Each year millions of people in the United States are affected by serious and sometimes life-threatening eating disorders. The vast majority - more than 90% - of those afflicted with eating disorders are female adolescents and young adult women.

Eating is controlled by many factors, including appetite, food availability, family, peer, and cultural practices, and attempts at voluntary control. Dieting to a body weight leaner than needed for health is highly promoted by current fashion trends, sales campaigns for special foods, and in some activities and professions.

Eating disorders involve serious disturbances in eating behavior, such as extreme and unhealthy reduction of food intake or severe overeating, as well as feelings of distress about body shape or weight.

Eating disorders are not due to a failure of will or behavior; rather, they are real, treatable medical illnesses in which certain maladaptive patterns of eating take on a life of their own. The main types of eating disorders are anorexia nervosa and bulimia nervosa. A third type, binge eating disorder, has been suggested but has not yet been approved as a formal psychiatric diagnosis. Eating disorders frequently develop during adolescence or early adulthood, but some reports indicate their onset can occur during childhood or later in adulthood.