enhanced recovery after surgery programs on pancreatic surgery: a meta-analysis. World J Gastroenterol 2018:24:1666-78. [139] Kannan V, Ullah N, Geddada S, Ibraham A, Munak Shafir Al-Qassab Z, Ahmed O, et al. Impact of "Enhanced Recovery after surgery" (ERAS) protocols vs. traditional perioperative care on patient outcomes after colorectal surgery: a systematic review. Patient Saf Surg 2025:19:4. [140] Gianotti L, Nespioli L, Terselli L, Panelli M, Nespioli A. Safety, feasibility, and tolerance of early oral feeding after colorectal resection outside an enhanced recovery after surgery (ERAS) program. Int J Colorectal Dis 2011:26:747-33. [141] da Fonseca LM, Profeta da Luz MM, Lacera-Filho A, Correia MI, Gomes da Silva R. A simplified rehabilitation program for patients undergoing elective colonic surgery-randomized controlled clinical trial. Int J Coloreal Dis agectomy. Ann Thorac Surg 2019:107:912-20. [142] Kun Sih, Li Y, Liu XB, Wang ZF, Zhang RX, Lerut T, et al. Impact of an early oral feeding protocol on inflammatory cytokine changes after esophagectomy. Ann Thorac Surg 2019:107:912-20. [143] Carrere N, Seulin P, ClH, Bloom E, Guozi JL, Pradere B. Is nasogastric or nasojejunal decompression necessary after gastrectomy? A prospective randomized trial. World J Surg 2007:31:122-7. [144] Willcuts KF, Chung M, Encenberg CL, Finn KL, Schirmer BD, Byham-Gray LD. Early oral feeding as compared with traditional timing of oral feeding after upper gastrointestinal surgery: a systematic review and meta-analysis. Ann Surg 2016:24:54-63. [145] Zheng R, Devin CL, Pucci MJ, Berger AC, Rosato EL, Palazzo F. Optimal timing and route of nutritional support after esophagectomy: a review of the literature. World J Gastroenterol 2019:25:4427-36. [146] Sun HB, Li Y, Liu XB, Zhang RX, Wang ZF, Lerut T, et al. Early oral feeding following minimally invasive esophagectomy: an open-label, randomized, controlled, noninferiority trial. Ann Surg 2018;267:435-42. [147] Berkelmans GHK, Fransen LFC, Dolmans-Zwartjes ACP, Kouwenhoven EA van Det MJ, Nilsson M, et al. Direct oral feeding following minimally invasive esophagectomy (NTRENTI 11 trial): an international, multicenter, open-label randomized controlled trial. Ann Surg 2020:271:41-7. [148] Zhang C, Zhang M, Gong L, Wu W. The effect of early oral feeding after esophagectomy (NTRENTI 11 trial): an international, multicenter, open-Postgrad Med J 2020:132:419-25. [149] Mahmoodzadeh H, Shoar S, Sirai F, Khorgami Z. Early initiation of oral feeding following upper gastrointestinal surgery: a randomized controlled trial. Surg Today 2015:45:203-8. [150] Sun HB, Li Y, SanzK, Wang ZX, ZF, Qin J, Yan M, et al. Early oral feeding following thoracolaraposcopic oesophagectomy for esophageal cancer. Eur J Cardio Thorac Surg 2015:47:227-33. [161] Speicher JE, Gunn TM, Rossi NP, Iannettoni MD. Delay in oral feeding is associated with a decrease in automatic leak following transhalat esophagectomy. Semin Thorac Cardiovasc Surg 2018:30:476-84. [172] Eberhard KE, Achiam MP, Rolf HC, Belomhoud M, Svendsen LB, Thorsteinsson M. Comparison of "Null by mouth" versus early oral intake in esophagectomy (NTRENTI 11 trial): an international, multicenter, open-label randomized controlled trial. Ann Surg 2020:271:41-73. [183] Jamel S, Tukanova K, Markar SR. The evolution of fast track protocols after esophagectomy. J Thorac Dis 2019:11:5675-84. [154] Liu X-B, Xing W-Q, Sun H-B. Early oral feeding following esophagectomy. J Thorac Dis 2019:11:5824-30.

[155] Fujii T, Nakao A, Murotani K, Okamura Y, Ishigure K, Hatsuno T, et al. Influence of food intake on the healing process of postoperative pancreatic fistula after pancreatoduodenectomy: a multi-institutional randomized controlled trial. Ann Surg Oncol 2015;22:3905–12. [156] Schwenk W, Bohm B, Haase O, Junghans T, Muller JM. Laparoscopic versus conventional colorectal resection: a prospective randomised study of postoperative ileus and early postoperative feeding. Langenbecks Arch Surg 1998; 383:49–55. [157] Bardram L, Funch-Jensen P, Kehlet H. Rapid rehabilitation in elderly patients after laparoscopic colonic resection. Br J Surg 2000;87:1540–5. [158] Chen HH, Wexner SD, Mroatulam AJ, Pikarsky AJ, Alabaz O, Nogueras JJ, et al. Laparoscopic colectomy compares favorably with colectomy by laparotomy for reduction of postoperative ileus. Dis Colon Rectum 2000;43:61–5. – 8. – 9. – 10. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12. – 11. – 12

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[182] Mazolewski P, Turner JF, Baker M, Kurtz T, Little AG. The impact of nutritional status status on the outcome of lung volume reduction surgery: a prospective study. Chest 1999;116:693-6. [183] Mohler JL, Flanagan RC. The effect of nutritional status and support on morbidity and mortality of bladder cancer patients treated by radical cystectomy. J Urol 1987:137:404-7. [184] lezu K, Yoshikawa M, Yoneda T, Kushike K, Kawaguchi T, Kimura M. et al. The effect of nutritional status on morbidity in morbidity at high resolution and longering bilateral lung reduction surgery. Thorac Cardiovasc Surg 2001;49:216-20. [185] Patterson BM. Cornell CN, Carbone B, Levine B, Chapman D. Protein de postion and metabolic stress on elderly patients who a fracture of the hip. J Bone Joint Surg Am 1992;74:251-60. [186] Pedersen NW, Pedersen D. Nutrition as a prognostic indicator in amputations. A prospective study of 47 cases. Acta Orthop Scand 1992;63:675-8. [187] Rey-Ferro M, Castño R, Orozco O, Serna A, Moreno A. Nutritional and immunologic evaluation of patients with gastric cancer before and after surgery. Nutrition 1997;13:878-81. [188] van Bokhorst-de van der Schueren MAE, van Leeuwen PAM, Kuik DJ, Klopp MWC, Saurwein HP, New GSar, B et al. The impact of nutritional status on the prognoses of with advanced head and neck cancer. Cancer 1999;86:51-29. [189] Banning LBD, Ter Beek L, El Moum M1, Visser L, Zeebegts CJ, Jager-Wittenaar H, et al. Vascular surgery patients at risk for malnutrition are at an increased risk of developing postoperative complications. Ann Vasc Surg 2020;64:213-20. [190] Cao Y, Han D, Zhou X, Han Y, Zhang V, Li H. Effects of preoperative nutrition on postoperative outcomes in esophageal cancer: a systematic review and meta-analysis. Dis Esophagus 2022:35:doab28. [191] Li S, Zhang H, He J, Li S. Relationship between preoperative nutritional indicators and postoperative complications in patients with esophageal cancer: a meta-analysis. Nutr Cancer 2024;76:563-72. [192] Sandstrom R, Drott C. Hyldander A Arfvidsson B, Schersten T, Wickstrom I, et al. The effect of postoperative intravenous feeding (TPN) on outcome following major surgery evaluated in a randomized study. Ann Surg 1993;217:185-95. [193] Hiesmary M, Schindler K, Pernicka E, Schuh C, Schoener-Hekele A, Bauer P, et al. Decreased food intake is a risk factor for mortality in hospitalised patients: the Nutrition Day survey 2006. Clin Nutr 2009;28:484-91. [194] Skeie E, Tangvik RJ, Nymo LS Harthg S, Lassen K, Viste A. Weight loss and BMI criteria in GLIMs definition of malnutrition is associated with postoperative complications following abdominal reactions results from a National Quality Registry. Clin Nutr 2020;39:1593-9. [195] Clark AB, Reijnierse EM, Lim WK, Maier AB. Prevalence of malnutrition comparing the GLIM criteria, ESPEN definition and MST malnutrition risk in geriatric rehabilitation patients: resort. Clin Nutr 2020;39:3504-11. [196] Wobith M, Herbst C, Zur L, Mcerz T, Differs M, Weimann A. Evaluation of malnutrition in patients undergoing major abdominal surgery using MCL that ci-dering and comparing CT and BIA for muscle mass measurement. Clin Nutr ESPEN 2022;50:148-54. [197] Martin L, Giolubasan I, S. Senesse P, Baracos VE. Cancer-associated malnutrition and ct-dering and comparing CT and BIA for muscle mass measurement. Clin Nutr ESPEN 2022;50:148-54. [198] Zhang X, Tang M, Zhang Q, Zhang K-P, Guo Z.-Q, Xu H-X, et al. The GLM criteria as an effective tool for nutrition assessment and survival prediction in older adult cancer patients. Clin Nutr 2021;40:122-34. [199] Cruz-Entohf AJ, Bahat G., Bauer J, Boirite Y, Bnyreio O, Cederholm T, et al. Sarcopenia: revised European consensus on definition and diagnosis. Age Ageing 2019;48:16-31. [197] Barazzoni R, Gortan Cappellari G. Double burden of malnutrition in persons with obesity. Rev Endocr Metab Disord 2021;20:37-13. [201] Dononi LM, Busetto L, Bischoff S C, Gederholm T, Ballesteros-Pomar MD, Batsis JA, et al. Definition and diagnostic criteria for sarcopenic obesity: ESPEN and EASO consensus statement. Obes Facts 2022;15:321-35. [202] Gruber ES, Jomrich G, Tamandl D, Gnant M, Schindl M, Sahara K. Sarcopenia and sarcopenic obesity are independent adverse prognostic factors in respectable pancreatic ductal adenocarcinoma. PLoS One 2019;42:e0215915. [203] Pecorelli N, Capretti G, Sandini M, Damascelli A, Cristel G, De Cobelli F, et al. Impact of sarcopenic obesity on failure to rescue from major complications following pancreatic productodenectomy for cancer: results from a multicenter study. Ann Surg Oncol 2018;25:308-17. [204] Liu C, Tu Deng, Zhang Q, Song M, Shi J, et al. Sarcopenic obesity of outcomes for patients with cancer. JAMA Netw Open 2024;7:e2417115. [205] Wang P-y, Chen X-k, Liu Q, Yu Y-k, Xu L, Liu X-b, et al. Highlighting sarcopenia management for promoting surgical outcomes on esophageal cancers: evidence from a prospective cohort study. Int J Surg 2020;83:206-15. [206] Paapantostinian D, Vretakakou K, Paspa A, Misiakos EP, Charalampopoulos A, Nastos C et al. The impact of preoperative sarcopenia effect on postoperative complications following esophagectomy for esophageal an neoplasia: a systematic review and meta-analysis. Dis Esphagus 2020;33:daaa02. [207] Mayanag S, Tsubosa Y, Omaa K, Niihara M, Uchida T, Tsushima T, et al. Negative impact of keskinale muscle wasting after neoadjuvant chemotherapy followed by surgery on survival for patients with thoracic esophageal cancer. Ann Surg Oncol 2017;24:3741-7.

