Perioperative nutrition and multidisciplinary care in gastrointestinal oncology surgery: Evidence-based strategies to enhance recovery and inform readmission prevention

Table 3 Narrative grading of the strength of evidence supporting major perioperative nutritional interventions in gastrointestinal oncology surgery

Recommendation	Evidence grade	Principal supporting evidence
Routine nutritional screening	High-quality evidence	ESPEN and ERAS guidelines; multiple observational studies and validated screening studies
Oral nutritional supplements in patients unable to meet requirements orally	High-quality evidence	ESPEN recommendations; randomized and comparative studies
Early oral feeding after gastrointestinal surgery	High-quality evidence	Randomized controlled trials; systematic reviews and meta-analyses
Enteral nutrition when oral intake is inadequate and the gastrointestinal tract is functional	High-quality evidence	Randomized trials; systematic reviews/meta-analyses; international guidelines
Preoperative parenteral nutrition in selected severely malnourished patients	Moderate-quality evidence	ESPEN recommendations; randomized and comparative studies
Immunonutrition in selected high-risk/major gastrointestinal surgery	Moderate-quality evidence	Randomized controlled trials; systematic reviews/meta-analyses; guideline recommendations
Multimodal prehabilitation	Moderate-quality evidence	Randomized controlled trials; systematic reviews and meta-analyses
Goal-directed fluid therapy	Moderate-to-high-quality evidence	Randomized trials; systematic reviews/meta-analyses; ERAS recommendations
Multidisciplinary ERAS care	High-quality evidence	ERAS implementation studies; prospective cohorts; systematic reviews
Procedure-specific nutritional pathways	Moderate-quality evidence	Procedure-specific guidelines, cohort studies, and comparative studies
Post-discharge dietitian-led nutritional follow-up	Moderate-quality evidence	Cohort and intervention studies; clinical guidelines
Structured transitional care for prevention of readmission	Moderate-quality evidence	Transitional-care studies; observational and comparative evidence
Telemedicine and digital nutritional monitoring	Emerging evidence	Pilot studies; observational studies; early comparative studies
AI-assisted nutritional/body-composition assessment	Emerging evidence	Early validation and retrospective/observational studies
Precision nutrition based on body composition, metabolic, inflammatory, or microbiome characteristics	Emerging evidence	Translational, observational, and early clinical research

Evidence was graded narratively according to the hierarchy, quality, consistency, and clinical applicability of the available literature. High-quality evidence denotes recommendations supported by multiple randomized controlled trials, systematic reviews/meta-analyses, and/or consistent international guideline endorsement. Moderate-quality evidence denotes recommendations supported by randomized or prospective evidence that is limited in quantity, heterogeneous, procedure-specific, or supplemented primarily by observational studies. Emerging evidence denotes interventions supported mainly by preliminary clinical, observational, technological, or translational research for which clinical effectiveness remains incompletely established. Where recommendations are based predominantly on consensus or limited clinical data, they should be interpreted as expert opinion rather than formal evidence grades. This framework is descriptive and pragmatic and does not represent a formal GRADE assessment. Importantly, evidence demonstrating improvement in intermediate outcomes such as nutritional adequacy, complications, or length of stay was not assumed to constitute direct evidence of reduced 30-day readmission. ERAS: Enhanced recovery after surgery; ESPEN: European Society for Clinical Nutrition and Metabolism; AI: Artificial intelligence.