Amenorrhea in anorexia nervosa: examination of the critical body weight hypothesis.

In order to examine the relevance of the critical body weight hypothesis to menstrual regulation in anorexia nervosa, extensive physical, dietary, and behavioral assessments were made in 40 anorexia nervosa patients immediately before and after treatment, and at 3-month intervals up to 1 year posttreatment. Fifteen patients recovered menses; the body weights of these patients agreed with weights predicted by the critical body weight hypothesis. However, 12 patients with continuing amenorrhea had also achieved similar body weights. Clinical assessment showed that patients with continuing amenorrhea, both of normal and low weights, had significantly more "anorectic" attitudes and behaviors than the menstruating patients.