Independent and combined influence of neonatal and current body composition on academic performance in youth: The <scp>UP</scp> &amp; <scp>DOWN S</scp>tudy

Summary Backgrounds Unhealthy body composition is a cause for concern across the lifespan. Objective The objective of this study was to examine the independent and combined associations between neonatal and current body composition with academic performance among youth. Methods This cross‐sectional study was conducted with a total of 1557 youth (745 girls) aged 10.4 ± 3.4 years. Birth weight and length at birth were self‐reported. Current body composition was assessed by body mass index ( BMI ), waist circumference ( WC ) and percentage of body fat ( BF %). Academic performance was assessed through schools records. Results Birth weight was related to all academic variables in boys, independent of potential confounders, including BMI ; whereas WC , BMI and BF % were related to all academic performance indicators in both boys and girls, independent of potential confounders, including birth weight (all P &lt; 0.05). In addition, the combined adverse effects of low birth weight and current overweight on academic performance were observed in both boys and girls for grade point average ( GPA ) indicator. Boys in the group with none adverse effect had significantly higher scores in GPA (score +0.535; 95% confidence interval, 0.082–0.989) than boys in the group of both adverse effects ( P &lt; 0.007); among girls, GPA score was higher in the group with none adverse effect than in the groups with one or two adverse effects ( P for trend = 0.029). Conclusions Neonatal and current body composition, both independently and combined, may influence academic performance in youth.