BACKGROUND Disturbed eating and severe caloric restriction are characteristic features of patients with anorexia nervosa (AN). Despite the importance of eating behavior in the presentation of AN, there have been relatively few objective laboratory studies of eating behavior among persons with eating disorders. OBJECTIVE The purpose of the study was to obtain objective measures of eating behavior among patients with AN before and immediately after weight restoration and to compare those measures with measures among control subjects. METHODS Twelve patients hospitalized for AN and 12 control subjects participated in the study. Eleven of the 12 patients were retested at 90% of ideal body weight. RESULTS The average meal consumption was 103.97 +/- 102.08 g for patients at low weight and 178.03 +/- 202.97 g after weight restoration (NS). Control subjects consumed significantly more than did AN patients at both time points, and the average meal size was 489.58 +/- 187.64 g. Patients showed significant decreases in psychological and eating-disordered symptoms after weight restoration. CONCLUSIONS These data suggest that patients with AN show a persistent disturbance in eating behavior, despite the restoration of body weight and significant improvements in eating-disordered and psychological symptoms.