Caloric requirement for refeeding inpatients with anorexia nervosa: The contribution of anxiety exercise, and cigarette smoking

Refeeding inpatients with anorexia nervosa (AN) is costly, stressful, and can precipitate the refeeding syndrome. Caloric intake is usually increased gradually from a low starting point until a steady weight gain is achieved. There is no reliable equation that predicts the number of calories required for a weight gain. It was our clinical suspicion that anxiety, exercise, and cigarette smoking might increase the caloric need for refeeding. We conducted an observational cohort study of 17 females with AN admitted to an inpatient eating disorder unit for refeeding. We estimated the energy intake by observation, the caloric expenditure due to exercise with a triaxial accelerometer, the number of cigarettes smoked by history, and the anxiety by the Beck Anxiety Inventory (BAI). Neither anxiety, exercise, or cigarette smoking predicted the caloric requirement for refeeding, individually or in combination. Discussion: Our data suggest that the caloric requirement for weight gain during refeeding is not predicted by the patient's anxiety, exercise or smoking habits. The standard methods of estimating caloric requirements for refeeding remain indirect calorimetry and previous history.