The conclusion of the new study is that poor, older teenagers are more likely to be overweight than their well-off counterparts. It found the prevalence of overweight was more than 50 percent higher in older teens living below the poverty line, compared to those living above the poverty line.

The number of overweight American teens has risen dramatically over the past 30 years. In the '70s and '80s, there was no difference at all.
The important factors that might contribute to teen overweight are physical inactivity, increasing consumption of sweetened beverages and skipping breakfast.

With the rise in the prevalence of overweight, health-care professionals are concerned that diseases such as type 2 diabetes, high blood pressure and sleep apnea will also dramatically increase and begin to affect younger and younger people.

To get a better idea of how many teens are overweight and what populations are most at risk, the researchers pooled data from four different nationally representative surveys that included more than 10,000 children between the ages of 12 and 17. Information was gathered on height, weight, physical activity, dietary habits and socioeconomic status.
The researchers didn't find any significant difference in the prevalence of overweight in young teens (12-14) based on income levels. However, the difference was clear in older teens (15-17). The rate of overweight in older adolescents from poor families was 23 percent, compared to only 14 percent for older teens from more affluent areas.