INTRODUCTION:Promoting water consumption as an alternative to sugar-sweetened beverages helped to prevent overweight among students in a trial of the Water First intervention. This study investigated the heterogeneity of effects on weight and beverage consumption by child sociodemographic, family, and health-related characteristics.
METHODS:In 2016-2019, elementary schools were randomized as controls or to receive the Water First intervention, combining environmental and educational approaches to promote water consumption. In this secondary analysis conducted in 2024, outcomes were BMI z-score and frequency of water and sugar-sweetened beverages consumption at the 15-month follow-up. The moderating effects of baseline, sex, Hispanic ethnicity, number of caregivers, home connectedness, and acculturation were examined with mixed-effect models by testing an interaction with intervention status.
RESULTS:Overall, 1,250 4th-grade students were included. For each additional unit of baseline sugar-sweetened beverages consumption, the 15-month frequency of sugar-sweetened beverages consumption was 5% (proportional increase=0.95; 95% CI=0.91, 0.98) lower in the intervention than in the control group. The effect of Water First in increasing water consumption was estimated to be lower in students speaking English and Spanish at home (proportional increase=0.80; 95% CI=0.61, 1.04) than in those with a lower acculturation status, speaking only Spanish. There were no other important moderators.
CONCLUSIONS:Water First had largely consistent effects across sociodemographic, family, and health-related characteristics. However, effects were more pronounced for students with higher baseline sugar-sweetened beverages consumption and lower acculturation. Water First is therefore a valuable program for promoting healthier beverage consumption and preventing overweight in children from diverse backgrounds.