List the main categories of eating disorders and describe the approach used to treat eating disorders.

The main categories of eating disorders include anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS), which includes binge eating disorder. Individuals with AN have a fear of "fatness" and strive for extreme thinness and can do this through restricting food intake and/or excessive exercise. Individuals with BN also fear being overweight but experience an overwhelming feeling to consume excessive amounts of food. However, individuals with BN purge after consuming large quantities of food, exercise excessively, or abuse laxatives or enemas. Individuals with EDNOS can purge in the absence of binge-eating, chew and spit out food, or meet some but not all of the symptoms of AN or BN.