Oral nutritional supplements versus a regular diet alone for body weight loss after gastrectomy: a phase 3, multicenter, open-label randomized controlled trial

Background Body weight loss (BWL) after gastrectomy is associated with not only a deteriorated quality of life but also a poor prognosis. Oral nutritional supplements (ONS) may be used to minimize BWL, which is observed in the first 3 months after gastrectomy and becomes stable thereafter, although the results of several randomized trials remain controversial. Methods We performed a multicenter, open-label randomized controlled trial including 1003 gastric cancer patients undergoing curative gastrectomy. Patients were assigned to the ONS group or the control group. In the former, 400 ml (400 kcal) per day for 12 weeks as enteral nutrition was planned, and the actual intake amount was recorded daily by patients themselves. The primary endpoint was BWL 1 year after gastrectomy. Results BWL data were available in 880 patients (ONS 437, control 443). BWL at 3 months was significantly lower in the ONS group than in the control group (7.1 ± 5.6% and 8.5 ± 5.8%, p = 0.0011). However, the difference gradually declined after 6 months and was not significant 1 year after surgery (9.3 ± 8.2% and 9.8 ± 8.7%, p = 0.37). In the ONS group, 50.4% of patients took more than 200 ml/day of ONS (average 301 ml) and showed significantly less BWL (8.2 ± 7.2%) at 1 year than the control ( p = 0.0204). Conclusion The administration of ONS for 12 weeks after gastrectomy did not improve BWL at 1 year. However, the improvement in BWL remained until 1 year after surgery in patients who took more than 200 kcal/day of ONS.