Long sleep duration and childhood overweight/obesity and body fat

To assess the association between short sleep duration and overweight/obesity and body fat (BF) and to identify correlates of short sleep duration in a sample of Portuguese children. A cross‐sectional study of children 7–9 years (n = 4511) was performed between October 2002 and June 2003. Weight, height, and skinfolds were measured, and parents filled out a questionnaire about family characteristics as well as sleep duration. The prevalence of overweight/obesity and BF (%) both decreased by long sleep duration. After adjusted for confounders, the odds ratio (OR) for overweight/obesity and sleep duration were as follows: reference >11 h/d; 10–11 h/d, OR: 1.3; confidence interval (CI):1.26, 1.33; 9–10 h/d, OR: 1.16; CI: 1.13, 1.19; and