Relationship of premorbid mass and energy intake to increase of body mass during the treatment of anorexia nervosa.
Dietary intakes were compared in two groups of patients with anorexia nervosa, those who had earlier been "heavy" (n = 27, peak body mass = 65.0 +/- 7.5 kg) and those who had always been "light" (n = 25, peak body mass = 51.5 +/- 7.3 kg). Both groups were initially given a food intake of 7.5 MJ per day, and this was increased as needed to yield a controlled 1-2 kg per week increase of body mass. Body mass was restored most rapidly in the patients who reached the lowest weights, whether the classification was based upon the lowest body mass observed during the illness (gain in weeks 0-7, p < .002) or the body mass on admission to hospital (gain in weeks 0-14, p < .02, weeks 7-14, p < .01). Classifying patients in terms of their peak premorbid mass, the light group consumed food energy at a faster rate than the heavy group over the first 7 weeks of hospital treatment (p < .008), but nevertheless they did not gain more weight. Food intake reached a plateau in both groups between weeks 7 and 14 of treatment, although the light group was still consuming more energy than the heavy subjects (p < .005). Prospective observations on two light and two heavy patients confirmed both the time course of weight gain and the greater energy needed for a given increase of body mass in light patients. It is suggested that during the early stages of recovery from anorexia nervosa, energy utilization is more efficient in the heavier patients. However, it seems more difficult to sustain a high food intake in such patients, possibly because they fear a return to obesity.
Shinder
S E
SE
Graduate Department of Community Health, University of Toronto, Ontario, Canada.
Shephard
R J
RJ
D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000534:rehabilitation*; D015992:Body Mass Index; D002032:Bulimia / Q000534:rehabilitation*; D004435:Eating; D004734:Energy Metabolism; D001068:Feeding and Eating Disorders / Q000534:rehabilitation*; D006753:Hospital Records; D006760:Hospitalization; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012189:Retrospective Studies; D015430:Weight Gain