Prospective associations between weekend catch-up sleep, physical activity, and childhood obesity

Background: Catch-up sleep and low physical activity on weekends have been commonly documented. Preliminary evidence on Chinese children, however, has shown a variety of weekly physical activity patterns. This study examined the prospective associations between weekend catch-up patterns of sleep and physical activity and obesity over a 2-year period in Chinese children. Methods: Prospective data from 599 children in the Understand Children's Activity and Nutrition (UCAN) cohort study were analyzed. Weekly patterns of obesogenic behaviors (physical activity and sleep duration) were assessed annually over a 2-year period. Moderate-to-vigorous physical activity (MVPA) and sedentary time were determined by ActiGraph accelerometry. Data on sleep durations and sociodemographic factors were obtained from parental-reported questionnaires. Weekend catch-up sleep and MVPA patterns were calculated and examined in relation to childhood obesity after controlling for sociodemographic variables and sedentary time. Results: Every additional hour of average weekly sleep duration was associated with a 16% decrease in the odds of obesity (OR: 0.841, 95%CI: 0.709 - 0.999). After adjustment of average sleep duration, weekend sleep catch-up categories showed no association with obesity risk. Over a 2-year period, half of the children demonstrated weekend catch-up MVPA. Weekend catch-up MVPA for less than 20 minutes (OR: 0.473, 95%CI: 0.258 - 0.867) or more than 20 minutes (OR: 0.505, 95%CI: 0.257 - 0.993) were both related to lower risk of obesity. Conclusions: Weekend catch-up sleep did not ameliorate the risk of childhood obesity, whereas weekend catch-up MVPA did reduce that risk. More research is needed to explore the factors contributing to these obesogenic behavior patterns.