Efficacy of a School-based Obesity Prevention Program in Mexican Schoolchildren: Cluster Randomized Controlled Trial

There is evidence that obesity prevention programs show positive effects on obesity and lifestyle parameters. However, the effect of the programs delivered by different implementers is unknown, and in Mexico, the available studies present methodological limitations. The aim of this study is to evaluate the feasibility and efficacy of a school-based obesity prevention program implemented by nutrition and physical activity advanced students compared to a control group and implemented by school teachers compared to a control group of Mexican schoolchildren. This is a cluster randomized controlled trial. Schoolchildren from different public schools in Hermosillo , Sonora will be invited to participate. The schools will be randomly assigned to one option:1) the Planet Nutrition Program (PPN) delivered by advanced students, 2) PPN by school teachers, or 3) a control group. A 6-month pilot study with a follow-up at 8 months (after the summer holidays), followed by a definitive study with a follow-up at 8 and 12 months will be conducted.The intervention will consist of nutrition education sessions, physical activity, and the provision of nutrition information for parents. The BMI Z-score, body fat, other obesity, and lifestyle parameters will be evaluated at baseline and at the end of the study. A mixed effects model will be used to evaluate the differences between the groups. The investigators expect that the program could be a model of obesity prevention with a high potential for dissemination in Mexican schools.