The purpose of this study is to investigate the effects of nutritional and hormonal factors on bone turnover and bone density in women with anorexia nervosa. One aim of the study will be to determine the time course and quantitative effects of short-term, low dose, rhIGF-I administration on bone turnover in estrogen-treated vs. nonestrogen- treated women with anorexia nervosa. The second aim is to investigate the long term effects of combined estrogen and rhIGF-I on bone density in anorexia nervosa; for this part of the study, anorectic subjects with established bone loss will be randomized to recieve one or both treatments for a period of nine months.