Press release

Mother's work can be beneficial to child body weight

Australian cohort study shows positive impact - up to a certain threshold

Up to a certain number of hours, maternal employment is beneficial for children’s body weight. This is the key finding by Jianghong Li (WZB Berlin Social Science Center) and her international collaborators who analyzed longitudinal data from the Western Australia Pregnancy Cohort Study (“Raine Study”). The finding contradicts previous research that linked longer working hours to children’s higher body mass index (BMI) suggesting that any maternal employment was a risk for child health.

The optimal number of hours in maternal employment depends on the developmental stage of the child: Among preschoolers, a risk of a child becoming overweight or obese is lower when a mother worked between 1 and 24 hours a week, compared to working 35 or more hours per week. 

Amongst school aged children (8-14 years) the risk decreased when a mother worked between 35 and 40 hours per week, compared to working shorter (1-24) or longer hours (41 or more) a week.

This effect also differs by family income: it is stronger in low to medium income families, compared with high income families.

Fathers’ work hours also matter. When fathers worked less than 45 or more hours per week, the  risk of child overweight or obesity associated with  long maternal work hours (41 or more) or short hours (1-24) decreased, compared to when fathers worked 45 or more hours among school aged children from low to medium income families.

The researchers concluded that mothers’ employment, up to a certain threshold, can bring to families positive gains.

“Employment supplies resources to a family such as income, but also psychological resources like social support, a valued identify, self-efficacy and optimism that we believe may make a difference,” Jianghong Li and her co-authors point out.

About the Raine Study

The Raine Study is a highly successful multi-generational longitudinal study which started in 1989. The study has enabled many important health discoveries and informed improvements to health policy and practice. The Raine Study is supported by the University of Western Australia, Curtin University, Edith Cowan University, Murdoch University, the University of Notre Dame, Telethon Kids Institute, Women and Infants Research Foundation and the Raine Medical Research Foundation (founded by Mary Raine in 1957). Further details on the Raine Study are available at

About the Research

Jianghong Li,Plamen Akaliyski, Jakob Schäfer, Garth Kendall, Wendy H.Oddy, Fiona Stanley, Lyndall Strazdins,Non-linear relationship between maternal work hours and child body weight: Evidence from the Western Australian Pregnancy Cohort (Raine) Study. Social Science & Medicine, 2017, volume 186, 52-60.

A post print of the article can be down loaded here.


Jianghong Li: [at]

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