Average total energy expenditure in anorexia nervosa, bulimia nervosa, and healthy young women.

The double-labeled water method was used to measure average daily total energy expenditure (EE) in 11 healthy normal-weight women classified as unrestrained eaters, in 8 patients with anorexia nervosa, and in 8 patients with bulimia nervosa. The body mass index was 20.0 +/- 1.3 kg/m2 in the control group, 15.2 +/- 5.6 kg/m2 in the anorectic groups, and 19.7 +/- 1.9 kg/m2 in the bulimic group. EE was measured over a 2-week period during which weight remained constant in all groups and was 2357 +/- 504 kcal/day for the controls, 2510 +/- 920 kcal/day for the bulimics, and 2899 +/- 656 kcal/day for the anorectics. Differences were not significant among groups. Physical activity was recorded in diaries by all subjects. Anorectic patients showed significantly more activity than all other groups. The data suggest that EE is high in anorectic patients as a consequence of physical activity.