[208] Kuwada K, Kikuchi S, Kuroda S, Yoshida R, Takagi K, Noma K, et al. Survival impact of postoperative skeletal muscle loss in gastric cancer patients who underwent gastrectomy. Anticancer Res 2023;43:223-30. [209] Sandini M, Bernasconi DP, Ippolito D, Nespoli L, Baini M, Barbaro S, et al. Preoperative computed tomography to predict and stratify the risk of severe pancreatic fistura after pancreatoduodenectomy. Medicine 2015;94: e152. [210] Giani A, Famularo S, Riwa L, Tamini N, Ippolito D, Nespoli L, et al. Association between specific surgical anthropometric indexes and morbidity in patients undergoing radical cancer resection. Nutrition 2020;75:76-110729. [221] Elliott JA, Doyle SL, Murphy CF, King S, Guinan EM, Beddy P, et al. Sarcopenia: prevalence, and impact on operative and oncologic outcomes in the multimodal management of locally advanced esophageal cancer. Ann Surg 2017;26:822-80.33. [212] Davies SJ, West MA, Rahman SA, Underwood TJ, Marino LV. Oesophageal cancer: the effect of early nutrition support on clinical outcomes. Clin Nut ESPEN 2021;42:117-238. [213] Sandini M, Patino M, Ferrone CR, Alvarez-Pérez CA, Honselmann KC, Paiella S, et al. Association between changes in body composition and neoadjuut treatment for pancreatic cancer. JAMA Surg 2018;153:809-15.89. [214] Mourtzka CM, Lieffers JR, Reiman T, McCargar LJ, Baracos VE. A practical and precise approach to quantification of body composition in cancer patients using computed tomography images acquired during routine care. Appl Physiol Nutr Metabol 2008;33:997-1006. [215] Branco MG, Mateus C, Capelas ML, Pimenta N, Santos T, Mäkitie A, et al. Bioelectrical impedance analysis (BIA) for the assessment of body composition in oncology: a scoping review. Nutris 2023;15:4792. [216] Famularo S, Donadon M, Roccamatisi L, Di Lucca G, Angrisani M, Baccalini E, et al. Association of indirect measurement of cell function by bioimpedance analysis with the complications in oncologic hepatic surgery. HPB 2023;25:2832-92. [217] Sandini M, Gianotti L, Paiella S, Bernasconi DP, Roccamatisi L, Famularo S, at P. Predicting the risk of morbidity by glim-based nutritional assessment and body composition analysis in oncologic abdominal surgery in the context of enhanced recovery programs: the PHase Angle V, Pempera and Abdominal Surgery (PHAVAS) Study. Ann Surg Oncol 2024;31:3995-4004. [218] Tang HHY, Mok E, Yeung HS, Wei MYK, Yeung JMC. Digital health and medical technology for preactive sarcopenia optimisation and prehabilitation – where to go from here? Eur J Surg Oncol 2024;50:108376. [219] Pena NF, Mauricio SF, Rodrigues AMS, Carmo AS, Coury NC, Correia M, et al. Association between standardized phase angle, nutrition status, and clinical outcomes in surgical cancer patients. Nutr Clin Pract 2019;34:381-6. [220] Wildiers H, Heeren P, Puts M, Topinkova E, Janssen-Heijinen ML, Extermann M, et al. International Society of Geriatric Oncology consensus on geriatric assessment in older patients with cancer. J Clin Oncol 2014;32:2595-603, [221] Saur NM, Davis BR, Montroni I, Shahrokni A, Rostoft S, Russell MM, et al. The American Society of Colon and Rect Surgeons clinical practice guidelines for the perioperative evaluation and management of frailty among older adults undergoing colorectal surgery. Dis Colon Rectum 2022;65:473-88. [222] Eamer G, Taheri A, Chen SS, Daviduck Q, Chambers T, Shi X, et al. Comprehensive geriatric assessment for older people admitted to a surgical service. Cochrane Database Syst Rev 2018;1:CD012485. [223] Feng MA, McL�ow K, Crowell K, Muss H, Nielsen ME, Smith AB. Geriatric assessment in surgical oncology: a systematic review. J Surg Res 2015;193:265-72. [224] Nipp RD, Qian CL, Knight HP, Ferrone CR, Kunitake H, Castillo CF-D, et al. Effects of a perioperative geriatric intervention for older adults with cancer: a randomized clinical trial. J Geriatr Oncol 2022;13:410-5. [225] Mohile SG, Mohamed MR, Xu H, Culakova E, Loh KP, Magnusan A, et al. Evaluation of geriatric assessment and management on the toxic effects of cancer treatment (GAP70+): a cluster-randomised study. Lancet 2021;398:1894-904. [226] Montroni I, Rostoft S, Spinelli A, Van Leeuwen BL, Ercolani G, Saur NM, et al. SOC -gerative oncology surgical assessment and functional rEcovery after surgery: early analysis on 977 patients. J Geriatr Oncol 2020;11:244-55. [227] Brung PF, Halling A, Hilgers FJ, Kappner G, Poelhuis EK, Kobashi-School AM, et al. Postoperative nasogastric tube feeding in patients with head and neck cancer: a prospective assessment of nutritional status and well-being. Eur J Cancer Clin Oncol 1988;24:181-8. [228] Hamaoui E, Lefkowitz R, Olender L, Lrasnopolsky-Levine E, Favale M, Webb H, et al. Enterall nutrition in the early postoperative period: a new semi-elemental formula versus total parenteral nutrition. JPEN - J Parenter Enter Nutr 1990;14:501-7. [229] Hammerlid E, Wirblad B, Sandin C, Merccke C, Edstrom S, Kaasa S, et al. Malnutrition and food intake in relation to quality of life in head and neck cancer patients. Head Neck 1998;20:540-8. [230] Hedberg AM, Lairson DR, Aday LA, Chow J, Suki R, Houston S, et al. Economic implications of an early postoperative enteral feeding protocol. J Am Diet Assoc 1999-99:802-7. [231] Kornowski A, Cosnes J, Gendre JP, Quintrec Y. Enteral nutrition in malnutrition following gastric resection and cephalic pancreaticoduodenectomy. Hepatogastroenterology 1992;39:9-13.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[232] Mochizuki H, Togo S, Tanaka K, Endo I, Shimada H. Early enteral nutrition after hepatectomy to prevent postoperative infection. Hepatogastroenterology 2000;47:1407–10. [233] Moore FA, Feliciano DV, Andrassy Rj, McArdle AH, Booth FV, Morgenstein-Wagner TB, et al. Early enteral feeding, compared with parenteral, reduces postoperative septic complications. The results of a meta-analysis. Ann Surg 1992;216:172–83. [234] Neumayer LA, Smout RJ, Horn HG, Horn SD. Early and sufficient feeding reduces length of stay and charges in surgical patients. J Surg Res 2001;95: 73–7. [235] Shaw-Stiffel TA, ZAry, LA lehan PEW, REOSman DD, Rudolph RA, Bernstein LH. Effect of nutrition status and other factors on length of hospital stay after major gastrointestinal surgery. Nutrition 1993;9:140–5. Velez Q, Lince LF, Lrestorepo JL. Early enteral nutrition in gastrointestinal surgery: a pilot study. Nutrition 1997;13:442–5. [237] Weimann A, Selberg O, Schuster HP, Müller MJ, Adolph M, Behrend Wt, et al. Kriterien der Überwachung und des Erfolgs einer künstlichen Ernähung ? Loccumer Gespräche 1997. Intensivmed Notfallmed 1997;34:744–8. [238] Weimann A, Müller MJ, von Herz U, Arends J, Dörries A, Keymling M, et al. Lebensqualität à Kriterium des Erfges eine künstlichen Ernähung. Intensivmed Notfallmed 1998;35:724–6. [239] Adams S, Dellinger EP, Wertz MJ, Oreskovich MR, Simonowitz D, Johansen K. Enteral versus parenteral nutritional support following laparotomy for trauma: a randomized prospective trial. J Trauma 1986;26: 882–91. [240] Baigrie RJ, Devitt PG, Watkin DS. Enteral versus parentral nutrition after rotomagistic surgery: a prospective randomized comparison. ANZ J Surg 1996;66:668–70. [241] Bastow MD, Rawlings J, Allison SP. Benefits of supplementary tube feeding after fractured neck of femur: a randomized controlled trial. Br Med J (Clin Res Ed) 1983;287:1589–92. [242] Beatie AH, Frach AT, Baxter JP, Pennington CR. A randomised controlled trial evaluating the use of entoral nutritional supplements postoperatively in malnourished surgical patients. Gut 2000;46:813–8. Beier-Holgersen R, Boesby S. Influence of postoperative eternal nutrition on posturgical infections. Gut 1996;39:833–5. [243] Bower RH, Talamini MA, Sax HC, Hamilton F, Fischer JE. Postoperative enteral vs parenteral nutrition. A randomized controlled trial. Arch Surg 1986;121:1040–5. [245] Bozzetti F, Braga M, Gianotti L, Gavazzi C, Mariani L. Postoperative enteral versus parental nutrition in malnourished patients with gastrointestinal�cer, a randomized multicamente trial. Crit Care Med 2001;38:148–92. [246] Braga M, Gianotti L, Gentilini O, Parisi V, Salis C, Di Carlo V. Early postoperative enteral nutrition improves gut oxygenation and reduces costs compared with total parenteral nutrition. Crit Care Med 2001;29:242–8. [247] Carr CS, Ling KD, Boulos P, Singer M. Randomised trial of safety and efficacy of immediate postoperative enteral feeding in patients undergoing gastrointestinal resection. Br Med J 1996;312:869–71. [248] Delmi R, Papin CH, Bengoa JM, Delmas PD, Vasey H, Bonjour JP. Dietary supplementation in elderly patients with fractured neck of the femur. Lancet 1990;335:1013–6. [249] Espaellu J, Guyer H, Diaz-Escriu F, Mellado-Navas JA, Castells M, Pladevall M. Nutritional supplementation of elderly hip fracture patients. on Multientized, double-blind, placebo-controlled trial. Age Ageing 2000;29:425–31. [250] Iovinlië G, Marsili I, Varrassi G. Nutrition support after total laryngetomy. J PEN-J. Parenter Enter Nutr 1993;17:445–8. [251] Keeek AM, Bray MJ, Emery PW, Duncan HD, Silk DB. Two phase randomised controlled clinical trial of postoperative oral dietary supplements in surgical patients. Gut 1997;40:393–9. [252] Kudsk KA, Croce MA, Fabian TC, Minard G, Tolley EA, Poret HA, et al. Enteral versus parenteral feeding. Effects on septic morbidity after blunt and penetrating abdominal trauma. Ann Surg 1992;215:503–11. discussion of last 11:34–11. 22:11–12. 23:33–33. 14:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–34. 13:34–3

