Mediators of the association between childhood body mass index and educational attainment: Analysis of a UK prospective cohort study

BackgroundHigher body mass index (BMI) in childhood is associated with lower academic achievement. ObjectiveTo explore potential pathways linking childhood BMI with educational attainment. MethodsUsing data from the Avon Longitudinal Study of Parents and Children prospective cohort study (N = 6949), we assessed the association between BMI z-scores at 11.7 years and educational attainment at 16 (General Certificate of Secondary Education [GCSE] results). Depressive symptoms, externalizing behaviours, bullying and school enjoyment were considered as potential mediators. Mediators were examined individually and jointly using sequential causal mediation. ResultsHigher BMI z-scores were associated with lower GCSE scores (females beta = -3.47 95% CI -5.54, -1.41 males beta = -4.33 95% CI -6.73, -1.94). Together, bullying, externalizing symptoms, depressive symptoms and school enjoyment mediated 41.9% of this association in females, and 23.3% in males. In males, evidence for mediation was weak (confidence intervals for all indirect effects spanned the null). In both females and males, most of the mediation was driven by externalizing symptoms. ConclusionsThe detrimental effect of higher BMI on educational attainment appears to be partly explained by externalizing behaviours, particularly in females. Interventions to support behavioural problems may help the academic achievement of children with a higher body weight.

Automated summary

This study examines the association between BMI and educational attainment and finds that in females, externalizing behaviors are a major mediator of the negative impact of BMI on educational achievement, while in males there is no significant mediation effect. Therefore, supporting behavioral problems may help improve the academic performance of overweight children.