While being overweight or obese in adolescence may have detrimental effects on academic attainment, the evidence base is limited by reliance on cross-sectional studies with small sample sizes, failure to take account of confounders, and lack of consideration of potential mediators. The present study aimed to address these limitations and examine longitudinal associations between obesity in adolescence and academic attainment.
Associations between weight status at 11 years old and academic attainment assessed by national tests at 11, 13 and 16 years were examined in the Avon Longitudinal Study of Parents and Children. Healthy weight was defined as BMI Z score <1.04; overweight as BMI Z score<1.04–1.63; obesity as BMI Z score =1.64.
Data from 5966 participants with objectively measured weight status were examined: 71.4% were healthy weight (1935 male; 2325 female), 13.3% overweight (372 male; 420 female) and 15.3% obese (448 male; 466 female).
Girls obese at 11 years had lower academic attainment at 11, 13 and 16 years compared to those of a healthy weight, even after controlling for a wide range of confounders. Associations between obesity and academic attainment were less clear in boys. The potential mediating effects of depressive symptoms, IQ and age of menarche in girls were explored but when confounders were included, there was no strong evidence for mediation.
For girls, obesity in adolescence has a detrimental impact on academic attainment five years later. Mental health, IQ and age of menarche did not mediate this relationship, suggesting that further work is required to understand the underlying mechanisms. Parents, education and public health policy makers should consider the wide reaching detrimental impact of obesity on educational outcomes in this age group.
- Academic attainment