in patients after major upper gastrointestinal surgery? JPEN - J Parenter Enter Nutr 1997; 21:196-201, [260] Ryan Jr JA, Page CP, Babcock L. Early postoperative jejunal feeding of elemental diet in gastrointestinal surgery. Am Surg 1981;47:393-403. [261] Sagar S, Harland P, Fields R. Early postoperative feeding with elemental diet. Br Med J 1979;1:293-5. [262] Sand J, Luostarines M, Matikainen M. Enteral or parenteral feeding after total gastrectomy: prospective randomised pilot study. Eur J Surg 1997;163:761-6. [263] Schroeder D, Gillanders L, Mahr K, Hill GL. Effects of immediate post-operative enteral nutition on body composition, muscle function, and wound healing. JPEN - J Parenter Enter Nutr 1991;15:376-83. [264] Shirabe K, Matsumata T, Shimada K, Takenaka K, Kawahara N, Yamamoto K, et al. A comparison of parenteral hyperalimentation and early enteral feeding regarding systemic immunity after major hepatic resection-the results of a randomized prospective study. Hepatogastroenterology 1997;44:205-9. [265] Shukla HS, Rao RR, Bau N, Gupta RM, Yadav RC. Enteral hyperalimentation in malnourished cultural patients. Indian J Med Res 1984;80:339-46. [266] Singh G, Ram RP, Khana SK. Early postoperative enteral feeding in patients with nontraumatic intestinal perforation and peritonitis. J Am Coll Surg 1998;187:142-6. [267] Smedley F, Bowling T, James M, Stokes E, Goodger C, O'Connor O, et al. Randomized clinical trial of the effects of preoperative and postoperative oral nutritional supplements on clinical course and cost of care. Br J Surg 2004;91:983-90. [268] Smith RC, Hartemink JR, Hollinshead JW, Gillett DJ. Fine bore jeunostomy feeding following major abdominal surgery: a controlled randomized clinical trial. Br J Surg 1985;72:458-61. [269] Sullivan DH, Nelson Cl, Bopp MM, Puskarich-May CL, Walls RC. Nightly enteral nutrition support of elderly hip fracture patients: a phase I trial. J Am Coll Nutr 1998;17:155-61. [275] Sullivan DH, Nelson Cl, Klimberg VS, Bopp MM. Nightly enteral nutrition support of elderly hip fracture patients: a pilot study. J Am Coll Nutr 2004;23:683-91. [287] Von Meyerfeld F, Meijerink WJ, Rouflart MM, Builmaassen MT, Soeters PB. Perioperative nutritional support: a randomised clinical trial. Clin Nutr 1992;11:180-6. [297] Watters JM, Kirkpatirk SM, Norris SB, Shamji FM, Wells GA. Immediate postoperative enteral feeding results in impaired respiratory mechanics and decreased mobility. Ann Surg 1997;226:369-77. discussion 77-80. [287] Martignoni ME Fries H, Sell E Ricken J, Srikbande S, Kulli C et al. Enteral nutrition prolongs delayed gastric emptying in patients after Whipple resection. Am J Surg 2000;180:18-23. [274] Dunham CM, Frankenfield D, Belzberg H, Wiles C, Cushing B, Grant Z. Gut failure—predictor of autor contributor to mortality in mechanically ventilated blunt trauma patients? J Trauma 1994;37:30-4. [275] Weimann A, Hart WH, Adolph M, Angstwurm M, Brunkhorst FM, Edel A, et al. Fassung under Gapparatives Monitoring des Ernährungsstatus von Patient* innen auf der Intensiv-und Intermediate Care Station. Med Klin Intensivmed Notfallmed 2022;117:37-50. [276] Beier-Holgard, Hochandtrup B. Influence of early postoperative enteral nutrition versus placebo on cell-mediated immunity, as measured with the Multitres CML scand | Gastroenterol 1999;34:98-102. [277] Brooks AD H, Hochandtrup N, Heslin MJ, Harrison LE, Burt M, Brennan MF. In-testinal permeability after early postoperative enteral nutrition in patients operative gastrointestinal malignancy. JPEN - J Parenter Enter Nutr 1999;23:75-9. [278] Fletcher JP, Little JM. A comparison of parenteral nutrition and early postoperative enteral feeding improves whole body protein kinetics in upper Surgery 1986;100:21-44. [279] Hochwald SN, Harrison LE, Heslin MJ, Burt ME, Brennan MF. Early postoperative enteral feeding improves whole body protein kinetics in upper gastrointestinal patient. Am J Surg 1997;174:325-30. [280] Hu QG, Zheng QC. The influence of enteral nutrition in postoperative patients with poor liver function. World J Gastroenterol 2003;9:843-6. [281] Hwang TL, Huang SL, Chen MF. Early nasoduodenal feeding for the post-biliary surgical patient. J Formos Med Assoc 1991;90:993-7. [282] Lim ST, Choa RG, Lam KH, Wong, Jong G. Bual. Total parental nutrition versus gastrostomy in the preoperative preparation of patients with carcinoma of the oesophagus. Br J Surg 1981;68:69-72. [283] Magnusson J. Tranberg KG, Jeppsson B, Lunderquist A. Enteral versus parental glucose as the sole nutritional support after colorectal resection. A prospective, randomized comparison. Scand J Gastroenterol 1989;24:539-49. [284] McArdie AH, Reid EC, Laplante MP, Freeman CR. Prophylaxis against radiopostary and ideal element diet prior to and during radiotherapy for invasive bladder cancer and in early postoperative feeding following radical cystonath and ideal conduit. Arch Surg 1986;121:879-85. [285] Nissil MS, Havia TV. Natural killer cell activity after immediate postoperative enteral and parenteral nutrition. Acta Chir Scand 1989;155:229-32. [286] Suchner U, Senfleben U, Eckart T, Scholz MR, Beck K, Murr R, et al. Enteral versus parenteral nutition: effects on gastrointestinal function and metabolism. Nutrition 1996;12:12-22.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[287] Zhang L, Liu Y, Gao X, Zhou D, Zhang Y, Tian F, et al. Immediate vs. gradual advancement to goal of enteral nutrition after elective abdominal surgery: a multicenter non-inferiority randomized trial. Clin Nutr 2021: 40:5802-11. [288] Elia M, Normand C, Norman K, Laviano A, A systematic review of the cost and cost effectiveness of using standard oral nutritional supplements in the hospital setting. Clin Nutr 2016:35:370-80. [289] Cillis C, Buhler K, Bresee L, Carl F, Gramlich L, Culos-Reed N et al. Effects of nutritional prehabilitation, with and without exercise, on outcomes of patients who undergo colorectal surgery: a systematic review and meta-analysis. Gastroenterology 2018:15:35:410-41 e, [289] Lider P, Flanagan D, Fleming S, Russell M, Morgan N, Wheatley T, et al. Combining enteral with parenteral nutrition to improve postoperative glucose control. Br J Nutr 2010: 103:635-41. [281] Dhaliwal R, Jurewisch B, Harrietha D, Heyland DK. Combination enteral and parenteral nutrition in critically ill patients: harmful or beneficial? A systematic review of the evidence. Intensive Care Med 2004:30:1666-71. [292] Casaer MP, Mesotten D, Hermans G, Wouters PJ, Schetz M, My Froidtoid G, et al. Early versus late parenteral nutrition in critically ill adults. N Engl J Med 2011:36:506-17. [293] Heidegger CP, Berger MM, Graf S, Zingberg W, Darmon P. Costanza MC, et al. Optimisation of energy provision with supplemental parenteral nutrition in critically ill patients: a randomised controlled clinical trial. Lancet 2013:381:385-93. [294] McCowner KC, Friel C, Sternberg J, Chan S, Forse RA, Burke PA, et al. Hypo-caloric total parenteral nutrition: effectiveness in prevention of hyperglycemia and infectious complications-a randomized clinical trial. Critic Care Med 2000:28:3606-11. [295] Singer P, Blaser AR, Berger MM, Alhazzani W, Calder PC, Casaer MP, et al. ESPEN guideline on clinical nutrition in the intensive care unit. Clin Nutr 2019:38:48-79. [296] Gao X, Liu Y, Zhang L, Zhou D, Tian F, Gao T, et al. Effect of early sul developmental parenteral nutrition in patients undergoing abdominal surgery: a randomized clinical trial. JAMA Surg 2022;157:384-93. [297] Wu W, Zhong M, Zhu DM, Song JQ, Huang JF, Wang Q, et al. Effect of early full-calorie nutrition support following esophagectomy: a randomized controlled trial. JPEN - J Parenter Entur Nutr 2017:41:1146-54. [298] Woodcock NP, Zeigler D, Palmer MD, Buckley P, Mitchell J, MacFie J. Enteral versus parenteral nutrition: a pragmatic study. Nutrition 2001:17:1-12. [299] Gianotti L, Paiella S, Capretti G, Pecorelli N, Frigerio I, Sandini M, et al. Supplemental parenteral nutrition within an enhanced recovery program for open pancreatodudentectomy for cancer: a pragmatic, multicenter, randomized controlled trial. eClinical Medicine 2025. https://doi.org/10.1016/j.eclinm. Penup. head ahead of print. [300] Perinel J, Mariette C, Dousset B, Sielezneff I, Gainant A, Mabrut JY, et al. Early enteral versus total parenteral nutrition in patients undergoing pancrecatoduodentomy: a randomized multicenter controlled trial (NutR-DPC). Ann Surg 2016;264:731-7. [301] Bozzetti F, Gavazzi C, Miceli R, Rossi N, Mariani I, Cozzaglio L, et al. Peri-operative total parenteral nutrition in malnourished, gastrointestinal cancer patients: a randomized, clinical trial. JPN - J Parenter Enter Nutr 2000:24:7-14. [302] Brennan MF, Pisters PW, Posner M, Quesada O, Shike M. A prospective randomized trial of total parenteral nutrition after major pancreatic resection for malignancy. Ann Surg 1994:220:436-41. discussion 41-4. [303] Fan ST, Lo CM, Lai EC, Chu KM, Liu Cl, Wong J. Perioperative nutritional support in patients undergoing hepatectomy for hepatocellular carcinoma. N Engl J Med 1994:331:1547-52. [304] Hu SS, Fontaine F, Kelly B, Bradford DS. Nutritional depletion in staged spinal reconstructive surgery. The effect of total parenteral nutrition. Spine (Phila Pa 1976) 1998:23:1401-5. [305] Jauch KW, Hartl WH, Georgieff M, Wolfe RR, Dietze GJ, Gunther B, Low-dose bradykinin infusion reduces endogenous glucose production in surgical patients. Metabolism 3888:17:38-95. [306] Reilly J, Mehta R, Teperman L, Cemaj S, Tzakis A, Yanaga K, et al. Nutritional support after liver transplantation: a randomized prospective study. JPEN J - Parenter Enter Nutr 1990:14:386-91. [307] Veterans Affairs Total Parenteral Nutrition Cooperative Study Group. Perioperative total parental nutrition in surgical patients. N Engl J Med 1991:325:525-32. [308] Wicks C, Somasundaram S, Bjarnason I, Menzies IS, Routley D, Potter D, et al. Comparison of enteral feeding and total parenteral nutrition after liver transplantation. Lancet 1994:344387-40. [309] Gao X, Zhang Y, Zhang Y, Zhou D, Gao T, Liu Y, et al. Effect of early achievement of energy target by different nutritional support strategies on nosocomial infections in patients undergoing major abdominal surgery: a secondary analysis of two randomized clinical trials. Int J Surg 2023:109:2680-8. [301] Gao X, Zhang Y, Qi X Xiao Y, Gao T, Jin G, et al. Early ental nutrition versus early sul, Metabolism 1888:31:140-51. [307] Hea Chuk, Wertl WH, Georgieff M, Wolfe RR, Dietze GJ, Gunther B, Low-dose bradykinin infusion reduces endogenous glucose production in surgical patients. Metabolism 2888:17:38-95. [308] Reilly J, Mehta R, Teperman L, Cemaj S, Tzakis A, Yanaga K, et al. Nutrational support after liver transplantation: a randomized prospective study. JPEN J - Parenter Enter Nutr 1990:14:386-91. [307] Veterans Affairs Total Parenteral Nutrition Cooperative Study Group. Perioperative total parental nutrition in surgical patients. N Engl J Med 1991:325:525-32. [308] Wicks C, Somasundaram S, Bjarnason I, Menzies IS, Routley D, Potter D, et al. Comparison of enteral feeding and total parenteral nutrition after liver transplantation. Lancet 1994:344387-40. [309] Gao X, Zhang L, Zhang Y, Zhou D, Gao T, Liu Y, et al. Effect of early achievement of energy target by different nutritional support strategies on nosocomial infections in patients undergoing major abdominal surgery: a secondary analysis of two randomized clinical trials. Int J Surg 2023:109:2680-8. [307] Gao X, Zhang Y, Qi X Xiao Y, Gao T, Jin G, et al. Early ental nutrition versus early sul, Metabolism 2888:17:38-95. [308] Hea Chuk, Wertl WH, Georgieff M, Wolfe RR, Dietze GJ, Gunther B, Low-dose bradykinin infusion reduces endogenous glucose production in surgical patients. Metabolism 2888:17:38-95. [309] Perike R, Mehta R, Teperman L, Cemaj S, Tzakis A, Yanaga K, et al. Nutrational support after liver transplantation: a randomized prospective study. JPEN J - Parenter Enter Nutr 2000:23:57-325-32. [308] V店en S, Gomasundaram S, Bjarnason I, Menzies IS, Routley D, Potter D, et al. Comparison of enteral feeding and total parenteral nutrition after liver transplantation. Lancet 1994:344387-40. [309] Gao X, Zhang Y, Zhang Y, Zhou D, Gao T, Liu Y, et al. Effect of early achievement of energy target by different nutritional support strategies on nosocomial infections in patients undergoing major patient volume of nonocomial infections in patients. Uniglio perenter Enter Nutr 2003:27:241-5. [307] Hea Chuk, Wertl WH, Georgieff M, Wolfe RR, Dietze GJ, Gunther B, Low-dose bradykinin infusion reduces endogenous glucose production in surgical patients. Metabolism 2888:17:38-95. [308] Hea Chuk, Wertl WH, Georgieff M, Witrert D, Man, Wiberman L, Burgeon AF, Eshraghi N, et al. A randomized trial of enteral glutamine for treatment of burn injuries: N Engl J Med, Zhao Wu, XI, Ja, M, EL et al. The impact of alanyl-glutamine on clinical safety, nitrogen balance, intestinal permeability, and clinical outcome in postoperative patients: a randomized, double-blind, double-blind, 278-86.

[312] McClave SA, Taylor BE, Martindale RG, Warren MM, Johnson DR, Braunschweig C, et al. Guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient: society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.), PEN - J Parenter Enter Nutr 2016;40:159-211. [313] Zhao XF, Wu N, Zhao GQ, Liu JF, Dai YF. Enteral nutrition versus parenteral nutrition after major abdominal surgery in patients with gastrointestinal cancer: a systematic review and meta-analysis. J Invest Med 2016;64:1061-74. [314] Harvey SE, Parrott F, Harrabon D, Beale R, Beale R, et al. Trial of the route of early nutritional support in critically ill adults. N Engl J Med 2014;371:1673-84. [315] Teja B, Bosch NA, Diep C, Pereira TV, Mauricio P, Sklar MC, et al. Complication rates of central venous catheters: a systematic review and meta-analysis. JAMA Intern Med 2024;184:474-82. [316] Sánchez-Guillen L, Soriano-lrigaray L, López-Rodríguez-Arias F, Barber X, Murcia A, Alcaide MJ, et al. Effect of early peripheral parenteral nutrition support in an enhanced recovery program for colorectal cancer surgery: a randomized open trial. J Clin Med 2021;10. [317] López-Rodríguez-Arias F, Sánchez-Guillén L, Lillo-García C, Aranaz-Aranz-Viase, Aléars-Ariš, Jus (A.S. Residen S. Luca, 13) et al. Assessment of body composition as an indicator of early peripheral parenteral nutrition therapy in patients undergoing colorectal cancer surgery in an enhanced recovery program. Nutrients 2021;13. [318] Senkal M, Bonavina L, Reith B, Caruso R, Matern U, Duran M. Perioperative peripheral parenteral nutrition to support major gastrointestinal surgery: expert opinion on treating the right patients at the right time. Clin Nutr ESPEN 2021;43:164. [319] Durán-Poveda M, Bonavina L, Reith B, Caruso R, Klek S, Senkal M. Nutrition practices with a focus on parenteral nutrition in the context of enhanced recovery programs: an exploratory survey of gastrointestinal surgeons. Clin Nutr ESPEN 2022;50:138-47. [320] Nmenre R, Adolph M, Brock E, Schneider H, Senkal M. Cost analysis of parenteral nutrition regimens in the intensive care unit: three-compartment bag system vs multitottle system. JPEN - J Parenter Enter Nutr 2008;32:606-12. [321] Pichard C, Schwarz G, Frei A, Kyle U, Jolliet P, Morel P, et al. Economic investigation of the use of three-compartment total parenteral nutrition bag: prospective randomized unblinded controlled study. Clin Nutr 2000;19:245-51. [322] Yu J Wu G, Tang Y, Ye Z. Zhang Z. Efficacy, safety, and preparation of standardized parenteral nutrition regimens: three-chamber bags vs compounded monobags-a prospective, multicenter, randomized, single-blind clinical trial. Nutr Clin Pract 2017;32:545-51. [323] Turpin RS, Canada T, Desenthal V, Nitzki-George D, Liu FX, Mercaldi CJ, et al. Bloodstream infections in the United states: a retrospective, large database analysis. JPEN - J Parenter Enter Nutr 2012;36:169-76. [324] Heyland D, Muscedere J, W. Wischmeyer PE, Cook D, Jones G, Albert M, et al. A randomized trial of glutamine and antioxidants in critically ill patients. N Engl J Med 2013;368:1489-97. [325] Wernerman J, What is actually attributable to glutamine? JPEN - J Parenter Enter Nutr 2017;41:9. [326] Wernerman J, How to understand the results of glutamine sup- setion for median; Crit. Care 2015;19:385. [327] van Zanten AR, Hofman Z. Standard vs enriched high protein enteral nutrition in the ICU-reply. JAMA 2014;31:22288-9. [328] van Zanten AR, Hofman Z, Heyland DK. Consequences of the REDOXS and METAPLUS trials: the end of an era of glutamine and antioxidant supple- mentation for critically ill patients? JPEN - J Parenter Enter Nutr 2015;39:805-2. [329] van Zanten AR, Sztark F, Kaisers UX, Zielmann S, Felbinger TW, Sablotzki AR, et al. High-protein enteral nutrition enriched with immune-modulating nutrients vs standard high-protein enteral nutrition and nosocomial in- fects in the ICU: a randomized clinical trial. JAMA 2014;31:51:24-24. [330] Conejero K, Bonet A, Grau T, Esteban A, Mesejo A, Montejo JC, et al. Effect of a glutamine-enriched enteral diet on intestinal permeability and infectious morbidity at 28 days in critically ill patients with systemic inflammatory response syndrome. Nutrition 2002;18:716-21. [341] García-de-Lorenzo A, Garazaga A, García-Luna PP, Gonzalez-Huix F, López-Martínez J, Miján A, et al. Clinical evidence for enteral nutritional support with glutamine. Nutrition 2003;19:805-11. [353] Zhou HAp, Rijnsburger ER, Jansen J, Wesdorp RI, Weiss JK, Mcamish MA, et al. Randomised trial of glutamine-enriched enteral nutrition on infectious morbidity in patients with multiple trauma. Lancet 1998;352:772-6. [363] Zhou YP, Jiang ZM, Sun YH, Wang XR, Ma EL, Wilmore D. The effect of supplemental elemental vitamine on plasma levels, gut function, and outcome in severe burns: a randomized, double-blind, controlled clinical trial. JPEN - J Parenter Enter Nutr 2003;27:241-5. [374] Heidung IX, Pollack JA, Friedman B, Turgeon AF, Eshraghi N, et al. A randomized trial of enteral glutamine for treatment of burn injuries. N Engl J Med 2022;387:1001-10. [383] Jian ZM, Cao JD, Zhu XG, Zhao WX, Yu JC, Ma EL, et al. The impact of alanyl-glutamine on clinical safety, nitrogen balance, intestinal permeability, and clinical outcome in postoperative patients: a randomized, double-blind,

