Carbohydrate oxidation rates in patients with anorexia nervosa.

Twenty-one hospitalized anorexia nervosa (AN) patients underwent a 50-g glucose challenge. All patients were then fed for 10 days and divided into two groups based on weight gain. Group AN-a (n = 10) gained little or no body weight over the 10-day period, whereas the second group, AN-b (n = 11), did gain weight during the same period. A third group of normal women (n = 10) served as control subjects (NC). Following ingestion of 50 g of glucose, group AN-a showed virtually the same nonprotein respiratory quotient (NPRQ) response as group NC. Group AN-b showed significant increases in basal and glucose-stimulated NPRQ and carbohydrate oxidation rate responses compared with group NC. Serum insulin responses in both AN groups were lower than those of group NC. These results indicate that insulin sensitivity in both liver and muscle may be increased in AN patients, and that refeeding tends to increase body weight rapidly in some patients due to this mechanism.