Sleep duration and overweight among Australian children and adolescents.

AIM To examine the association between sleep and overweight and waist circumference (WC) in children and adolescents. METHODS Data were from a nationally representative sample of 6324 7-15-y-old males and females from the Australian Health and Fitness Survey. Associations between sleep duration and body mass index (BMI) and WC were examined by analysis of covariance, linear regression, and logistic regression. RESULTS In the total sample, there was a significant main effect across sleep-duration categories (or=10 h) for BMI. Linear regression showed significant age, sex, age-sleep, and age-sex-sleep interactions in the total sample. There was an inverse graded relationship between sleep and BMI and WC in boys. In boys, there was a 1.6-1.8 times greater odds of overweight for those who reported 8-9 h or 9-10 h of sleep compared to those reporting>or=10 h of sleep. For boys reportingor=10 h of sleep. In contrast, no significant associations between sleep and overweight were found in girls. CONCLUSION Sleep duration was inversely related with overweight in young males but not females.