Behavioural and psychosocial aspects of obesity and its treatment.

This chapter emphasized new directions being pursued in the behavioural treatment of obesity. Behavioural weight-loss programmes are being strengthened by their increased emphasis on low fat intake and exercise, by more direct intervention on behavioural antecedents and consequences of eating, by the use of very low calorie diets (VLCDs) and by the adoption of a chronic disease model and the concomitant lengthening of treatment programmes. With these approaches, initial weight losses of 10-20 kg can be achieved, and maintenance of weight losses of 5-10 kg can be expected. Treatments may also be strengthened by the identification of subgroups of the obese. Recently, progress has been made in this area with the description of a subgroup of the obese who have severe problems with binge eating. Binge eating disorder has been proposed as a new diagnostic category for DSM-IV. From 20 to 45% of the obese who present for treatment suffer from such problems. Obese binge eaters have worse mood and more psychopathology than obese people who do not binge eat, and are more likely to drop out of behavioural weight-control treatments. Although binge eaters may regain weight faster than non-binge eaters, both short- and long-term weight loss of binge eaters and non-binge eaters appear quite similar. Treatments have been identified that show promise in ameliorating binge eating for these patients, but these treatments have not produced weight loss. Although there has recently been concern about the possible negative effects of dieting on mood state, participation in behavioural weight-loss programmes is not associated with worsening mood in obese patients. No psychological variables have distinguished obese from non-obese individuals. Nonetheless, there is substantial prejudice against the obese. Awareness of this prejudice can lead to more sensitive and appropriate treatments for the problem of obesity.