• children;
  • depression;
  • moderator;
  • obesity;
  • self-esteem;
  • sleep duration


This study examined the moderating effects of different body mass index groups on the relationship between sleep duration and psychological variables (i.e. self-esteem, depression, and perceived obesity stress) among overweight and obese children in Korea. A non-experimental, cross-sectional study design was used. Study participants included 424 children residing in one metropolitan city of Korea and participating in weight-control programs. Self-reported data collection and physical examinations were performed. An age- and sex-specific reference growth chart was used to produce body mass index for age percentiles, and to classify overweight and obese groups. The results indicated that the main effects of sleep duration and the body mass index group × sleep duration interaction terms were statistically significant for all investigated psychological variables (P < 0.05), indicating that the body mass index group variable moderated the relationship between sleep duration and these psychological variables. This study found that sleep duration < 7 h was particularly detrimental to the investigated psychological variables in overweight, rather than obese, children.