Sleep, but not other daily routines, mediates the association between maternal employment and BMI for preschool children

Background: It has been established that the more time mothers spend working outside of the home, the more likely their preschool-aged children are to be overweight. However, the mechanisms explaining this relationship are not well understood. Our objective was to explore child sleep, dietary habits, TV time, and family mealtime routines as mediators of the relationship between maternal employment status (full-time, part-time, and no or minimal employment) and child body mass index (BMI) percentile. Methods: Data were drawn from waves 1 and 2 of STRONG Kids, a prospective panel study examining childhood obesity among parent-preschooler dyads (n = 247). Mothers reported their own work hours, their child's hours of nighttime sleep, dietary habits, TV time, and mealtime routines. Trained staff measured child height and weight. Results: Compared to working 0-19 h/week, both full-time (>35 h/week) and part-time (20-34 h/week) employment predicted higher child BMI percentile 1 year later. Hours of child nighttime sleep partially mediated the association between maternal full-time employment and child BMI percentile. Adjusting for individual and family characteristics, children whose mothers were employed full time were less likely to sleep longer hours than children whose mothers were employed 0-19 h/week (b = -0.49, p < 0.04). Shorter child nighttime sleep was associated with higher BMI percentile (b = -7.31, p < 0.001). None of the other mediation pathways tested were significant. Conclusions: These findings add to the growing literature on the importance of adequate sleep for young children's health.