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

controlled study of 120 patients. JPEN - J Parenter Enter Nutr 1999;23: S62-6. [336] Bollhalder L, Pefi AM, Tomonaga Y, Schwenkglenks M. A systematic literature review and meta-analysis of randomized clinical trials of parenteral glutamine supplementation. Clin Nutr 2013;32:213-23. [337] Wang Y, Jiang ZM, Nolan MT, Jiang H, Han HR, Yu K, et al. The impact of glutamine dipeptide-supplemented parenteral nutrition on outcomes of surgical patients: a meta-analysis of randomized clinical trials. JPEN - J Parenter Enter Nutr 2010;34:521-9. [338] Kang K, Shu XL, Zhang YS, Liu XL, Zhao J. Effect of glutamine enriched nutrition support on surgical patients with gastrointestinal tumor: a meta-analysis of randomized controlled trials. Chin Med J (Engl Ed) 2015;128: 245-51. [339] Sandini M, Nespioli L, Oldani M, Bernasconi DP, Gianotti L. Effect of glutamine dipeptide supplementation on primary outcomes for elective major surgery: systematic review and meta-analysis. Nutrients 2015;7:481-99. [340] Yang T, Yan X, Cao, Y B, Ti, G, Gu S, et al. Meta-analysis of glutamine on immune function and post-operative complications of patients with colorectal cancer. Front Nutr 2021;8:765809. [351] Cui Y, Hu L, Liu Y, Wu y-M, Jin Y, Ling L intravenous alany-L-glutamine balanes glucose-insulin homeostasis and facilitates recovery in patients undergoing colonic resection: a randomised controlled trial. Eur J Anaesthesiol 2014;31:212-8. [342] Gianotti L, Braga M, Biff R, Bozzetti F, Mariani L, Glutamltaly Research Group of the Italian Society of Parenteral and Enteral Nutrition. Perioperative intravenous glutamine supplementation in major abdominal surgery for cancer: a randomized multicenter trial. Ann Surg 2009;250: 684-90. [343] Ziegler TR, May AK, Hebbar G, Easley KA, Griffith DP, Dave N, et al. Efficacy and safety of glutamine-supplemented parenteral nutrition in surgical ICU patients: an American multicenter randomized controlled trial. Ann Surg 2016;263:646-55. [344] Fearon KC, Ljungqvist V, On Meyenfeldt M, Revhaug A, Dejong CH, Lassen K, et al. Enhanced recovery after surgery: a consensus review of clinical care for patients undergoing colonic resection. Clin Nutr 2005:24:46-77. [345] McSorley ST, Watt DG, Horgan PG, McMillan DC. Postoperative systemic inflammatory response, complication severity, and survival following surgery for colorectal cancer. Ann Surg Oncol 2016;23:2832-40. [346] Tan HB, Danilla S, Murray A, Serra R, El Dib R, Henderson TO, et al. Immunonstitution as an adjuvant therapy for burns. Cochrane Database Syst Rev 2014;4:12-C0007174. [347] Okamoto Y, Sakaguchi T, Ikematsu Y, Kani T, Hirayama K, Tamura H, et al. Early enteral nutrition with arginine compensates for negative nitrogen balance in patients undergoing curative total gastrectomy. J Med investig 2023;70:35-33. [348] Vidal-Casariego A, Calleja-Fernandez A, Villar-Taibo R, Kykiaros G, Balles-teros-Pomar MD. Efficacy of arginine-enriched internal formulas in the reduction of surgical complications in head and neck cancer: a systematic review and meta-analysis. Clin Nutr 2014;33:951-7. [349] Buijis N, van Bokhorde-34 van der Schueren MA, Langius JA, Leemans CR, Kuik DJ, Vermeulen MA, et al. Perioperative arginine-supplemented nutrition in malnourished patients with head and neck cancer improves long-term survival. Am J Clin Nutr 2010;92:1151-6. [350] Adiamah A, Rollin KE, Kapeliser A, Welch NT, Iftikhar SY, Allison SP, et al. Postoperative arginine-enriched immune modulating nutrition: long-term survival results from a randomised clinical trial in patients with oesopha-gogastric and pancreaticboiliary cancer. Clin Nutr 2021;40:5482-5. [351] Lobo DN, Williams RN, Welch NT Aloysius MM, Nunes QM, Padmanabhan J, et al. Early postoperative jeunostomying feeding with an immune modulating diet in patients undergoing resectional surgery for upper gastrointestinal cancer: a prospective, randomized, controlled, double-blind study. Clin Nutr 2006;25:716-26. [354] Lu, S Yang, Z Tang H, Sun X, Wang B, Qu J, et al. Associations between omega-3 polyunsaturated fatty acids supplementation and surgical pro-geding in patients with gastrointestinal cancer: a systematic review and meta-analysis. Food Chem22:409.4002-49. [355] Serhan CN, Bäck M, Churichü V, Hersberger M, Mittendorfer B, Calder PC, et al. Expert consensus report on lipid medators: role in resolution of inflammation and muscle preservation. FASEB J 2024;38:38e:23699. [354] Gae HJ, Lee GY, Seong JM, Gwak HS. Outcomes with perioperative fat emulsions containing oneega-3 fatty acid: a meta-analysis of randomized controlled trials. Am Health Syst Pharm 2017;74:904-18. [355] Chen B, Zhou Y, Yang P, Wan HW, Wu XT. Safety and efficacy of fish oil-enrich parented� ratio nutrition region for maontopese patients under geophasing major abdominal surgery: a meta-analysis of randomized controlled trials. JUN - J Parenter Enter Nutr 2010;34:387-25.

[358] Wei C, Hua J, Bin C, Klassen K. Impact of lipid emulsion containing fish oil on automes of surgical patients: systematic review of randomized controlled trials from Europe and Asia. Nutrition 2010;26:474-81. [359] Pradelli L, Mayer K. Muscaritoli M, Heller AR. n-3 fatty acid-enriched parenteral nutrition in eigensimets in elective surgical and ICU patients: a meta-analysis. Crit Care 2012;16:R184. [360] Mocellin MC, Fernandes R, Chagas TR, Trindade E. A meta-analysis of n-3 polyunsaturated fatty acids effects on circulating acute-phase protein and cytokines in gastric cancer. Clin Nutr 2018;37:840-50. [361] Pradelli L, Mayer K, Klek S, Omar Alsaleh AJ, Clark RAC, Rosenthal MD, et al. Omega-3 fatty-acid enriched parenteral nutrition in hospitalized patients: systematic review with meta-analysis and trial sequential analysis. JPEN - J Parenter Enter Nutr 2020;44:44-57. [362] Pradelli L, Mayer K, Klek S, Rosenthal MD, Povero M, Heller AR, et al. Omega-3 fatty acids in parenteral nutrition - a systematic review with network meta-analysis on clinical outcomes. Clin Nutr 2023;42:590-9. [363] Cuartero-Corbalán N, Martínez-Lozano Aranaga F, Gómez-Ramos MJ, Gómez-Sánchez MB, Avilés-Plaza FV, Núñez-Sánchez MA, et al. Comparison of n-3 PUFA-enriched, olive-oil-based lipid emulsion on oxidative stress and inflammatory response in critically ill post-surgery adults: secondary an potential analysis of a randomized controlled trial. Int J Mol Sci 2024;25:11739. [364] Lineeker M, Botea F, Aristotele Raptis D, Nicolaescu D, Limani P, Allkhanov R, et al. Perioperative omega-3 fatty acids fail to confer protection in liver surgery: results of a multicentric, double-blind, randomized controlled trial. J Hepatol 2020;72:498-505. [365] Stoppe C, Martindale RG, Klek S, Calder PC, Wischmeyer PE, Patel JJ. The role lipid of lumilisions containing omega-3 fatty acids for medical and surgical critical care patients. Crit Care 2024;28:271. [366] Suchner U, Kuhn KS, Fürst P. The scientific basis of immunonutrition, Proc Nutr Soc 2009;55:533-63. [367] Jones NE, Heyland DK. Pharmaconutrition: a new emerging paradigm. Curr Opin Gastroenteral 2008;24:24-44.75. [368] Bower RH, Cerra, Hvershadsky B, Licari JJ, Hoyt DB, Jensen GL, et al. Early enteral administration of a formula (Impact) supplemented with arginine, nucleotides, and fish oil in intensive care unit patients: results of a multi-center, prospective, randomized, clinical trial. Crit Care Med 1995;23:436-49. [369] Brown RO, Hunt H, Mowattwatt-Larssen CA, Wojtysiak SL, Henningfield MF, Kudsk KA. Comparison of specialized and standard enteral formulas in trauma patients. Pharmacotherapy 1994;14:314-20. [370] Daly JM, Lieberman MD, Goldfine J, Shou J, Weintraub F, Rosato EF, et al. Internal nutrition with supplemental arginine RNA, and omega-3 fatty acids in patients after operation: immunologic, metabolic, and clinical outcome. Surgery 1992;112:56-67. [371] Gianotti L, Braga M, Vignali A, Balzano G, Cerbi A, Bisagni P, et al. Effect of route of delivery and formulation of postoperative nutritional support in patients undergoing major operations for malignant neoplasms. Arch Surg 1997;132:1222-9. discussion 9-30. [372] Heslin MJ, Latkany L, Leung D, Brooks AD, Hochwald SN, Pisters PW, et al. A prospective, randomized trial of early enteral feeding after resection of upper gastrointestinal malignancy. Ann Surg 1997;226:567-77. discussion 77-80. [373] Klek S, Kulig J, Sierzegan M, Szczepanek K, Szybinski P, Scislo L, et al. Standard immunodulating enteral nutrition in patients after extended gastrointestinal gastrointestinal surgery-a prospective, randomized, controlled clinical trial. Clin Nutr 2008;27:504-12. [374] Kudsk KA, Minard G, Croce MA, Brown RO, Lowrey TS, Pritchard FE, et al. A randomized trial of nitrogenous enteral diets after severe trauma. An immune-enhancing diet reduces septic complications. Ann Surg 1996;224:531-40. discussion 40-3. [375] Mendez C, Jurkovich J, Garcia I, Davis D, Parker A, Maier RV. Effects of an immune-enhancing diet in critically injured patients. J Trauma 1997;42:933-40. discussion 40-1. [376] Moore FA, Moore EE, Kudsk KA, Brown RO, Bower RH, Koruda MJ, et al. Clinical benefits of an immune-enhancing diet for early postinjury enteral feeding. J Trauma 1994;37:607-15. [377] Senkal M, Mumme A, Eickhoff U, Geier B, Spath G, Wulfert D, et al. Early postoperative enteral immunonutrition: clinical outcome and cost-comparison analysis in surgical patients. Crit Care Med 1997;25:1489-96. [378] Snyderman CH, Kachman K, Molseed L, Wagner R, D'Amico F, Bumpous J, et al. et al. Reduced postoperative infections with an immune-enhancing nutri- tional supplement. Laryngoscope 1999;109:915-21. [379] Weimann A, Bastian L, Bischoff WE, Grotz M, Hansel M, Lotz J, et al. Influence of arginine, omega-3 fatty acids and nucleotide-supplemented enteral support on systemic inflammatory response syndrome and multiple organ failure in patients after severe trauma. Nutrition 1998;14:165-725. [380] Song GM, Liu XL, Bian Ww, Wu J, Deng YH, Zhang H, et al. Systematic review with network meta-analysis: comparative efficacy of different enteral immunonutrition formulas in patients underwent gastrectomy. Oncotarget 2017;8:23736-88. [381] Beale RJ, Bryg DJ, Bihari DJ. Immunonutrition in the critically ill: a systematic review of clinical outcome. Crit Care Med 1999;27:2799-805. [382] Cerantola Y, Hubner M, Grass F, Demartines N, Schafer M. Immunonutrition in gastrointestinal surgery. Br J Surg 2011;98:37-48.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[383] Drover JW, Dhaliwal R, Weitzel L, Wischmeyer PE, Ochoa JB, Heyland DK. Perioperative use of arginine-supplemented diets: a systematic review of the evidence. J Am Coll Surg 2011;212:385-99. 99 e1. Heyland DK, Novak F, Drover JW, Jain M, Su X, Suchner U. Should immunonutition become routine in critically ill patients? A systematic review of the evidence. JAMA 2001:286:944-53. [385] Heys SD, Walker LG, Smith I, Eremin O.�eral nutritional supplementation with key nutrients in patients with critical illness and cancer: a meta-analysis of randomized controlled clinical trials. Ann Surg 1999;229:467-77. [386] Waitzberg DL, Saito H, Plank LD, Jamieson GG, Jagannath P, Hwang TL, et al. Postsurgical infections are reduced with specialized nutrition support. World J Surg 2006:30:1592-604. [387] Marik PE, Zaloga GP. Immunonutrition in high-risk surgical patients: a systematic review and analysis of the literature. JUPen - J Penter Enter Nutr 2010:34:37-88. [388] Marimuthu K, Varadhan KK, Jungvissant Q, Lobo DN A. meta-analysis of the effect of combinations of immune modulating nutrients on outcome in patients undergoing major open gastrointestinal surgery. Ann Surg 2012:255:1060-8. [389] Monte JC, Zarazag A. Lopez-Martinez J, Urrutia G. Roque M, Blesa AL, et al. Immunonutrition in the intensive care unit. A systematic review and consensus statement. Clin Nutr 2003;22:221-33. [390] Stableforth WD, Thomas S, Lewis SJ. A systematic review of the rule of immunonutrition in patients undergoing surgery for head and neck cancer. Int J Oral Maxilofacv Surg 2009:38:103-10. 1911 [391] Wilhelm SM, Kale-Pradhan PB. Combination of arginine and omega-3 fatty acids external nutrition in critically ill and surgical patients: a meta-analysis. Expet Rev Clin Pharmacol 2010;3:459-69. [392] Zhang Y, Gu Y, Guo T, Li Y, Cai H. Periperative immunonutrition for gastrointestinal cancer: a systematic review of randomized controlled trials. Surg Oncol 2012:21:87-95. [393] Osland E, Hossain MB, Khan S, Memon MA. Effect of timing of pharmaconutrition (immunonutrition) administration on outcomes of elective surgery for gastrointestinal malignancies: a systematic review and meta-analysis. JUPen J - Penter Enter Nutr 2014:38:53-69. [394] Song GM, Tian X, Liang H, Yi LJ, Zhou JG, Zeng Z, et al. Role of internal immunonutrition in patients undergoing surgery for gastric cancer: a systematic review and meta-analysis of randomized controlled trials. Medicine (Baltim) 2015:94:e1311. [395] Wong CS, Aly EH. The effects of external immunonutrition in upper gastrointestinal surgery: a systematic review and meta-analysis. Int J Surg 2016;29:137-50. [396] Braga M, Gianlob A, Vignali A, Mari G, Gentilini O, et al. Peroperative immunonutrition in patients undergoing cancer surgery: results of a randomized double-blind phase 3 trial. Arch Surg 1999;134:428-33. [397] Braga M, Gianlob A, Vignali A, Carlo VD. Preoperative oral arginine and n3 fatty acid supplementation improves the immunometabolic host response and outcome after colorectal resection for cancer. Surgery 2002;132:805-14. [398] Senkal M, Zumtobel V, Bauer KH, Marpe B, Wolfram G, Frei A, et al. Outcome and cost-effectiveness of perioperative external immunituation in patients undergoing elective upper gastrointestinal tract surgery: a prospective randomized study. Arch Surg 1999;134:1309-16. [399] Tepaske R, Te Velthuis H, Uedamens van Staaten HM, Heisterkamp SH, Van Deventer SJ, Ince C, et al. Effect of preoperative oral immune-enhancing nutritional supplement on patients at high risk of infection after cardiac surgery: a randomised placebo-controlled trial. Lancet 2001;358:696-701. [400] Braga M, Gianlob A, Nespoli L, Radaelli G, Di Carlo V. Nutritional approach in malnourished surgical patients: a prospective randomized study. Arch Surg 1999;2020:137:174-80. [401] Klek S, Szybinski P, Szczepanek K. Perioperative immunonutrition in surgical cancer patients: a summary of a decade of research. World J Surg 2014:38:803-12. [402] Achilli P, Mazzola M, Bertoglio CL, Magistro C, Origi M, Carnevali P, et al. Preoperative immunonutrition in frail patients with colorectal cancer: an intervention to improve postoperative outcomes. Int J Colorectal Dis 2020;35:19-27. [403] Thorblade LV, Vhargese Jr TK, Shi X, Johnson Ek, Bastawrous A. Billingham RP, et al. Preoperative immunonutrition and elective colorectal resection outcomes. Dis Colon Rectum 2017;60:68-75. [404] Nakakima Y, Yokoyama V, Inoue T, Nagaya M, Mizuno Y, Kadono I, et al. Clinical benefit of preoperative exercise and nutritional therapy for patients undergoing hepato-pancreato-biliary surgeries for malignancy. Ann Surg Oncol 2019;26:264-72. [405] Challine A, Rives-Lange C. Danoussou D, Katshaisan S. Alt Boudaoud A. Gaujost, 5 et al. Impedal and oral immunonutition on postoperative morbidity in digestive oncologic surgery: a nation-wide cohort study. Ann Surg 2021;773:725-31. [406] Kelley KE Fjardo AD, Grassne NM, Harmon CA, Pawlecki K, Sieber M, et al. Impact of a novel preoperative patient-centered surgical wellness program. Ann Surg 2018:268:650-6. [407] Hubner M, Cerantoy A, Grass F, Bertrand PC, Schafer M, Demartines N. Preoperative immunonutrition in patients at nutritional risk: results of a double-blinded randomized clinical trial. Eur J Clin Nutr 2012;66:850-5.

