Effects of school-based interventions targeting obesity-related behaviors and body weight change: a systematic umbrella review.

This umbrella review analyzed the effectiveness of school-based interventions, applying body weight or behavioral outcomes. Twelve systematic reviews and five meta-analyses (examining 196 trials) were included. Results indicated that the effectiveness was usually referred to body weight or BMI change, with 1/3 of trials (per review) indicating significant changes in BMI or obesity prevalence. Meta-analyses yielded mixed effects (three showed significant changes in weight, BMI, or obesity). Interventions were more effective if they aimed at a reduction of sedentary behaviors, incorporated moderate-to-vigorous physical activity, and parental involvement. The inclusion of a nutrition component moderated the long-term effects of interventions. More efficient interventions lasted at least 3 months, did not aim solely at environmental changes, and were implemented in general population. Female and younger participants may benefit more from the interventions. The role of psychological theories and behavioral or cognitive mediators was rarely investigated.