Effectiveness of peer-led programs for overweight and obesity in children: systematic review and meta-analysis.

Child health promotion has used peer-led interventions for decades, but their effectiveness for childhood obesity is unknown. This review assesses the effectiveness of peer-led interventions on child and adolescent obesity using a range of adiposity outcomes. We included studies that used a peer-led approach for delivering behavior change communications with a minimum intervention duration of four weeks. Studies needed to report results for any of the outcomes: BMI, BMI z-score or BMI percentile. The review included 14 studies of moderate to high quality from high-income countries. A meta-analysis involving 2506 children from 9 studies showed that programs were effective with a mean difference in BMI of -0.15 kg/m2 (95% confidence interval [-0.26, -0.03]), p = 0.01. Heterogeneity was low (I2 = 28%, p = 0.19) for children in the intervention group. The mean difference varied with subgroups with significantly greater effects from interventions that focused on physical activity alone or with longer duration of implementation. Sensitivity analysis showed similar significant findings to the primary meta-analysis. We found moderately strong evidence to support the advantageous effect of peer-led interventions for obesity prevention in children and adolescents. However, given the small number of studies included, and possible reporting bias, the results must be interpreted cautiously.