Wenqing Xu, Chuyuan Niu
Nutritional intervention after gastrectomy is central to postoperative recovery, but the optimal outpatient supplementation strategy remains uncertain. This systematic review assessed the efficacy and safety of oral nutritional supplementation (ONS) after hospital discharge in patients undergoing gastrectomy for gastric cancer. Eligible randomized controlled trials (RCTs) were identified from five databases through September 2025. Extracted outcomes included adverse events, laboratory indices, body composition, handgrip strength, and body-weight change. Seven RCTs involving 1,736 participants met the review criteria, although the number of trials contributing to each pooled outcome varied. ONS significantly attenuated absolute body-weight loss (WMD: 0.75 kg; 95% CI: 0.11 to 1.40) and percentage body-weight loss (WMD: 1.42; 95% CI: 0.78 to 2.07) compared with control care. Risk-of-bias assessment identified generally adequate randomization and allocation reporting in most trials, but certainty remains limited by the small number of trials, substantial heterogeneity in the primary weight outcome, and the absence of a formal GRADE assessment. No significant inter-group differences were found for body composition, handgrip strength, or laboratory markers. Adverse-event incidence was not significantly different between groups when analyzed with the fixed-effect model selected for minimal heterogeneity (RR: 1.17; 95% CI: 0.92 to 1.49). These findings suggest that post-discharge ONS may help reduce early to intermediate postoperative weight loss after gastrectomy without a clear safety penalty. Because most endpoints were assessed between 8 weeks and 3 months, the durability of benefit beyond this period remains unclear.