A longitudinal study of sleep, weight status, and weight-related behaviors: Childhood Obesity Study in China Mega-cities.

Background: The aim of the study was to examine correlates of sleep and assess its associations with weight status and related behaviors.

Methods: Data were collected in 2015-2017 for 3298 children aged 6-17 years and their parents in 5 Chinese mega-cities. One thousand six hundred and ninety-one children with measured weight, height, and waist circumference in ≥2 surveys were included for longitudinal data analyses. Sleep and behaviors were self-reported.

Results: Cross-sectional data analyses found that older (β = -0.29, 95% CI: -0.32, -0.27) and secondary school children (β = -1.22, 95% CI: -1.31, -1.13) reported shorter sleep than their counterparts. Children with ≥college-educated (vs

Conclusions: Sleep among urban Chinese children varies by demographic factors. Longer sleep is associated with healthier weight-related behaviors and lower central obesity risk. Impact: Longer sleep was observed in younger, primary school children and children with college-educated parents. Longer sleep increased healthier weight-related behaviors and reduced general and central obesity risk. Provides data on the correlates of sleep duration of children. Gives insights on longitudinal relationships of sleep duration with weight-related behaviors and obesity risk. Findings help inform sleep interventions to increase sleep duration to prevent childhood obesity and unhealthy weight-related behaviors in urban settings of developing countries.