Childcare Environment and Japanese Children Who Are Overweight in Early Childhood.

Background: Maternal employment may affect child care styles and contribute to the increasing prevalence of overweight children. We explored the potential risk factors for becoming overweight during early childhood, especially in the child care environment.

Methods: We conducted a retrospective cohort study using data from health check-up services from 2007 to 2015 in Kobe, Japan. The main outcome was being overweight at age 3 years, which was defined by the International Obesity Task Force cutoffs. Environmental, maternal, and infantile factors were examined as possible risk factors for childhood overweight.

Results: Of 31,463 infants, 1315 (4.2%) were classified as overweight at age 3 years. Compared with children who were cared for by their mothers during the day at 4 and 18 months, the adjusted odds ratio (aOR) for becoming overweight for those who were not cared for by their mothers was 1.52: 95% confidence interval (CI), 1.16-1.99. Long sleep duration was associated with lower risk of childhood overweight: aOR, 0.79; 95% CI, 0.66-0.96.

Conclusion: Less daytime care by mothers and shorter sleep duration were associated with increased risk of becoming overweight during childhood. Further studies are needed to determine on how the effect of those factors may be diminished with respect to childhood overweight.