Effectiveness of preventive school-based obesity interventions in low- and middle-income countries: a systematic review

BACKGROUND: The prevalence of childhood obesity is increasing rapidly in low- and middle-income countries, and informed policies to tackle the problem must be defined. OBJECTIVE: We systematically reviewed the evidence on the effectiveness of school-based interventions targeting dietary behavior and/or physical activity for the primary prevention of obesity in children and adolescents aged 6-18 y in low- and middle-income countries. DESIGN: We searched the MEDLINE, EMBASE, Web of Science, CENTRAL, ERIC, Cochrane Library, and Centre for Reviews and Dissemination databases for peer-reviewed controlled studies published in English, Spanish, French, German, or Dutch between January 1990 and July 2011. The quality of the included studies was appraised independently by 2 authors who used the Effective Public Health Practice Project tool. RESULTS: From a total of 7218 unique references, we retained 22 studies. Most of the interventions (82%) had a positive effect on dietary behavior and physical activity behavior (effect size ranged from -0.48 to 1.61). BMI decreased in 8 studies (effect size ranged from -0.7 to 0.0). Effective interventions targeted both diet and physical activity, involved multiple stakeholders, and integrated educational activities into the school curriculum. CONCLUSIONS: School-based interventions have the potential to improve dietary and physical activity behavior and to prevent unhealthy body weights in low- and middle-income countries. To reach their full potential, interventions should conduct process evaluations to document program implementation. The effect and the pathways through which interventions have this effect need to be better documented through rigorous evaluation studies.