[408] Giger-Pabst U, Lange J, Maurer C, Bucher C, Schreiber V, Schlumpf R, et al. Short-term preoperative supplementation of an immunoenriched diet does not improve clinical outcome in well-nourished patients undergoing abdominal cancer surgery. Nutrition 2013; 29:724–9. [409] Hegazi RA, Hustead DS, Evans DC. Preoperative standard oral nutrition supplements vs immunontrition: results of a systematic review and meta-analysis. J Am Coll Surg 2014;219:1078–87. [410] Burden S, Todd C, Hill J, Lal S. Pre-operative nutrition support in patients undergoing gastrointestinal surgery. Cochrane Database Syst Rev 2012;11: CD008879. [411] Yu K, Zheng X, Wang C, Liu M, Li Y, Yu P, et al. Immunontrution vs standard nutrition for cancer patients: a systematic review and meta-analysis (Part 1): J PEN- J Parenter Enter Nutr 2020;44:742–67. [42] Adiamah A, Skorepa We, Weimann A, Lobo DN. The impact of preoperative immune modulating nutrition on outcomes in patients undergoing surgery for gastrointestinal cancer: and a systematic review and meta-analysis. Ann Surg 2019;270:247–56. [431] Buzquurz F, Bojesen RD, Grube C, Madsen MT, Gogenur I. Impact of oral preoperative and periodic operative immunontrition on postoperative infection and mortality in patients undergoing cancer surgery: systematic review and meta-analysis with trial sequential analysis. BJS Open 2020;4: 764–75. [441] Shen J, Dai S, Li Z. Dai W, Hong J, Huang J, et al. Effect of enteral immunontrition in patients undergoing surgery for gastrointestinal cancer: an updated systematic review and meta-analysis. Front Nutr 2022;9:941975. [451] Lee SY, Lee J, Park HM, Kim CH, Kim HR. Impact of preoperative immunontrition in patients of outcomes of colon cancer surgery: results from a randomized controlled trial. Ann Surg 2023;277:381–6. [461] Zhang X, Chen X, Yang J, Hu Y, Li K. Effects of nutritional support on the clinical outcomes of well-nourished patients with cancer: a meta-analysis. Eur J Clin Nutr 2020;74:1389–400. [471] Howes N, Lewis SJ, Immunontrition for patients undergoing surgery for head and neck cancer. Cochrane Database Syst Rev 2018;8: CD010954. [481] Deftereos L, Kiss N, Isenering E, Carter VM, Yeung JM. A systematic review of the effect of preoperative nutrition support on nutritional status and treatment outcomes in upper gastrointestinal cancer resection. Eur J Surg Oncol 2020;46:1423–34. [49] Qiang H, Hang L, Shui SY. The curative effect of early use of enteral immunontrition in postoperative gastric cancer: a meta-analysis. Minerva Gastroenterol Dietol 2017;63:285–92. [413] Cheng V, Zhang J, Zhang U, Wu J Zhan Z. Enteral immunontrition versus enteral nutrition for gastric cancer patients undergoing a total gastrectomy: a systematic review and meta-analysis. BMC Gastroenterol 2018;18:11. [421] Li XK, Zhou H, Xu Y, Long ZZ, Wu WJ, Luo J, et al. Enteral immunontrition versus enteral nutrition for patients undergoing oesophagectomy: a systematic review and meta-analysis. Interact Cardiovasc Thorac Surg 2020;30:854–62. [442] Mingliang F, Huizhen W, Yongxiang L. Perioperative immunontrition in esophageal cancer patients undergoing esophagectomy: the first meta-analysis of randomized clinical trials. Dis Asphagus 2020;33:20:32:111. [423] Zhang C, Chen B, Jiao A, Li F, Wang B, Sun N, et al. The benefit of immunontrition in patients undergoing hepatectomy: a systematic review and meta-analysis. A onlogmatie review and meta-analysis. A onlogmatie review and meta-analysis of randomized controlled trials. Ann Nutr Metab 2020;76:375–86. [442] Wong F, Chen Z, Park H, May Z, St. Bautim D, Gastro, 2023;439–6414. [452] Wong G, Praseedom R, Liu SS. Perioperative immunontrition in hepatocry: a systematic review and meta-analysis. Ann Hepatobiliary Pan-creat Surg 2020;24:396–414. [464] Guan H, Chen X, Huang Q. Effects of enteral immunontrition in patients undergoing pancreatic produodenectomy: a meta-analysis of randomized controlled trials. Ann Nutr Metab 2019;74:53–61. [472] Yang PA, Chen YC, Tiong C. Immunontrution in patients with pancreatic cancer under Sorging surgical intervention: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2020;12:2798. [482] Moya P, Sorano-Irigaray L, Ramirez JM, Garcea A, Blasco O, Blanco FJ, et al. Perioperative standard solution supplements versus immunontrition in patients undergoing colorectal resection in an Enhanced Recovery (ERAS) protocol: a multicenter randomized clinical trial (SONVI Study). Medicine (Baltim) (2016;95:8724, 44. [429] Slim K, Badon F, Vacheron CH, Occean BV, Dziri C, Chambrier C. Umbrella review of the efficacy of perioperative immunontrition in visceral surp E202;48:99–108. [430] Sowerbutts AM, Burden S, Sremanakova J, French C, Knight SR, Harrison EM. Preoperative nutrition therapy in people undergoing gastrointestinal surgery. Ocrachy Database Syst Rev 2024;4:CD008879. [431] Khan A, Wong J, Riedel B, Laing E, Beaumont A, Kong J, et al. The impact of peri-operative enteral immunontrition on post-operative complications in gastrointestinal cancer surgery: a meta-analysis. Ann Surg Oncol 2023;30:3619–31. [432] Matsui R, Sagawa M, Sano A, Sakai M, Hiraoka SI, Tabel I, et al. Impact of perioperative immunontrition on postoperative outcomes for patients

