The effect of participation in school-based nutrition education interventions on body mass index: a meta-analysis of randomized controlled community trials.

Objective: The aim of this study was to evaluate the effectiveness of school-based nutrition education interventions in reducing or preventing overweight and obesity among children and adolescents.

Methods: We conducted a systematic search of 14 databases until May 2010 and cross-reference check in 8 systematic reviews (SRs) for studies published that described randomized controlled trials conducted in schools to reduce or prevent overweight in children and adolescents. An additional search was carried out using PubMed for papers published through May 2012, and no further papers were identified. Body mass index (BMI) was the primary outcome. The title and abstract review and the quality assessment were performed independently by two researchers. The software EPPI-Reviewer3 was used to store, manage and analyze all data. This SR is registered at ClinicalTrials.gov (NCT00985972).

Results: From the 4888 references initially retrieved, only 8 met the eligibility criteria for a random-effects meta-analysis. The total population consisted of 8722 children and adolescents. Across the studies, there was an average treatment effect of -0.33 kg/m(2) (-0.55, -0.11 95% CI) on BMI, with 84% of this effect explained by the highest quality studies.

Conclusion: This systematic review provides evidence that school-based nutrition education interventions are effective in reducing the BMI of children and adolescents.