Non-linear relationship between maternal work hours and child body weight: Evidence from the Western Australian

Jianghong Li1, Plamen Akaliyski2, Jakob Schäfer2

  • 1WZB Berlin Social Science Center, Reichpietschufer 50, 10785 Berlin, Germany; Telethon KIDS Institute, The University of Western Australia, PO Box 855, West Perth, Western Australia 6872, Australia; Center for Population Health Research, Curtin University, GPO Box U1987, Perth, Western Australia, Australia.

Using longitudinal data from the Western Australia Pregnancy Cohort (Raine) Study and both random-effects and fixed-effects models, this study examined the connection between maternal work hours and child overweight or obesity. Following children in two-parent families from early childhood to early adolescence, multivariate analyses revealed a non-linear and developmentally dynamic relationship. Among preschool children (ages 2 to 5), we found lower likelihood of child overweight and obesity when mothers worked 24 h or less per week, compared to when mothers worked 35 or more hours. This effect was stronger in low-to-medium income families. For older children (ages 8 to 14), compared to working 35-40 h a week, working shorter hours (1-24, 25-34) or longer hours (41 or more) was both associated with increases in child overweight and obesity. These non-linear effects were more pronounced in low-to-medium income families, particularly when fathers also worked long hours.

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