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

undergoing head and neck or gastrointestinal cancer surgeries: a systematic review and meta-analysis of randomized controlled trials. Ann Surg 2024;279:419-28. [433] Zhou Y. Li IT, Yang ZL, Tan ZM, Yang CF. Wang Z. The effect of perioperative immunonutition on patients undergoing esophageomy: a systematic review and updated meta-analysis. Nutr Hosp 2023;40:839-47. [434] Yu J. Yuan A. Liu Q, Wang W, Sun Y. Li Z. et al. Effect of preoperative immunonutition on postoperative short-term clinical outcomes in patients with gastric cancer cachexia: a prospective randomized controlled trial. World J Surg Oncol 2024;22:101. [435] Zhang G, Zhao B, Deng T, He X, Chen Y, Zhong C, et al. Impact of perioperative immunonutition on postoperative outcomes in pancreaticoduodenectomy: a systematic review and meta-analysis of randomized controlled trials. BMC Gastroenterol 2024;24:412. [436] Corviveau, J: St-Jacques M, Yeung S, Carl F, Liberman AS, Watson D, et al. Co-developed logic model for surgical prehabilitation in an acute care setting: a qualitative study of stakeholders' perspectives. Ann Nutr Metab 2025;8: 1-17. [437] Wong CS, Zaman S, Siddiraju K, Sellvaraj A, Ghattas T, Tryliskyy Y. Effects of external immunonutition in laparicoagc versus open resections in colorectal cancer surgery: a meta-analysis of randomised controlled trials. Eur J Surg Oncol 2025;51:109488. [438] Stippler D, Bode V, Fischer M, Kollex K, Rohde E, Tisowsky B, et al. Proposal for a new principable categorization from food for food is important purposes - enteral nutritional products. Clin Nutr ESPEN 2015;10:e219-23. [439] Benavides-Buleje JA, Fernández-Fernández PV, Ruiz-Ocar E, Solanena Buo A, Parra-Baños PA, Martínez-Torres B, et al. Postoperative diet with an oligomeric hyperproteic normocaloric supplement versus a supplement with immunonutrients in colorectal cancer surgery: results of a multi-center, double-blind, randomized clinical trial. Nutrients 2022;14:3062. [440] Kinross JM, Markar S, Karthikesalingam A, Chow A, Penney N, Silk D, et al. A meta-analysis of probiotic and symbiotic use in elective surgery: does nutrition modulation of the gut microbiome improve clinical outcome? JPEN - J Parenter Enter Nutr 2013;37:243-53. [44� CuJ, Dew G, Tong Y, Jing R, Liu J. The effects of probiotics in early整合 related controlled trials. JPEN - J Parenter Enter Nutr 2013;37:310-7. [442] Falco de Arruda IS, de Aguilar-Nascimento JE. Benefits of early enteral nutrition with glutamine and probiotics in brain injury patients. Clin Sci (Lond) 2004;106:287-92. [443] Chowdhury AH, Adiamah A, Kushari A, Varadha H, KKrznarz, Kulkarni AD, et al. Perioperative probiotics or bibliots in adulti-in going elective abdominal surgery: a systematic review and meta-analysis of randomized controlled trials. Ann Surg 2020;271:1036-47. [444] Kotzampassi K, Giamarellos-Bourboulis EJ, Voudouris A, Kazamias P, Eleftheriadis E. Benefits of a symbiotic formula (Synbiotic200Forte) in critically ill trauma patients: early results of a randomized controlled trial. World J Surg 2006;30:1848-55. [445] Kanazwa H, Nagino M, Kamiya S, Komatsu S, Mayumi T, Takagi K, et al. Synbiotics reduce postoperative infectious complications: a randomized controlled trial in biliary cancer patients undergoing hepatectomyy. Langenbecks Arch Surg 2005;390:104-13. [446] Rayes N, Seehofer D, Theruvath T, Schiller RA, Langrehr JM, Jones S, et al. Supply of pre- and probiotics reduces bacterial infection rates after liver transplantation a randomized, double-blind trial. Am J Transplant 2005;5: 125-30. [447] Rayes N, Pilarski T, Stockmann M, Bengmark S, Neuhaus P, Seehofer D. Effect of pre- and probiotics on liver regeneration after resection: a randomised, double-blind pilot study. Benef Microbes 2012;3:237-44. [448] Rayes N, Seehofer D, Theruvath T, Mogl M, Langrehr JM, Nussler NC, et al. Effect of enteral nutrition and symbiotics on bacterial infection rates after pylorus-preserving panzeroduodenotency: a randomized, double-blind trial. Ann Surg 2007;246:36-41. [449] Sugawara G, Nagino M, Nishio H, Ebata T, Takagi K, Ashara T, et al. Perioperative symbiotic treatment to prevent postoperative infectious complications in biliary cancer surgery: a randomized controlled trial. Ann Surg 2006;244:706-14. [450] Usami M, Miyoshi M, Kanbara Y, Aoyama M, Sakaki H, Shuno K, et al. Effects of noniacus treatment in infectious complications, intestinal integrity, and fecal flora and organic acids in hepatic surgery with or without cirrhosis. JPEN - J Penter Enter Nutr 2011;35:317-28. [451] Grat M, Wronka M, Lewandowski Z. Grat K, Krasnodebski M, Stypulkowski J, et al. Effects of continuous use of probiotics before liver transplantation: a randomized, double-blind, placebo-controlled trial. Clin Nutr 2017;36:1530-9. [454] Liu Z, Li C, Huang M, Tong C, Zhang X Wang, L et al. Positive regulatory effects of perioperative probiotic treatment on postoperative liver liver complications after colorectal liver metastases surgery: a double center and double-blind randomized clinical trial BMC Gastroenterol 2015;15:134. [453] Lida H, Sasaki M, Maehira H, Mori H, Yasukawa D, Takebayashi K, et al. The effect of preoperative symbiotic treatment to prevent surgical-site-infection in paing resection. J Clin Biochem Nutr 2020;66:67-73. [454] Besselink MGH, van Santvoort HC, Buskans E, Boermeester MA, van Goor H, Timmman HM, et al. Probiotic phy��laxis in predicted severe acute

pancreatitis: a randomised, double-blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double-blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double-blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double-blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double-blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double blind, placebo-controlled trial. Lancet 2008;37:651-95; 69-97; Pranaticmatis: a randomised, double black, and other patients with a non-adromised, obliere di nutrient nutrition in patients with colorecty; non-adromised, obliere di nutrient nutrition in patients with colorecty; non-adromised, obliere di nutrient nutrition in patients with colorecty; non-adromised, obliere di nutrient nutrition in patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; non-adromised, obliere di幼儿 and other patients with colorecty; no

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

undergoing major abdominal surgery: a systematic review and meta-analysis. Clin Nutr 2024;43:629-48. [479] Gillis C, Weimann A. Prehabilitation in surgery - an update with a focus on nutrition. Curr Opin Clin Nutr Metab Care 2025;28:224-34. [480] Impact of malnutrition on early outcomes after cancer surgery: an international, multicentre, prospective cohort study. Lancet Global Health 2023;11:e341-9. [481] Barberan-Garcia A, Ubre M, Roca J, Lucy AM, Burgos F, Risco R, et al. Personalised prehabilitation in high-risk patients undergoing elective major abdominal surgery: a randomized blinded controlled trial. Ann Surg 2018;267:50-6. [482] Gillis C, Fenton TR, Gramlich L, Sajobi TT, Culos-Reed SN, Bousquet-Dion G, et al. Older frail prehabilitated patients who cannot attain a 400 m-6 min walking distance before colorectal surgery suffer more postoperative complications. Eur J Surg Oncol 2021;47:87-84. [483] Berkel AEM, Bongers BC, Kotte H, Weltevreden P, de Jongh FHC, Eijsvogel MMM, et al. Effects of Community-based exercise prehabilitation for patients scheduled for colorectal surgery with high risk for postoperative complications: results of a randomized clinical trial. Ann Surg 2022;27:295e-2996. [484] Koet LL, Kraima A, Derksen I, Lamme B, Belt ETJ, van Rosmalen J, et al. Effectiveness of preoperative group education for patients with colorectal cancer: managing expectations. Support Care Cancer 2021;29:5263-71. [485] Gillis C, Hasil L, Keane C, Brassard D, Kiernan F, Bellafronte NT, et al. A multimodal prehabilitation class for Enhanced Recovery after Surgery: a programized random type 1 hybrid effectiveness-implementation trial. Br J Anaeth 2025. https://doi.org/10.1016/j.bja.2023.03.001 [Epub ahead of print]. Burden ST, Hill J, Shaffer JL, Campbell M, Todd C. An unblinded randomised controlled trial of preoperative oral supplements in colorectal cancer patients. J Hum Nutr Diet 2011;24:441-8., Darien Elharut. Zell an Prehabilitation in elective abdominal cancer surgery in older patients: systematic review and meta-analysis. BJS Open 2020;4:1022-41. [485] Bruns ERJ, Agillander TE, Van Den Heuvel B, Buskens CJ, Van Duivijdelijk P, Winkels RM, et al. Oral nutrition as a form of pre-operative enhancement in patients undergoing surgery for colorectal cancer: a systematic review. Surg Infect 2018;19:1-10. [489] Grass F, Demartines N. Compliance with preoperative oral nutritional supplements in patients at nutritional risk: only a question of will? Eur J Clin Nutr 2015;69:525-9. [490] Nichols E, O'Hara NN, Degani Y, Sprague SA, Adachi JD, Bhandari M, et al. Patient preferences for nutritional supplementation to improve fracture healing: a discrete choice experiment. BMJ Open 2018:8:e019685. [491] Kong SH, Lee HJ, Na JR, Kim WG, Han DS, Park SH, et al. Effect of perioperative oral nutritional supplementation in mainnourished patients who undergo gastectomy: a prospective randomized trial. Surgery 2018;164:1263-70. [492] Deftereo I, Yeung JM, Arslan J, Carter VM, Isensring E, Kiss N, et al. Preoperative nutrition intervention in patients undergoing resection for upper gastrointestinal cancer: results of the multi-centre NOURISH point prevalence study. Nutrients 2021;13:3205. [493] lakanurak N, Gramlich L, The role of preoperative parental nutrition. Nutrients 2020;12:1320. [494] Hill GL Impact of nutritional support on the clinical outcome of the surgical patient. Clin Nutr 1994;13:331-40., Bursi T, Buowmy C, Jeeebhoy KN. Effect of feeding malnourished patients for 1 mo on mitochondrial complex I activity and nutritional assessment measurements. Am J Clin Nutr 2004;79:787-94. [494] Huang ZX, Zhang HH, Zhang WT, Shi MM, Ren JH, Xu LB, et al. Effect of short-term preoperative parental nutrition support for gastric cancer patients with sarcopenia: a propensity score matching analysis. J Gastrointest Surg 2022;26:1362-72. [497] MClave SA, Martindale RG, Vanek VW, McCarthy M, Roberts P, Taylor B, et al. Guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient: society of Critical Care Medicine (SCM) and American Society for Parenteral and External Nutrition (A.S.P.E. N.J. JPEN - J Parenter Enter Nutr 2009;33:277-316. [498] Constansia RDN, Hentzen J, Hogenbirk RNM, van der Plw Y, Campans-Kuijpers MJE, Buis Cl, et al. Actual postoperative protein and calorie intake in patients undergoing major open abdominal cancer surgery: a prospective, observational cohort study. Nut Clin Pract 2022;37:183-97. [499] Hur H, Kim SG, Shim JH, Song KY, Kim W, Park CH, et al. Effect of early oral feeding after gastric cancer surgery: a methodized clinical trial. Surgery 2011;149:561-8. [500] Seven H, Calis AB, Turgut S. A randomized controlled trial of early oral feeding in laryngectomized patients. Laryngoscope 2003;113:1076-9. [501] Perel P, Yanagawa T, Bunn F, Roberts I, Wentze R, Pierto A. Nutritional support for head-injured patients. Cochrane Database Syst Rev 2006;4:CD01530. [502] Sousa AA, Porcaro-Salles JM, Soares JM, Meyer de Moraes G, Souza Silva G, Abreu Sepulri c, et al. Tolerance of early oral feeding in patients subjected to total larynectomy. Head Neck 2016;38(Suppl 1):E643-8.

[503] Bollschweiler E. Schroder W, Holscher AH, Siewert JR. Preoperative risk analysis in patients with adenocarcinoma or squamous cell carcinoma of the oesophagus. Br J Surg 2000;87:1106–10. [504] Saito T, Kuwahara A, Shigemitsu Y, Kinoshita T, Shimoda K, Miyahara M, et al. Factors related to malnutrition in patients with esophageal cancer. Nutrition 1991;7:117–21. [505] Takagi K, Yamamori H, Morishima Y, Toyoda Y, Nakajima N, Tashiro T. Preoperative suppression: its relationship with high morbidity and mortality in patients receiving thoracic esophagectomy. Nutrition 2001;17:13–7. [506] Klek S, Sziergaeg M, Szybinski P, Szczepanek K, Scislo L, Walewska E, et al. Perioperative nutrition in malnourished surgical cancer patients - a prospective, randomized, controlled clinical trial. Clin Nutr 2011;30:708–13. [507] Williams DGA, Ohnuma T, Krishnamoorthy V, Raghunathan K, Sulo S, Cassady BA, et al. Postoperative utilization of oral nutrition supplements in surgical patients in US Hospitals. JPEN - J Parenter Enter Nutr 2021;45: 596–606. [508] Kompan L, Kremzar B, Gadzijev E, Prosek M. Effects of early enteral nutri- on in intestinal permeability and the development of multiple organ failure after multiple injury. Intensive Care Med 1999;25:157–61. [509] Eleftheriadis K, Davai T. Do patients fed enterally post-gastrointestinal surgery experience more complications when fed a fiber-enriched feed compared with a standard feed? A systematic review. Nutr Clin Pract 2022;37:797–810. [510] Delany HM, Carnevale N, Garvey JW, Moss GM. Postoperative nutritional support using needle catheter feeding jejunostomy. Ann Surg 1977;186: 165–70. [511] Daly JM, Bonau R, Stofberg P, Bloch A, Jeevanandam M, Morse M. Immediate postoperative jejunostomy feeding. Clinical and metabolic results in a prospective trial. Am J Surg 1987;153:198–206. [512] Kemen M, Senkal M, Homann HH, Mumme A, Dauphin AK, Baier J, et al. Early postoperative enteral nutrition with arginine-omega-3 fatty acids and ribonucleic acid-supplemented diet versus placebo in cancer patients: an immunologic evaluation of Impact. Crit Care Med 1995;23:652–9. [513] Gabor S, Renner H, Matzien R, Latzenoehar B, Lindenmann J. Sankin O, et al. Early ental feeding compared with parenteral nutrition after oesophageal or oesophagogastric resection and reconstruction. Br J Nutr 2005;93: 509–13. [514] Braga M, Gianotti L, Gesentilini O, Liotta S, Di Carlo V. Feeding the gut early after digestive surgery: results of a nine-year experience. Clin Nutr 2002;21:59–65. [515] Gopta V, Benefits versus risks: a prospective audit. Feeding jejunostomy during esophagectomy. World J Surg 2009;33:1432–8. [516] Senkal M, Koch J. Hummel T, Zumtobel V. Laparoscopic needle catheter jejunostomy: modification of the technique and outcome results. Surg endocm 2024;18:37–90. [517] Obida LF, Salimi T, Ferri F, Henrique J, Lo Menzo E, Szomstein S, et al. Complications of feeding jejunostomy placement: a single-institution experience. Surg Endosc 2021;35:3989–97. [518] Pu XS, Bao T, Wang YJ, Li KK, Yang Q, He XD, et al. Laparoscopic jejunostomy during McKeown minimally invasive esophagectomy: a propensity score analysis. Surg Endosc 2025;39:1801–10. [519] Biffi R, Lotti M, Cenciarelli S, Luca F, Pozzi S, Zambelli M, et al. Complications and long-term outcome of 80 oncology patients undergoing needle catheter jejunostomy treatment for early postoperative enteral feeding. Clin Nutr 2000;19:277–9. [520] Bruin ME, Obertop H, Ong GL. Acute abdominal pain due to last peropative elemental feeding by needle jejunostomy. Surg Gynecol Obstet 1983;157:40–2. [531] Chin XF, Townsend S, Wong W, Miller GV. A prospective cohort study of feeding needle netearjostomy in an upper gastrointestinal surgical unit. Clin Nutr 2004;23:691–6. [542] Eddy VA, Snell JE, Morris Jr JA. Analysis of complications and long-term outcome of trauma patients with needle catheter jejunostomy. Am Surg 1996;62:40–4. [553] Myers Jc, Page CP, Stewart RM, Schwesinger WH, Sirinek KR, Aust JB. Complications of needle catheter jejunostomy in 2,022 consecutive applications. Am J Surg 1995;17:047–50. discussion 50–1. [542] Ramamurthy A, Negi SS., Chaudhary A. Prophylactic tube jejunostomy: a worthwhile undertaking. Surg Today 2008;38:420–4. [552] Sarr MG. Appropriate use, complications and advantages demonstrated in 500 consecutive needle catheter jejunostomys. Br J Surg 1999;86:557–61. [554] SchattenkRe, M. Hubringen H, Van Rooyen W, van Houten H. Early postoperative enteral feeding by a needle catheter jejunostomy after feeding in oesophagects and reconstructions for cancer. Clin Nutr 1984;37:4–9. [567] Sica GS, Jumardran V, Wheeler J, Soin B, Maynard N. Needle catheter jejunostomy at esophagectomy for cancer. J Surg Oncol 2005;91:276–9. [588] Strickland GF, Greene FL. Needle-catheter jejunostomy for postoperative nutritional support. South Med J 1986;79:1389–92. [598] Vestweber KH, Epasch E, Paul A, Bode C, Troidl H. Fine-needle catheter jejunostomy. Z Gastroenterol 1989;27(Suppl 2):69–72. [590] Gerritsen A, Besselink MG, Cieslak KP, Vriens MR, Steenhagen E, van Hilgersberg R, et al. Efficacy and complications of nasojejunal,

