Effects of oral nutritional supplement on growth and body composition in malnutrition at risk and malnourished children: MARVEL study, a multi-center randomized controlled trial

Purpose This study investigated the effect of oral nutritional supplement (ONS) on growth and body composition in undernourished children. Methods Thai children aged 1–6 years with weight-for-height (WFH) z-scores between − 1 SD and − 3 SD were randomized (1:1) to receive either dietary counselling alone (DC group) or counselling plus 420 mL/day of a cow’s milk–based ONS (1 kcal/mL; energy distribution: 10% protein, 49% carbohydrate, 41% fat; fortified with calcium, vitamin D, iron, and zinc) for 3 months. Weight and height were measured at baseline, 1, and 3 months and compared with WHO standards. Body composition was assessed via bioelectrical impedance analysis in children aged ≥ 3 years old at the same period. Results A total of 159 children (78 DC and 81 ONS), with mean ages (95% CI) of 3.5 (3.15–3.90) and 3.49 (3.10–3.90) years, were included. After 3 months, the ONS group demonstrated higher gains in weight, height, weight-for-age (WFA) and weight-for-height (WFH) z-score compared to the DC group [mean difference (95% CI): weight 0.16 (0.04–0.28) kg; height: 0.42 (0.05–0.79) cm; WFA z-score: 0.10 (0.01–0.18); WFH z-score: 0.13 (− 0.02 to 0.27)]. Gains in fat-free mass were higher with ONS at both 1 and 3 months [mean difference (95%CI): 0.26 (0.01–0.50) and 0.36 (0.10–0.63) kg]. Soft lean mass gain was also significantly greater in the ONS group at 3 months [0.39 (0.11–0.68) kg]. Conclusions ONS combined with dietary counselling improved growth and fat-free mass, supporting its role in promoting healthier body composition and long-term metabolic health. TCTR20220908004. Category of study Randomized controlled trials.