Anorexia Nervosa:An eating disorder characterized by weight loss or lack of appropriate weight gain in growing children; difficulties maintaining an appropriate body weight for height, age, and stature; and, in many individuals, distorted body image. People with anorexia generally restrict the number of calories and the types of food they eat. Some people with the disorder also exercise compulsively, purge via vomiting and laxatives, and/or binge eat.