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

jejunostomy and parenteral feeding after pancreaticododenectomy. J Gastrointest Surg 2012;16:1144-51. [531] Yermilov I, Jain S, Sekeris E, Bentrem DJ, Hines OJ, Reher HA, et al. Utilization of parenteral nutrition following pancreaticododenectomy: is routine jeunostomy use placement warranted? Dig Dis Sci 2009;54:1582-8. [532] Dann GC, Squires IlIMH, Postlewait LM, Kooby DA, Poultsides GA, Weber SM, et al. An assessment of feeding jejunostomy tube placement at the time of resection for gastric adenocarcinoma: a seven-institution analysis of 837 patients from the US gastric cancer collaborative. J Surg oncol 2015;112:195-202. [533] Koteraazwa Y, Oshikiri T, Hasegawa H, Yamamoto M, Kanaji S, Yamashita K, et al. Routine placement of feeding jejunostomy tube during esophagectomy increases postoperative complications and does not improve postoperative malnutrition. Dis Esophagus 2020;33:doz021. [546] Agarwal I, Dash NR, Pal S, Madhusudhan KS, Mani V. Single-center randomized trial comparing feeding jejunostomy with nasojeijal tube placement in patients undergoing grations transhiatal esophagectomy post-neoadjuvant therapy for esophageal cancer. J Gastrointest Cancer 2024;55:1282-90. [553] Na KJ, Kang CH, Kim YR, Kang ML Song EH, Lang E, lanj E, et al. Comparison of clinical outcomes and postoperative nutritional status between early and late oral feeding after esophagectomy: an open labeled randomized controlled trial. Ann Surg 2025;281:388-94. [567] Lih Hen, Chen Y, Dai L, Wang YY, Chen MW, LiX. Ma a meta-analysis of jejunostomy versus nasoenteral tube for enteral nutrition following esophagectomy. J Surg Res 2021;264:53-631. [573] Shen X, Zhu ZG, Li G, Alai GH, Song TN, Xu ZJ, et al. Is the routine placement of a feeding jejunostomy during esophagectomy worthwhile? a systematic review and meta-analysis. Ann Palliat Med 2021;10:4232-41. [58] Zhu X, Wu Y, Qiu Y, Jiang C, Ding Y. Comparative analysis of the efficacy and complications of nasojeunal and jeunostomy on patients undergoing pancreaticododenectomy. JPF - Jenter Enter Nutr 2014;38:996-1002. [59] Kang KY, Dong L, Ge Y, An Y. GY. Short-term clinical outcomes of enteral nutrition versus parenteral nutrition after surgery for pancreatic cancer: a meta-analysis. Transl Cancer Res 2019;8:1403-11. [514] Cai J, Yang G, Tao H, Yan Y, Lin L, Wang X. A meta-analysis of the effect of early enteral nutrition versus total parenteral nutrition on patients after pancreaticododenectomy. JHP (Oxford) 2020;22:20-5. [52] Markides G, Al-Khaffaf B, Vickers J. Nutritional access routes following oesophagectomy—a systematic review. Eur J Clin Nutr 2011;65:565-73. [54] Braga, Capetti G, Pecorelli N, Balzano G, Doglioni C, Ariotti R, et al. A proagistic score to predict major complications after pancreaticododenectomy. Ann Surg 2011;254:702-7.; discussion 7-8. [543] National Collaborating Centre for Acute Care. Nutrition support for adults: oral nutrition support, enteral tube feeding and parenteral nutrition. London: National Institute for Health and Care Excellence (NICE); 2017. Available at: https://www.nice.org.uk/guidance/cg32/evidence/full-guideline-194889835. [544] Da Silva JV, Seres DS, Sabino K, Adams SC, Berdahl GJ, Citty SW, et al. ASPEN consensus recommendations for refeeding syndrome. Nutrin Pract 2020;35:178-95. [545] Berger MM, Shenkin A, Schweinlin A, Amrein K, Augsburger M, Biesalski HK, et al. ESPEN micronutrient guideline. Clin Nutr 2022;41:1357-424. [546] Iöser C, Asch G, Hebuterne X, Mathus-Vliegen E, Muscaritoli M, Niv Y, et al. ESPEN guidelines on artificial enteral nutrition-percutaneous endoscopic gastrostomy (PEG). Clin Nutr 2005;24:848-61. [547] Bischoff SC, Austin P, Boeykens K, Chourdakis M, Cuerda C. Jonkers-Schuitema C, et al. ESPEN guideline on home enteral nutrition. Clin Nutr 2020;39:5-22. [548] Haverkort EB, Binnekade JM, de Haan RJ, Busch OR, van Berge Henegouwen MI, Gouma DJ. Suboptimal intake of nutrients after esophagectomy with gastric tube reconstruction. J Acad Nutr Diet 2021;12:1080-7. [549] Lidoriki I, Schizas D, Mylonas K, Frountzas M, Mastoraki A, Pikoul E, et al. Oral nutritional supplementation following upper gastrointestinal cancer surgery: a prospective analysis exploring potential barriers to compliance. J Am Coll Nutr 2020;39:650-6. [550] Bae JM, Park JW, Yang HK, Kim JP. Nutritional status of gastric cancer patients after total gastrectomy. World J Surg 1998;22:254-60. discussion 60-1. [551] Ouattara D, M'Journo XB, Londouna A, Trousse D, Dahan L, Doddodi C, et al. Body mass index kinetics and risk factors of malnutrition one year after radical esophagectomy for cancer. Eur J Cardio Thorac Surg 2012;41:1089-93. [552] Baker M, Halliday V, Williams RN, Bowrey DJ. A systematic review of the nutritional consequences of esophagectomy for cancer. Eur J Cardio Thorac Surg 2012;41:1089-93. [553] Peterson SJ, Tsai AA, Scala CM, Sowa DC, Shean PM, Braunschweig CL. Adequacy of oral intake in critically ill patients 1 week after extubation. J Am Diet Assoc 2010;110:427-33. [554] Rowley A, Adiamah A, Kushair A, Lewis J, Solo D. The effect of post-discharge oral nutritional supplements on outcomes after gastrointestinal surgery: a systematic review and meta-analysis. Clin Nutr 2023;42:1185-2010. [555] Ulander K, Jeppsson B, Grahn G. Postoperative energy intake in patients after colorectal cancer surgery. Scand J Caring Sci 1998;12:131-8.

[556] Grass F, Benoit M, Coti Bertrand P, Sola J, Schäfer M, Demartines N, et al. National status deteriorates postoperatively despite preoperative nutritional support. Ann Nutr Metab 2016;68:291-7. [557] Henehan HM, Zaborowski A, Pmedhry S, Moore J, et al. Prospective study of malabsorption and malnutrition after esophageal and gastric cancer surgery. Ann Surg 2015;262:803-7. discussion 7-8. [558] Hatao F, Chen KY, Wu Jm, Wang MY, Aikou S, Onoyama H, et al. Randomized controlled clinical assessing the effects of oral nutritional supplements in postoperative gastric cancer patients. Langenbecks Arch Surg 2017;402:203-11. [559] Imamura H, Nishikawa K, Kishi K, Inoue K, Matsuyama J, Akamaru Y, et al. Effects of an oral elementary cancer cancer patients: a randomized controlled clinical trial. Ann Surg� 2016;23:2928-35. [560] Kimura Y, Nishikawa K, Kishi K, Inoue K, Matsuyama J, Akamaru Y, et al. Long-term effects of an oral elemental nutritional supplement on post-gastroctomy gasctroctomy body weight loss in gastric cancer patients (KSES002). Ann Gastroenterol Surg 2019;3:648-56. [561] Imamura H, Nishikawa K, Endo S, Kawase T, Kimura Y, et al. Effects of an oral elemental nutritional supplement in gastric cancer patients with adjuvant of 1 chemotherapy after gastrectomy: a multicenter, open-label, single-arm, prospective phase II study (OGSG1108). Ann Gas-Troenterol Surg 2021;5:776-84. [562] Meng Q, Tan S, Jiang Y, Han J, Xi Q, Zhuang Q, et al. Post-discharge oral nutritional supplements with dietary advice in patients at nutritional risk after surgery for gastric cancer: a randomized clinical trial. Clin Nutr 2021;40:40-6. [563] Tan S, Xi Q, Zhang Z, Yan M, Meng Q, Zhuang Q, et al. Nutritional support after hospital discharge reduces long-term mortality in patients after gastric surgery: secondary analysis of a prospective randomized trial. Nutrition 2025;129:112597. [564] Miyazaki Y, Omori T, Fujita K, Fujita J, Kawabata R, Imamura H, et al. Oral nutritional supplement versus a regular diet alone for body weight loss after gastrectomy: a phase 3, multicenter, open-label randomized controlled trial. Gastric cancer: 2021;24:1150-9. [565] Choi M, Kim J8, HH, Park E, Shim SR. Oral nutritional supplements reduce body weight loss after gastrectomy in patients with gastric cancer: a systematic review and meta-analysis of randomized controlled trials. Nutr 2023;15:3924. [566] Tan S, Meng Q, Jiang Y, Zhuang Q, Xi Q, Xu J, et al. Impact of oral nutritional supplements in post-discharge patients at nutritional risk following colorectal cancer surgery a randomised clinical trial. Clin Nutr 2021;40:47-53. [567] Wobith M, Wehle L, HaberzettI D, Acikgöz A, Weimann A. Needle catheter jejunostomy in patients undergoing surgery for upper gastrointestinal and pancreto-impact on nutritional and clinical outcome in the year and standard care after esophagectomy or total gastrectomy for cancer: report on a pilot and feasibility study. Trials 2015;16:531. [568] Chen T, Jiang W, He G. Effect of family enteral nutrition on nutritional status in elderly patients with esophageal carcinoma after minimally invasive radical surgery: a randomized trial. Ann Palliat Med 2021;10:6760-7. [567] Komatsu S, Konishi T, Matsubara D, Soga K, Shimomura K, Ikeda J, et al. Night home lateral nutrition as a novel enforced and physiologically effective nutrition therapy following total gastrectomy for gastric cancer. Sci Rep 2022;12:14922. [567] Ryan AM, Reynolds JV, Heyrne M, Moore J, Brannelly N, et al. Enteral nutrition enriched with eicosapentaenoic acid (EPA) preserves lean body mass following esophageal cancer: results of a double-blinded randomized control trial. Ann Surg 2009;249:355-63. [572] Liu L, Wang YC, Liu QW, Zhong JD, Li JB, Wu XD, et al. Home enteral nutrition after esophagectomy for esophageal cancer: a systematic review and meta-analysis. Medicine (Baltim) 2020;99:e21988. [573] Froghi F, Sanders G, Berisford R, Wheatley T, Peyser P, Rahamim J, et al. A randomised trial of post-discharge external feeding following surgical resection of an upper gastrointestinal malignancy. Clin Nutr 2017;36:1516-9. [574] Halliday V, Baker M, Thomas AL, Bowrey D. Patient and family caregivers' experiences of living with a jejunostomy feeding tube after surgery for esophagectrica cancer. JPEN - J Parenter Enter Nutr 2017;41:837-43. [575] Xueting H, Li L, Meng Y, Yuqing C, Yutong H, Lihong Q, et al. Home enteral nutrition and oral nutritional supplements in postoperative patients with upper gastrointestinal malignancy: a systematic review and meta-analysis. Chem with Weimann A. Oral nutritional supplements and enteral nutrition with with weimann A. Oral nutritional supplement of a open during the best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best year and best yea

