Parental Working Hours and Children's Sedentary Time: A Cross-sectional Analysis of the J-SHINE

Background: Sedentary behaviors are prevalent among children and can have a detrimental effect on their health. Little is known about the influence of parental time on children's sedentary behavior. This study examined the association between parental working hours and children's sedentary time. Methods: Cross-sectional data were drawn from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE) in 2010 and 2011. Participants were 886 children aged 7-18 years and their parents. The primary outcome was selfreported sedentary time after school that comprised screen time and non-screen time. The main explanatory variable was parental working hours. We used multiple regression analysis adjusting for sociodemographic factors. Results: Children's mean sedentary time was 222 (standard deviation [SD], 123) min/day; 144 (SD, 108) min/day screen time and 78 (SD, 65) min/day non-screen time. Children whose mothers worked >20 hours/week had 28 (95% CI, 9 to 48) min/day longer sedentary time than children of homemakers (240 min/day vs 214 min/day). The longer maternal working hours, the longer sedentary time (P for trend <0.01). In contrast, children whose fathers worked >48 hours/week had 82 (95% CI, -156 to -7) min/day shorter sedentary time than children of non-working fathers (179 min/day vs 264 min/day). When limited to children whose fathers worked, there was no statistically significant association between children's sedentary time and paternal working hours. Conclusions: Children with mothers who work long hours or fathers not working tend to sit more. Supplementing the shortages in resources for childcare may be necessary among those families.