Researchers in Norway have discovered a possible link between divorce and childhood obesity, especially among boys. The researchers looked at health data from school nurses on more than 1,000 third grade kids (about 8 years old) at 127 different schools in the Scandinavian country. About a fifth of the kids were overweight or obese as defined by the International Obesity Task Force (IOTF). Almost a 10th were abdominally or centrally obese, which means they had a waist circumference that is at least half their height. (A large girth has been connected to several adverse health outcomes, including heart disease and diabetes.) That’s worrying enough. But the boys and girls whose parents were divorced were 50% more likely to obese and almost 90% more likely to be abdominally obese than those whose parents were married. They were even more likely to be obese than kids whose parents had never married. Even when other factors were taken into account, including how educated the mother was—usually the highest predictor of childhood obesity—the findings held true. And for boys, the likelihood of unhealthy weight was even higher. They were 63% more likely to be generally overweight than boys with married parents. And they were 104% more likely to have too much weight on their waist. “We wanted to understand how ongoing changes in society and in children’s daily lives can be related to the development of overweight and obesity,” says Dr. Anna Biehl, an epidemiologist at Norwegian Institute of Public Health and one of the authors of the paper. “Since 1975, the number of divorces has increased and a greater proportion of children today are living for much of their childhood with divorced parents. Knowledge about this is important for preventive work.” It’s not completely clear that the parental divorce was the cause of the obesity, although other studies have found similar effects. There is ongoing discussion among sociologists as to whether divorce leads to poverty or if it’s more true that poverty leads to divorce. Poverty, at least in developed countries, is linked with childhood obesity. So poverty could be the cause of both the divorce and the obesity. Or, as the study notes, there could be other variables: “Health, socioeconomic resources, psychological characteristics, values and preferences affect the chance of marrying and remaining married,” it says, “and has previously been found to account for some of the differences between children of divorced and married parents.” One way to adjust for that in future studies would be to compare the kids’ measurements before and after the marriage dissolved, but this study was not able to do that. Biehl is very reluctant to speculate on why kids of divorce have weight issues. But other research has indicated that women usually take a bigger financial hit when divorced, they usually get custody of minor children and they usually do the bulk of the cooking in most households. All of those things will be harder to do as a single parent which could have health repercussions. There may simply be less household income to spend on food, less time spent on cooking, less mental bandwidth to spend on watching over kids’ health and exercise regime. But there could also be an emotional component. It’s rare that a divorce doesn’t lead to disruption in a child’s life, either through conflict or merely the selling or moving out of a family home, all of which can cause stress. “Such emotional stress may impact on eating behavior and physical activity level,” says the study. Previous studies have hinted that parents might become less strict about healthy lifestyles—allowing children more screen time or to eat when they weren’t hungry, for example—as a way to curry favor with the kids or out of guilt. As to why it hits boys harder? Again, it’s largely speculation, but they tend to have fewer mechanisms for expressing their feelings and often lose a male role model and are therefore more vulnerable when families dissolve.