Dieting Not Linked to Eating Disorders in Overweight Adults

Dieting, defined as the intentional and sustained restriction of caloric intake to reduce body weight or change body shape, does not appear to cause eating disorders or other psychological dysfunction in overweight and obese adults. The National Task Force on Prevention and Treatment of Obesity reached this conclusion as a result of a comprehensive literature review. Empirical studies evaluating weight loss treatment, very low calorie diets (VLCDs), weight cycling, prescription medications, and “nondieting” approaches do not support concerns that dieting may lead to or worsen eating disorders in overweight and obese adults, the task force reported in the September 25, 2000 Archives of Internal Medicine.

Such concerns about the relationship of dieting to eating disorders originated with an experiment conducted during World War II with normal weight subjects. Young men who ate a semi-starvation diet for 6 months developed negative emotional reactions including depression, irritability, and anger, and a few engaged in binge eating behavior that persisted even after they had free access to food. These results are often assumed to apply to overweight and obese adults, among whom binge eating disorder (BED) is the most common eating disorder. A key question for the task force was whether weight-loss treatment leads to increased binge eating in these individuals.

Obese adults enrolled in weight-loss programs that focus on moderate energy restriction, increased physical activity, and group or individual counseling are unlikely to develop binge eating problems, concluded several studies. In contrast, the data suggest that this type of treatment reduces binge eating in those who had recurrent binge eating episodes prior to program enrollment.

Several studies looked at the effect of VLCDs ranging from 400 to 800 calories per day on the development of binge eating as a compensatory response to psychological or physiological deprivation. Two studies reported no increase in binge eating among those who were classified as non-binge eaters prior to treatment, and found improvement in eating behavior among binge eaters. One investigation found an increase in self-reported binge eating behavior in previous non-binge eaters after 12 weeks on a liquid diet, although caloric content of these self-reported binge episodes was not collected.

Several cross-sectional studies found a consistent, positive link between weight cycling and binge eating. It is unclear from these reports, however, if weight cycling caused the binge eating or if binge eaters were more likely to weight cycle. One study found that weight-cycling women with BED reported greater psychological distress, depression, and lower self esteem than weight cyclers without BED. Overall, weight cycling does not seem to be associated with clinically significant psychopathologic conditions.

Does dieting and weight loss in overweight and obese adults cause psychological problems, as early studies suggest? Numerous studies conducted over the last 25 years show reductions in symptoms of depression and anxiety—or at least no worsening of these conditions—in obese patients undergoing supervised weight loss treatment. Almost half of the men and women enrolled in the National Weight Control Registry (a registry of people who have lost at least 30 pounds and maintained the loss for more than a year) lost weight on their own without a formal program. Measures of mood, distress, restraint, disinhibition, binge eating, and purging among these individuals indicate that many people who have lost weight through a variety of methods do not experience significant psychological distress or disordered eating behaviors.

“Nondieting” approaches to weight control have become more common in response to the generally poor results of long-term weight-loss programs. These approaches focus on helping people recognize and eat in response to the body’s “natural” hunger and satiety signals, and increase self-esteem and positive body image through self-acceptance. Nondieting approaches appear to result in improved self-esteem, mood, and eating behavior—changes that are comparable to those of traditional weight loss treatments. However, these approaches do not seem to lead to clinically significant short- or long-term weight loss or improvement in weight-related illnesses like hypertension or type 2 diabetes.

Based on these studies, the task force concluded that dieting does not induce eating disorders or other psychological dysfunction in overweight and obese adults. It also found that such concerns should not discourage overweight adults from eating fewer calories and being more active to lose a moderate amount of weight or prevent additional weight gain.

The full report appears in the September 25, 2000 issue of Archives of Internal Medicine and is accessible to registered users at http://archinte.ama-assn.org. s