Dieting behaviors and nutrition can have an enormous impact on the gynecologic health of adolescents. Teenaged patients with anorexia nervosa can have hypothalamic suppression and amenorrhea. Approximately one half of adolescents with bulimia nervosa also have hypothalamic dysfunction and oligomenorrhea or irregular menses. In contrast, the obese adolescent with menstrual irregularity frequently has anovulation and hyperandrogenism, commonly referred to as polycystic ovary syndrome. Insulin resistance is thought to play a role in the pathophysiology of this condition. Obesity in early adulthood may increase the risk of menstrual problems and subfertiltiy. These reproductive health problems are likely to increase with the current trends of increasing fatness in the general population. Higher risks of infertility have been found in both overweight and underweight women. It is apparent that weight does have a role in fertility. Some females try to control their weight with eating disorders and this only causes other problems in their lives. The weight loss or gain is over powering to the neuroendocrine system and causes the menses to cease. It is usually the case that once the weight is regained, menses returns. Without the menses the woman is infertile until they return which is usually not until the weight changes.