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[579] Mechanick JL, Apovian C Brethauer S, Timothy Warvey W, Joffre AM, Kim J, et al. Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatroc procedures - 2019 update:�consored by American Association of Clinical Endocrinologists/ American College of Endocrinology, the Obesity Society, American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists. Obesity (Silver Spring) 2020:1–01–58. [580] Davey MG, Donlon NE, Fearon NM, Heneghan HM, Conneely JB. Evaluating the impact of Enhanced Recovery after Surgery protocols on surgical outcomes following bariatric surgery-a systematic review and meta-analysis of randomised clinical trials. Obes Surg 2024;34:778–89. [581] Hou J, Du R, Wang L, Wang F, Li D, Tong G, et al. The application of Enhanced Recovery after Surgery (ERAS) for patients undergoing bariatric surgery: a systematic review and meta-analysis. Obes Surg 2021;31:1221–31. [582] Edholm D. Early intake of solid food after Roux-en-Y gastric bypass and complications. A cohort study from the Scandinavian Obesity Surgery Registry. Surg.� Obes Relat Dis 2018;14:1256–60. [583] Theunissen CMJ, Maring JK, Raejmaekers NJC, Martijnse IS Langenhof BS, early postoperative progestion to solid foods is safe after Roux-en-Y gastric bypass, obes Surg 2015;26:296–302. [584] Sarwer DB, Moore RH, Spitzer JC Wadden TA, Raper SE, Williams NN. A pilot study in the绩效 e efficacy of postoperative dietary counseling to improve outcomes after bariatric surgery. Surg. Obes Relat Dis 2018; 5:61–8. [585] Garg T, Birke K, Ulysses R, Azagury D, Rivas H, Morton JM. A postoperative nutritional consult improves bariatric surgery outcomes. Surg Obes Relat Dis 2016;12:1052–6. [586] Endvelt R, Ben-Assuli O, Klain e, Zelger-Sagi S. The role of dietian follow-up in the success of bariatric surgery. Surg. Obes Relat Dis 2013;9: 963–8. [587] Moslehi N, Kamali Z, Golzarand M, Sakak FR, Mirmiran P. Association between energy and macronutrient intakes and weight change after bariatric surgery: a systematic review and meta-analysis. Obes Surg 2023;33:98–49. [588] Romeijn MM, Holthuijs DDB, Kolen AM, Janssen L, Schep G, van Delen FMH, et al. The effect of additional protein on lean body mass preservation in post-bariatric surgery patients: a systematic review. Nutr J 2021;20:27. [589] Omos MA Vazquez, MJa Goria MJ, González PP, Martinez IO. Chimeino IM, et al. Effect of parenteral nutrition nutrition status for baratric surgery for morbid obesity. JPEN – J Parenter Enter Nutr 2005;29:445–50. [590] Balteita C. Berindagoa K, Cabrera M, Palau M, Gonzales M. Management of anastotic peaks after laparoscopic gastric bypass. Obes Surg 2004;14:1299–307. [591] González R, Nberg MG, Smith CD, Baghai M, Kendrick M, Szomstein S, et al. Diagnosis and contemporary management of anastomotic leaks after gastric bypass for obesity. J am Coll Surg 2007;44:149–2097. [592] Strong AT, Fayzazade Hh, GMara G, El-Hayek K, Kroh M, Rodriguez J. Feeding the gut after revisional bariatric surgery: the fate of 126 entaal access tubes. Surg Obes Relat Dis 2018;14:986–91. [594] Bashah M, Khidin Y, Al-Matbouy M. Management of leak after sleeve gastrectomy: outcomes of 73 cases, treatment algorithm and predictors of resolution. Obes Surg 2020;30:515–20. [595] Ribeiro HS, Coury NC, de Vasconcelos Generoso S, Lima as Correia M. Energy balance and nutrition status: a prospective assessment of patients undergoing liver transplantation. Nutr Clin Pract 2020;35:126–32. [596] Plaut M, Bernal W, Dasarathy S, Merli M, Plank LD, Schutz T, et al. ESPEN guideline on clinical nutrition in liver disease. Clin Nutr 2019;38: 485–521. [597] Pironi L, Cuerda C, Jeppesen PB, Joly F, Jonkers C, KranizëZ, & et al. ESPEN guideline on chronic intestinal failure of adults - update 2023. Clin Nutr 2023;42:1940–2021. [598] Facciadori E, Sabatino A, Barazzoni R, Carrero JJ, Cupisti A, De Waele E, et al. ESPEN guideline on clinical nutrition in hospitalized patients with acute or chronic kidney disease. Clin Nutr 2021;40:1644–68. [599] Figueiredo F, Dickson ER, Pasha T, Kasparova P, Therneau T, Malinchoc M, et al. Impact of nutritional status on outcomes after liver transplantation. Transplantation 2000;70:142–3017;34:442. [599] Moukarzel AA, Najm I, Vargas J, McDarmid SV, Busuttil W, Ament ME. Effect of nutritional status on outcome of orthotopic liver transplantation in pediatric patients. Transplant Proc 1990;22:156–303. [601] Roggero P, Catalietti E Ulla, L Stulfesser S, Nebbia G, Bracaloni D, et al. Factors influencing malnutrition in children waiting for liver transplants. Am J Clin Nutr 1997;65:1852–7. [602] Selberg O, Botcher J, Tusch G, Pchímayr R, Henkel E, Muller MJ. Identification of high- and low-risk patients before liver translation: a prospective cohort study of nutritional and metabolic parameters in 150 patients. Hepatology 1997;25:652–7. [603] Harrison J, McKiernan J, Neuberger JM. A prospective study on the effect of recipient nutritional status on outcome in liver transplantation. Transpl Int 1997;10:369–74.

[604] Forli L, Pedersen J J, Bortuft O, Vatn M, Boe J. Dietary support to under-weight patients with end-stage pulmonary disease assessed for lung transplantation. Respiration 2001;68:51-7. [605] Le Cornu KA, McKiernan FJ, Kapadia SA, Neuberger JM. A prospective randomized study of preoperative nutritional supplementation in patients awaiting elective orthopic liver transplantation. Transplantation 2000;69: 1364-9. [606] Chin SE, Shepherd RW, Thomas BJ, Cleghorn GJ, Patrick MK, Wilcox JA, et al. Nutritional support in children with end-stage liver disease: a randomized crossover of trial of a branched-chain amino acid supplement. Am J Clin Nutr 1992;56:158-63. [607] Plank LD, McCall JL, Gene J, Rafique M, Gillanders LK, Mcllroy K, et al. Pre-and postoperative immunonutrition in patients undergoing liver transplantation: a pilot study of safety and efficacy. Clin Nutr 2005;24: 288-96. [608] Plank LD, Mathur S, Gane EJ, Peng SL, Gillanders LK, Mcllroy K, Chavez CP, Calder PC, McCall JL, Perioperative immunonutrition in patients undergoing liver transplantation: a randomized double-blind trial. Hepatology 2015;61: 639-47. [609] Ferreira SC, Souza NP, Amado LRN, Melo JOF, Reis IA, Anastácio LR. The effect of β-hydroxy β-methylbutyrate (HMB) with nutritional counselling on anthropometric muscle mass markers, strength, functionality, and quality of life in patients on the waiting list for liver transplantation: a double-blind study. Nutrition 2023;11:10:112021. [610] Ferreira SC, Cardoso ASR, Machado AAS, Anastácio LR. Effect of a 12-week nutritional intervention in the food intake of patients on the waiting list study. Nutrition: a secondary analysis of a randomized controlled trial. Clin Nutr 2024;43:1278-90. [611] Chapman R, Wong D, Sinclair M, Hey P, Terbah R, Gow P, et al. Reversing malnutrition and low muscle strength with targeted enteral feeding in patients awaiting liver transplantant: a randomized controlled trial. Hepatology 2024;80:1134-46. [62] Lindell S, Hansa R, Rankin M, Danielewicz R, Belzer FO, Southard JH. Donor nutritional status-a determinant of liver preservation injury. Transplantation 1996;61:239-47. [613] Hasse JM, Blue LS, Liepa GU, Goldstein RM, Jennings LW, Mor E, et al. Early enteral nutrition support in patients undergoing liver transplantation. JPEN - J Parenter Enter Nutr 1995;19:437-43. [614] Tinguely P, Morare N, Ramirez-Del Val A, Berenguer M, Niemann CU, Pollok JM, et al. Enhanced recovery after surgery programs improve short-term outcomes after liver transplantation–a systematic review and meta-analysis. Clin Analysis, Clin Transplant 2021;35:e14453. [615] Schulz RJ, Dignass A, Pascher A, Heckhausen J, Wiedenmann B, Neuhaus P, et al. New dietary concepts in small bowel transplantation. Transplant Proc 2002;34:893-55. [616] Yirui L, Yin W, Juan L, Yanpei C, The clinical effect of early enteral nutrition in liver-transplanted patients: a systematic review and meta-analysis. Clin Res Hepatol Gastroenterol 2021;45:101594. [617] EASIL Clinical Practice Guidelines on nutrition in chronic liver disease. J Hepatol 2019;70:172-93. [618] Murway M, Grogan TA, Lever J, Warty VS, Fung J, Venkataramanan R. Com- parison of retrolimus absorption in transplant patients receiving contin- uous versus interrupted enteral nutritional feeding. Ann Pharmacother 1998:32:633-6. [619] Pescovitz MD, Mehta PL, Leapman SB, Milgrom ML, Jindal RM, Filo RS. Tube J-jeunostomy in liver transplant recipients. Surgery 1995;117: 642-7. [601] Peri L, Boeykens K, Bozzetti F, Joly F, Klek S, Lal S, et al. ESPEN guideline on home parental nutrition. Clin Nutr 2020;39:1645-66. [62] Cooper TE, Scholes-Robertson N, Craig JC, Hawley CM, Howell M, Johnson DW, et al. Synibiotics, prebiotics and probiotics for solid organ transplant recipients. Cochrane Database Syst Rev 2022;9: CD014804. [62] Lei Q, Wang X, Zheng H, Bi J, Tan S, Li N. Peri-operative immunonutrition in patients undergoing liver transplantation: a meta-analysis of randomized controlled trials. Asia Pac J Clin Nutr 2015;24:583-90. [62] Li Y, Chen J, Tang Y, Lin T, Song T. Effect of pretransplant sarcopenia on patient and graft outcomes in solid organ transplant recipients: a systematic review and meta-analysis. Asian J Surg 2024;47:1723-33. [618] van Son J, Stam SP, Gomes-Neto AW, Osté MCJ, Blokzjl H, van den Berg AP, et al. Post-transplant obesity impacts long-term survival after liver trans- plantation. Metabolism 2020;106:154204. [619] Zex S, L, H, Luang Z, Fan Y, Lin T, Song T. Nonlinear relationship between body mass index and clinical outcomes after kidney transplantation: a dose-response meta-analysis of 50 observational studies. Surgery 2022;171:1396-405. [662] 2022;171:1396-405. [662] Ferreira AP, Machado MV. Impact of pretransplant frailty and sarcopenia on the post-transplant prognosis of patients with liver cirrhosis: a systematic review. Eur J Gastroenterol Hepatol 2021;33:e883-97. [667] Spillman LN, Madden AM, Richardson H, Imamura F, Jones D, Nash M, et al. Nutritional intake after liver transplant: systematic review and meta-analysis. Nutrients 2023;15:2487. [628] Anastácio LR, Ferreira IG, Ribeiro HS, Diniz KGD, Lima AS, Correia M, et al. Sarcopenia, obesity and sarcopenic obesity in liver transplantation: a body composition prospective study. Arq Bras Cir Dig 2019;32:e1434.

A. Weimann, M. Bezmarevic, M. Braga et al.

Clinical Nutrition 53 (2025) 222–261

[629] Hussaini SH, Oldroyd B, Stewart SP, Soo S, Roman F, Smith MA, et al. Effects of orthotopic liver transplantation on body composition. Liver 1998;18: 173-9. [630] Plank LD, Metzger DJ, McCall JL, Barclay KL, Gane EJ, Streat SJ, et al. Sequential changes in the metabolic response to orthotopic liver transplantation during the first year after surgery. Ann Surg 2001;234:245-55. [631] Wołoszyk P, Malgorzewicz S, Chamienia A, Dębska-Ślizień A. Obesity after successful kidney transplantation. Transplant Proc 2020;52:2352-6.

[632] Chierici A, Alromayan M, De Fatico S, Drai C, Vinci D, Anty R, et al. Is bariatric surgery safer before, during, or after liver transplantation? A systematic review and meta-analysis. J Liver Transplant 2023;9: 100139.

[633] Fernando S, Varma J, Dengu F, Menon V, Malik S, O'Callaghan J. Bariatric surgery improves access to renal transplantation and is safe in renal failure as well as after transplantation: a systematic review and meta-analysis. Transplant Rev 2023;37:100777.

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