Body composition changes during recovery from anorexia nervosa: comparison of two dietary regimes.

Twelve patients with anorexia nervosa were studied on the Clinical Research Center for periods of 15 to 58 days. Five patients were fed a diet providing 20% of energy from protein and seven patients were fed a diet with only 10% of energy from protein. These patients had a reduced lean body mass in addition to a loss of body fat, and during recovery about two-thirds of the weight gain was lean tissue. The average energy cost of the weight gain was 5.3 kcal/g. There was no significant difference between the two diets for elemental metabolic balance, changes in anthropometric measures, in weight gain, or in potassium-40 counts; nor was there any difference in the energy cost of weight gain, in the rise in basal metabolic rate, or the change in hematocrit, serum albumin, or cholesterol. However, blood urea nitrogen was higher in those patients who received the high protein diet. Satisfactory nutritional rehabilitation of patients with anorexia nervosa does not require a high protein diet.