Newswise — A new study of teenagers has found that the same risk factors are associated with both being overweight and with disordered eating behaviors like binge eating and using diet pills. Moreover, food-related problems are extraordinarily common among urban teens — affecting 44 percent of adolescent girls and 29 percent of boys.

The study also suggests that teasing teens about weight is no joke, especially when the teasing comes from family.

More than one-third of the overweight girls in the study engaged in what the researchers called "extreme weight control behaviors," like vomiting or taking diet pills or laxatives in an attempt to lose weight. "We usually look for these behaviors in very thin girls, but here we see a very high prevalence in overweight girls," said lead author Dianne Neumark-Sztainer, Ph.D., professor of public health at the University of Minnesota.

The researchers looked at 2,516 adolescents, primarily from inner city schools, first in 1998 or 1999, and again five years later. They asked teens about their dietary practices, exercise, exposure to weight-related media messages (such as diet advice), family meals and about whether peers or family members had teased them about their weight. About one-quarter of the teens were overweight.

The study appears in the November issue of the American Journal of Preventive Medicine.

"It is common lore that eating disorders and obesity are separate problems and that intervening with obesity intensifies concerns about weight and makes eating disorders worse," said Kelly Brownell, Ph.D., director of the Rudd Center for Food Policy and Obesity at Yale University. "This study shows that some common factors may create vulnerability to or protection against both problems," said Brownell, who was not associated with this research.

A history of teasing about being fat was one of the strongest predictors of risk for being overweight and extreme dieting— and taunts from family seemed to be worse than teasing by peers. When family members teased teens about weight, it doubled their risk of being overweight at the second survey. Although this kind of study cannot prove that the link is causal, it suggests that even light-hearted joking about weight at home could be problematic.

Eating together as a family and a sense of connection to family were protective, however. "Most families where there is weight-teasing are not abusive. They just don't realize how hurtful it is," said Neumark-Sztainer, who has written a book for parents to help with weight-related problems. "These findings show that your home needs to be a safe haven."

She added, "We have seen over the years that it does not work to make people feel worse about their bodies. The data are striking — talking about weight, worrying too much about diet, focusing on it increases risk not only of eating disorders, but also of being overweight." Instead, she suggests modeling and positive encouragement of healthy behavior like making better food choices and exercising — and unconditional love, regardless of weight.

American Journal of Preventive Medicine: Contact the editorial office at (858) 457-7292 or [email protected]

Neumark-Sztainer D, et al. Shared risk and protective factors for overweight and disordered eating in adolescents. Am J Prev Med 33(5), 2007.

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American Journal of Preventive Medicine (Nov-2007)