Children’s body mass index rises the longer mom works

Children’s chances of becoming overweight rise the longer their mothers work outside the home, researchers said Friday.

Weight problems among children have soared in the past three decades, as more women have joined the workforce. A consortium of researchers led by Taryn W. Morrissey of American University examined the relationship between kids’ weight and mothers’ work schedules and what factors about a woman’s work might contribute to child weight gain.

They used data from 990 school-aged children in the Study of Early child Care and Youth Development. The researchers had speculated that women who work non-traditional hours, such as evening shifts and weekends, might have children with a higher risk of weight gain. However, the mothers’ work schedules did not seem to make a difference.

But a mother’s working outside the home did matter. The longer the woman worked, the higher the likelihood that her child would become overweight. For example, for a child of average height, the increase in body mass index is equivalent to a gain in weight of nearly one pound for every five months the mother was working beyond what would typically be gained as a child ages.

Children in fifth and sixth grade were the most likely to gain weight when their mothers worked compared with younger and older children. “It’s possible that because 5th and 6th graders generally have more independence and less adult supervision over their time use and food choices than third graders, maternal employment precipitates poorer food choices and more sedentary activity,” they wrote.

What causes the increased risk from mothers’ working? It doesn’t appear related to the time a mother spends with a child, changes in a child’s physical activity, time spent unsupervised or time spent watching TV. Instead, the authors suggest, it may be that working mothers have less time to shop for healthy foods and cook at home and may resort more often to take-out food that is higher in calories.

The study appears in the journal Child Development.

Return to Booster Shots blog.