Children's BMI found to rise the longer their mothers work

February 4, 2011

Childhood obesity in the United States has more than tripled in the past three decades, and prior research has linked maternal employment to children's body mass index (BMI), a measure of their weight-for-height. A new study in the January/February issue of the journal Child Development has found that children's BMI rose the more years their mothers worked over their children's lifetimes.

Researchers at American University, Cornell University, and the University of Chicago used longitudinal information from the Study of Early Child Care and Youth Development, which was sponsored by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). They looked at 900 children in grades 3, 5, and 6 who lived in 10 cities across the country.

The researchers found that the total number of years mothers were employed had a small but cumulative influence on their children's BMI, which, over time, can lead to an increase in the likelihood of overweight or obesity. The findings were strongest among children in 5th and 6th grades. Surprisingly, changes in children's physical activity, time spent unsupervised, and time spent watching TV didn't explain the link between maternal employment and children's BMI. Moreover, the time of day moms worked wasn't significantly associated with children's BMI.

The reasons for these findings are not entirely clear. According to the authors, one possibility is that working parents have limited time for grocery shopping and food preparation. This may contribute to a greater reliance on eating out or eating prepared foods, which tend to be high in fat and calories.

Given that more than 70 percent of U.S. mothers with young children work, the importance of providing support to these families is clear. Based on their findings, the researchers call for efforts to expand the availability of affordable, readily accessible healthy foods, and to support and educate working parents about strategies for providing nutritious meals despite busy schedules.

"About a fifth of American children are considered obese, and childhood obesity has been associated with health, behavior, and academic problems in adolescence and adulthood," according to Taryn W. Morrissey, assistant professor in public administration and policy at American University, who led the study.

"Community- and school-based programs offer promise for promoting healthy weight by providing information to children and their families about nutrition and exercise, as well as how to make quick, healthy meals."

Provided by Society for Research in Child Development