The Effectiveness of Oral Nutrition Supplementation on Growth Indicators, Dietary Intake, Appetite, and Health Outcomes Among Underweight Preschool Children in Urban Area of Kuala Lumpur, Malaysia: A Multi-Centre Community-Based Randomised Controlled

Background/Objectives: Undernutrition remains a public health concern among preschool children in Malaysia. Although oral nutritional supplementation (ONS) globally has been recommended to improve nutritional status, evidence from community-based randomised controlled trials among underweight Malaysian preschool children remains limited. This study evaluated the effectiveness of ONS on growth, dietary intake, appetite, and common illnesses among underweight preschool children in Kuala Lumpur, the capital city of Malaysia. Methods: A multi-centre, community-based, cluster-randomised controlled trial was conducted among underweight preschool children aged 4–6 years from 16 government-subsidised preschools. Participants were assigned to receive ONS plus nutrition education (ONS + NE) or nutrition education alone (NE only) for 90 days. Anthropometric measurements, dietary intake, appetite, attainment of catch-up growth, and parent-reported common illnesses were assessed. Between-group differences were analysed using analysis of covariance adjusted for baseline values. Results: Ninety-six underweight preschool children were randomised to ONS plus nutrition education (ONS + NE, n = 56) or nutrition education alone (NE only, n = 40). Compared with the NE group, children receiving ONS + NE demonstrated significantly greater improvements in weight-for-age z-scores at day 60 and day 90 (p < 0.05). The ONS + NE group also achieved significantly higher catch-up growth attainment at day 60 (116.6 ± 38.5% vs. 99.1 ± 17.4%; p = 0.029) and day 90 (114.6 ± 37.2% vs. 95.5 ± 23.8%; p = 0.021). In addition, significantly higher energy, macronutrients, selected micronutrient intakes, and appetite scores were observed in the ONS + NE group (all p < 0.05). Conclusions: ONS combined with nutrition education improved weight-related growth, dietary adequacy, catch-up growth energy achievement, and appetite among underweight preschool children. ONS may serve as an effective community-based strategy for nutritional rehabilitation in this population. Trial registration: ISRCTN15093638.