EFFECTS OF PRELOADS OF DIFFERING ENERGY AND MACRONUTRIENT CONTENT ON EATING BEHAVIOR IN BULIMIA-NERVOSA

Evidence suggests that bulimics demonstrate blunted satiety possibly d ue to repeated episodes of overeating. This suggestion was tested furt her by comparing responses to yogurt preloads differing in carbohydrat e and fat relative to a lower energy control yogurt in 12 bulimics and 12 age-and weight-matched controls. Participants were tested on three occasions at lunchtime. On each occasion, appetite and mood were rate d before and after receiving a lunch of raspberry yogurt (350 g). Cove rt manipulation of energy and nutrient content was achieved by matchin g the yogurts on sensory properties and formulating a control yogurt ( 161 kcal), a high-fat version (357 kcal: 65% calories from fat), and a high-carbohydrate version (357 kcal: 81% calories from carbohydrate). Although there were no differential effects of the preloads on intake of an ad libitum test meal given 5 hr later in either the control or bulimic groups, there were significant differences in test meal energy intake between groups. On average and with all conditions combined, b ulimics ate significantly fewer calories (775 +/- 167 kcal) than contr ols (1182 +/- 94 kcal) and consumed a greater percentage of calories f rom carbohydrate than controls. Bulimics restricted their intake relat ive to controls, and chose foods low in fat. This study provides furth er evidence of restricted eating in bulimia nervosa when the opportuni ty to purge is not available. Furthermore, the present study suggests that intake by bulimics is not influenced by nutrient content per se b ut by consideration of the caloric value of foods and the consequences of eating certain foods for weight control. (C) 1997 Academic Press L imited.