Recent studies on the epidemiology of anorexia nervosa, bulimia nervosa, binge-eating disorder, and eating disorders in special populations and in other cultures are reviewed. In addition, studies on the epidemiology of dieting behavior and longitudinal studies of the outcome of dieting behavior are reviewed. It is concluded that anorexia and bulimia nervosa are uncommon disorders but probably have increased in incidence in recent years. However, they are one of the most common psychiatric disorders to affect young women in the west. Dieting behavior is a major risk factor in the pathogenesis of the eating disorders. The prevalence of the eating disorders in a given community is, therefore, correlated with the prevalence of dieting behavior in the community.