What Is It?
Anorexia nervosa is an eating disorder that affects about 1 in 100-200 girls or women in the United States. A person with this disorder limits eating and by definition weighs at least 15% less than his or her ideal weight.
At least 90% of cases are in women and the disorder usually begins in adolescence. The weight loss may delay the onset of menstruation or stop it once it has started, Anorexia nervosa rarely occurs before puberty or after age 40. And, although relatively rare, it can occur in men.