Anorexia nervosa is a pattern of self-starvation brought about by fanatical dieting. It is most common among affluent, well-educated adolescent girls in developed countries, where the pressure to be slender is especially intense. To be diagnosed as anorexia, a girl must weigh at least 15 percent less than original body weight expected for her age and height; must show an intense fear of gaining weight; must show a disturbance in the way she experiences her body's weight, shape, or size; and must have missed at least three consecutive menstrual periods. The anorexic girl resembles a skeleton, with protruding ribs, a skull-like head, and clawlike hands.