Effect of Nutrition Interventions on BMI in Youth Attending After-School Programs: A Meta-Analysis


      To evaluate the effectiveness of nutrition interventions in reducing Body Mass Index (BMI) for youth participating in after-school programs conducted solely at school.

      Design, Setting, Participants

      Overweight and obesity in youth are problematic. After-school nutrition interventions could be beneficial for addressing youth weight issues; however, the effectiveness of these programs on reducing BMI is unclear thus a meta-analysis was performed.

      Outcome Measures and Analysis

      Nine databases (e.g. CINAHL, EBSCO, PubMed, etc.) were searched with terms such as ‘‘Diet,’’ ‘‘Nutrition,’’ ‘‘Body Mass Index,’’ and ‘‘After-School.’’ The mean and standard deviation of BMI change scores were extracted to calculate effect size (ESs). A random effect model was used to calculate an overall ES and 95% confidence interval (CI). Moderator analyses were conducted for parent involvement (yes/no) and type of intervention (nutrition only, nutrition + physical activity, nutrition + physical activity + other) on overall ES. Heterogeneity was evaluated using Cochran's Q statistics. Comprehensive Meta-Analysis (2.2) software was used to conduct ES calculation and moderator analyses.


      The searches yielded 1702 articles. After initial screening, 111 potentially relevant studies were fully reviewed. Seventeen studies involving 1,716 participants were included and 18 ESs were calculated. Overall mean ES was significant (ES = -0.156, CI = -0.29, -0.02) which indicated that school-based, after-school nutrition intervention programs were effective in reducing BMI. Moderator analyses indicated that the mean ES was influenced by type of intervention and parental involvement, Qbetween = 16.26, df = 2, p < .001 and Qbetween = 4.56, df = 1, p = .033, respectively.

      Conclusion and Implications

      This meta-analysis indicated that nutrition interventions in after-school, school-based settings are effective in reducing BMI among youth.



      Supplementary data