The study, published in The Journal of the American Medical Association, makes it clear that in the U.S, weight issues have become common for people from all backgrounds.
For instance, being overweight is more than twice as common for U.S. teens as it was 30 years ago, regardless of race, sex, or ethnicity. There is "no evidence that the trend is reversing," write Richard Miech, PhD, MPH, and colleagues.
Miech works in Baltimore at thedepartment of Johns Hopkins University's Bloomberg School of Public Health. His study tracks overweight status among U.S. adolescents aged 12-17 years from 1971-2004.
Family Income, Teens' BMI
The data, taken came from four national surveys, was based on BMI (body mass index), which relates height to weight. Overweight teens were those in the 95th percentile of BMI for their age and sex, according to the CDC.
The teens' height and weight were measured. Their parents or caretakers reported the family's total income.
The results show a steeper rise in the prevalence of overweight teens aged 15-17 years from families living in poverty. In 1999-2004, about 23% of those teens were overweight, compared with about 14% of those not living in poverty, the study shows.
That pattern wasn't seen in adolescents aged 12-14 years. Older teens often have more freedom in choosing their foods and activities, the researchers note.
Of course, it's possible for teens of any background to achieve and maintain a healthy weight.
Clues in the Data
Miech's study doesn't untangle all of the reasons why poverty and overweight status might be connected. But Miech and colleagues did find some clues in the data.
Teens aged 15-17 years living in poverty were more likely to drink sweetened beverages, be less physically active, and skip breakfast than those from wealthier families, the study shows.
Those habits might be areas for further study and intervention, the researchers note. They call for more work to monitor, detect, and address the factors that may affect weight for teens living in poverty.