Weekend catch-up sleep is associated with decreased risk of being overweight among fifth-grade students with short sleep duration.

Previous studies have reported a relationship between short sleep duration and childhood overweight. Although school-aged children tend to compensate for weekday sleep deficit by increasing weekend sleep duration, the association between weekend catch-up sleep and childhood overweight remains unclear. This study aimed to examine the relationship between weekend catch-up sleep and being overweight in children. A total of 936 school children (48.2% boys) aged 10 or 11 years participated in this school-based cohort study. Anthropometric measurements including height and body weight were carried out. We obtained data on sleep patterns, lifestyle and parent characteristics using questionnaires. The main outcome measure was childhood overweight. After adjusting for the relevant confounding variables (age, sex, breakfast eating, screen time and parental obesity), longer sleep on weekdays and weekends was associated with decreased odds of childhood overweight (OR: 0.68; 95% CI: 0.54-0.86; OR: 0.64; 95% CI: 0.53-0.77, respectively). Participants with increased catch-up sleep duration during weekends also had decreased odds of being overweight (OR: 0.67; 95% CI: 0.53-0.85). There was an interaction between weekday sleep duration and weekend catch-up sleep in relation to childhood overweight, and this effect of weekend catch-up sleep on being overweight was stronger as the participants slept less on weekdays (P = 0.024). These results indicate that weekend catch-up sleep is independently associated with decreased risk of being overweight in fifth-grade students, and this effect can be varied by the weekday sleep duration. A prospective study is required to confirm this observation.