Penny Gordon-Larsen, an assistant professor of nutrition at the University of North Carolina at Chapel Hill, and her colleagues analyzed data collected from more than 13,000 American teens enrolled in a longitudinal study. The researchers found that while obesity was lower among white teens from higher income and better educated households, the association did not bear out for black teen girls whose households were educated and had high incomes.
For years, the perception has been that as income and education rise, the levels of obesity decline as teens learn to make better nutritional choices and have the income to pay for such things as access to health clubs, Gordon-Larsen says.
However, more recently, researchers are finding that's not the case across all ethnic and racial groups.
In the new analysis, published in the latest issue of Obesity Research, the researchers found more evidence that boosting income and education doesn't work for all groups of people, Gordon-Larsen says. "For black females, overweight remained elevated across all income and education levels." The rates of obesity did decline as income and education rose for white, Hispanic and Asian girls, the researchers found.
When they looked at the boys in the study, the researchers found a less dramatic relationship between income and education and obesity. "The differences we see are not as striking," Gordon-Larsen says. Still, they found higher rates of obesity among black and Hispanic teen boys compared to white and Asian boys.
"You can't get rid of overweight by increasing people's income and education," Gordon-Larsen says. "We need to look beyond income and education."
So-called environmental factors -- such as access to parks for exercise -- must be taken into consideration to stem the obesity epidemic among young people, she adds. Cultural awareness of the importance of exercise must be raised in some groups, she says.
"We need to look at modifiable factors that we can do something about -- and to pay particular attention to disadvantaged neighborhoods," Gordon-Larsen says. Another idea is to boost opportunities for healthy eating, she adds.
Another expert, Marilyn Winkleby, an associate professor of medicine at Stanford University School of Medicine who has also researched the topic, is not surprised by the study's conclusions.
"She's (Gordon-Larsen) saying that even when you get to higher levels of socioeconomic status and education among blacks and Hispanics, overweight is still a problem," Winkleby says.
Winkleby believes the onus should not be only on the individual to change environmental factors. Rather, society has an obligation to change to make it easier for people to maintain a normal weight.
For instance, she says, schools might change policies as far as the availability of soft drinks on campus. She notes that large-sized soft drinks, in particular, have hundreds of empty calories and too much sugar.
"You can make available safe places for people to exercise," she adds. "Open the [school] gyms at night -- the kids will go."