Diets an unhealthy fix for teen weight concerns

By Anne Harding

NEW YORK (Reuters Health) - Teens who go on diets to drop some pounds are more likely to skip breakfast and binge eat -- which may at least partly explain why they put on more weight over time than their peers who don't diet, a new study shows.

The researchers set out to uncover the reasons why dieting by adolescents has been shown in previous studies to predict later weight gain.

The behaviors they identified, however, don't entirely answer the question, Dr. Dianne Neumark-Sztainer of the University of Minnesota in Minneapolis, the study's lead author, told Reuters Health.

It's possible, she explained, that people who are at greater risk of becoming overweight are also more likely to be dieters, although their initial weight was taken into account in the study's analysis.

Nevertheless, the findings show that dieting is a short-term fix that teens choose instead of longer-term, healthier -- and more effective -- strategies like eating more fruits and vegetables and getting more exercise, Neumark-Sztainer said.

"We really want to discourage teenagers from dieting," she added, noting that she and her colleagues previously found most teen dieters used unhealthy weight control strategies like smoking, fasting, and skipping meals.

For their study, published in the Journal of the American Dietetic Association, Neumark-Sztainer and her colleagues interviewed 2,516 teens in 1999 and again five years later.

At the earlier time point, 56 percent of girls reported dieting while 25 percent of boys said they had dieted at least once.

Five years later, female dieters were less likely to eat breakfast and were more likely to binge eat, and they had gained 0.69 more body mass index (BMI) points than their non-dieting classmates. Boys who dieted were more likely to binge eat, spent less time engaging in moderate to vigorous physical activity, and put on .77 more BMI points than boys who didn't try to control their weight by dieting.

The findings suggest, Neumark-Sztainer and her colleagues conclude, that kids who diet are in danger of developing unhealthy physical activity and eating behaviors.

"My advice to parents is to redirect their children's efforts away from dieting toward the adoption of eating and physical activity behaviors that they can engage in over the long term," she told Reuters Health.

Neumark-Sztainer has written a book for the parents of teens called "I'm, Like So Fat! Helping your teen make healthy choices about eating and exercise in a weight-obsessed world." She advised, "I encourage people to think less about weight, talk less about weight per se, and really place the emphasis on engaging in these behaviors for long-term health, of which a healthy weight will be one of the outcomes."

SOURCE: Journal of the American Dietetic Association, March 2007.