What's behind the epidemic increase in childhood obesity? Does a mother's employment status play a role?
It used to be that parents could expect their children to outgrow their baby fat by the time they reached adolescence. But these days, public health officials say childhood pudginess is more often leading to lifelong problems with overweight and obesity. In fact, the U.S. Department of Health and Human Services recently reported that the percentage of overweight children has tripled since 1980, rising to about fifteen percent - or ninety million kids - between the ages of six and nineteen.
Economists and public health officials alike have reason to worry about these numbers. Both the financial and health costs of childhood obesity, which some experts describe as epidemic, are astounding. A report last year from the Centers for Disease Control and Prevention said hospital costs related to childhood obesity had reached a "disturbing" $127 million in 1999 - a three-fold increase from 1979. Health conditions long thought to be limited to adults, such as Type 2 (adult-onset) diabetes, gall bladder disease, and sleep apnea, are occurring in greater numbers among overweight children. The problem is so severe that some pediatricians are even recommending surgery and drug therapy, measures previously reserved for adults.
While everything from fast food to video games has been blamed for this disturbing trend among American children, some social commentators are looking deeper to see if changes in the modern social fabric have created the problem. In particular, they hint that the movement of more and more women into the workforce in recent decades might have had a direct link to the epidemic rise of obesity in children.
Dartmouth economist Patricia Anderson, along with colleagues at the Federal Reserve Bank of Chicago and Wellesley College, is investigating the possible causal link. "While earlier studies have pointed out correlations between obesity and other factors, none of them has attempted to show causation," she says.
"We used econometric techniques to control for a variety of observable and unobservable factors, like socio-economic status, education, and mother's weight. That allowed us to focus specifically on the effect a mother's employment has on her children," Anderson says.
The recently completed study will set many mothers' minds to rest: in most families, the researchers found having a working mother does not increase the odds that children will be overweight. The one notable exception came where Anderson and her partners least expected to find it: among the country's most affluent families.
"In the initial part of the project, we looked at the data overall without distinguishing between smaller subgroups, and we saw a definite causal link between mother's work and a child's weight," Anderson says. "Then we went the next step and broke down the results by economic, social, and racial groups. To our surprise, while children in the poorest families were the most likely to be overweight, their weight problems weren't made worse by their mothers' jobs - but children in the wealthiest families did experience a significant effect," says Anderson. In fact, as much as twelve to thirty-five percent of the increase of overweight in the wealthiest group can be tied to a mother's work, according to the study.
Anderson believes the study's results, although in some ways counterintuitive, make sense in the larger picture of a family's day-to-day life.
"Higher obesity rates in poor or less-educated families could be a result of many things that ultimately have a greater impact on a child's health than a mother's employment. For example, there might be a lack of knowledge about proper nutrition, or the family might have less access to fresh fruits and vegetables, or maybe there are fewer opportunities to participate in physical activities," she says.
The study, which used data from the National Longitudinal Survey of Youth, also reinforced what working mothers have known for decades: By introducing additional time constraints on a mother's schedule, a job diminishes the amount of time available for planning and preparing meals or for overseeing a child's dietary habits.
People in lower economic groups probably already face significant time and resource constraints, regardless of whether a mother works. "So, if a mother in a less affluent family moves into the workforce, there is probably just a marginal effect on her children compared to wealthier families," she says.
In families where a mother's employment did have an impact on children's weight, the effect was exacerbated as the number of hours she worked per week increased over time. However, the study also found that children whose mothers worked while they were infants or toddlers were not necessarily at greater risk for being overweight than children whose mothers waited until the children were older to enter the workplace.
Although some people might question why fathers' work wasn't also included in the study, Anderson says there are very pragmatic reasons for focusing on mothers.
"Right or wrong, women still tend to bear more responsibility for child rearing than do men," she says. "Also, we've got better data to work with for women. Men's employment has remained about the same over the years at the same time women's has changed substantially."
While some commentators advocate returning to traditional household structures to combat social ills like childhood obesity, Anderson takes a more pragmatic view.
"This is the direction that society is moving in, and we need to focus on how to provide better nutrition and exercise for kids within these time and resource constraints," she says. "A mother who works outside the home is an economic necessity for many families. Perhaps we should be thinking about how to distribute the household load more evenly between men and women, because these constraints are having harmful side effects on family health."