Clinical Nutrition in Surgery: Top Highlights from the ESPEN 2025 Guidelines

Understanding the special nutritional needs of patients undergoing major procedures, such as surgery, and those who experience severe postoperative complications, the European Society for Clinical Nutrition and Metabolism (ESPEN) has published its updated, comprehensive guidance on perioperative nutritional care. The guideline was published online in the September issue of Clinical Nutrition.

This guideline updates the previous 2017 ESPEN practical guideline and integrates nutritional care into the established Enhanced Recovery After Surgery (ERAS) concept. It aims to cover the special nutritional needs of patients undergoing major procedures, such as cancer surgery, and those who experience severe postoperative complications.

Top highlights from the ESPEN guideline update

The guidelines present 44 recommendations for clinical practice, along with the degree of grade recommendation. The grades of recommendation were decided according to the level of evidence assigned. The guideline applies the GRADE methodology for the grading and assessment of new literature. The strength of these recommendations is reflected by mandated wording: Grade A ("shall") denotes a strong recommendation, Grade B ("should") signifies an intermediate recommendation, Grade 0 ("can" or "may") indicates a weak recommendation, and GPP (Good Practice Points) are based on expert consensus due to a lack of supportive studies.

The Key principles and major recommendations include:

Core Principles and Foundational Requirements

1. Mandatory Integration and ERAS Alignment: Nutritional care must be integrated into the overall management of the patient and support the principles of the Enhanced Recovery After Surgery concept.

2. High Metabolic Risk Definition: High metabolic risk before surgery is defined by the presence of at least one criterion: weight loss greater than 10–15% within six months, BMI under <18.5m/kg², NRS (nutritional risk assessment score) ≥5 or subjective global assessment (SGA) grade C, serum albumin <30g/L (exclusion of hepatic or renal insufficiency).

3. Assessment Tools: In surgical cancer patients, body composition should be assessed, using Computed Tomography (CT) software as the gold standard when available (Grade B). Furthermore, a frailty assessment should be routinely performed in older patients undergoing major surgery, as frailty predicts poor outcomes (Grade GPP).

Preoperative Nutritional Strategies

4. Fasting liberalization and metabolic conditioning: The guidelines strongly recommend abolishing prolonged fasting. Patients without aspiration risk should be allowed clear liquids up to two hours and solid foods up to six hours before anesthesia (Grade A). Additionally, carbohydrate loading should be selectively performed shortly before major elective abdominal surgery to counteract insulin resistance (Grade B/0).

5. Mandatory risk-based nutritional optimization: Patients identified with severe malnutrition and/or high metabolic risk should receive mandatory nutritional therapy (Grade A), preferably via the oral or enteral route (Grade A). A minimum period of 10–14 days of therapy should be considered, potentially postponing surgery (Grade B/GPP). Preoperative parenteral nutrition (PN) should only be used for this high-risk group if oral or enteral feeding is infeasible (Grade A).

6. Targeted supplementation (oral nutritional supplements (ONS) and Immunonutrition): Patients who fail to meet nutritional needs from regular food should be encouraged to take oral nutritional supplements (Grade GPP); ONS should be administered to match deficits in those with malnutrition or high metabolic risk (Grade A). Furthermore, patients undergoing major tumor surgery should be offered immunonutrition (fortified with arginine, omega-3 fatty acids, and nucleotides) preoperatively or perioperatively (Grade B).

Postoperative and Therapeutic Guidelines

7. Immediate enteral priority: Oral or tube feeding should be started as soon as possible in conscious and hemodynamically stable patients after surgery (Grade A). Enteral nutrition (EN) should be started within 24 hours if oral intake is expected to remain below 50% over the next seven days (Grade A/GPP).

8. Access and parenteral escalation: If less than 50% of energy needs cannot be met orally or enterally within three to four days, supplemental parenteral nutrition (SPN) should be added (Grade B). For high-risk patients undergoing major upper gastrointestinal procedures, intraoperative tube placement (nasojejunal or jejunostomy) should be considered to secure enteral access (Grade B).

9. Safety and refeeding prevention: To prevent refeeding syndrome, standard EN should be started at a low rate (10–30 mL/h) and cautiously increased, taking up to five days to reach the caloric target, only when electrolytes are stable (Grade GPP).

10. Nutrient profile: Postoperative parenteral nutrition should include omega-3 fatty acids (Grade B). Conversely, enteral glutamine should generally not be given (Grade A), and parenteral glutamine should not be administered to patients with severe hepatic, renal, or multiorgan failure (Grade A).

Follow-up and Long-Term Care

11. Post-Discharge Follow-up: Patients receiving perioperative nutritional therapy should have regular assessment during hospitalization and continuation post-discharge, including nutritional counseling and oral/tube supplementation as appropriate (Grade B).

12. Temporary Jejunostomy: An intraoperatively placed jejunostomy may be temporarily left in place at discharge to support weight maintenance or adherence to adjuvant chemotherapy (Grade GPP).

Special Consideration

13. Nutritional Considerations in Bariatric Surgery: Early oral diet resumption postoperatively is recommended, as it reduces nausea and shortens hospital stay without increasing complications. Lifelong, procedure-specific supplementation and regular monitoring are essential due to the high risk of nutrient deficiencies. In cases requiring relaparoscopy or laparotomy, nasojejunal or jejunostomy tube placement may be considered to ensure nutritional support (Grade GPP).

The updated ESPEN guideline, advances perioperative care by embedding nutritional support throughout the surgical pathway—from prehabilitation to post-discharge. It calls for routine screening for malnutrition, frailty, and sarcopenia, and mandates preoperative nutrition for high-risk patients, even if surgery is delayed. Outdated practices like prolonged fasting are replaced with liberalized intake, carbohydrate loading, and early oral or enteral feeding. With 44 evidence-graded recommendations, the guideline sets early, individualized, and sustained nutrition as a clinical standard, improving outcomes, specifically in high-risk patients.