Issue 177 Item 6 Dieting Promotes Weight Gain in Children

Children who diet to control their weight may actually gain weight in the long run.

The weight gain might be because they resort to binge eating, according to a report in the October issue of Pediatrics.
"Although medically supervised weight control may be beneficial for overweight youths, our data suggest that for many adolescents, dieting to control weight is not only ineffective, it may actually promote weight gain," Dr. Allison E. Field of Children’s Hospital in Boston and colleagues report.

The prospective study included 8203 girls and 6769 boys who were between the ages of 9 and 14 years old in 1996. The subjects completed two or more annual questionnaires between 1996 and 1999, and annual assessments regarding dieting, binge-eating and dietary intake were performed.

At baseline, 25.0% of the girls and 13.8% of the boys were infrequent dieters and 4.5% and 2.2%, respectively, were frequent dieters. The percentage of dieters among the girls increased over the study period, Dr. Field’s group reported. Binge-eating was more common among the girls, but it was associated with attempts to control weight in both sexes.

"During the 3 years of follow-up, dieters gained more weight than nondieters," they report. "Among the girls, frequency of dieting was positively associated with increases in age- and sex-specific z scores of BMI."

Several possible mechanisms may explain these findings, the researchers note. Dieting may increase metabolic efficiency, leading to the need of fewer calories to maintain weight.

Restrictive diets may also be maintained for relatively short periods. This may result in a cycle of restrictive dieting followed by overeating and bingeing, leading to weight gain. The finding in the current study that dieters were more likely to binge-eat than were nondieters supports this hypothesis.

Dr. Field’s group suggests that young people who are not severely overweight be encouraged to develop a modest and sustainable weight control approach that includes physical activity and does not involve severe restriction of calories or dietary components, such as fat. Pediatrics 2003;112:900-906.