Hedonic response to sucrose solutions and the fear of weight gain in patients with eating disorders

Previous research has shown that patients with bulimia nervosa (B), anorexia nervosa. restricting type, or restrictive-anorectic (RA), and anorexia nervosa, binge eating, purging type, or anorectic-bulimic (AB) exhibit a reduced hedonic response to sucrose compared with control subjects. We hypothesized that this response could be linked to an excessive fear of weight gain rather than a decreased ability to experience pleasure. We therefore compared the hedonic responses to sucrose solutions in B. RA and AB women (n = 20/group) in two different conditions: sucrose solution swallowed vs. sucrose solution spit. Under double-blind conditions and according to a Latin square design, patients received sucrose in solution (0, 5, 10, 20, and 40%) and rated each concentration for pleasantness on a nine-point scale. The two test conditions were randomly administered. The threshold concentration of sweet taste perception was also assessed, and the subjects filled out Chapman's Social and Physical Anhedonia Scale, The hedonic response to sucrose adjusted for the sweet taste perception threshold was significantly lower in the 'swallow' than in the 'spit' condition. There was a significant effect of sucrose concentrations as well as a significant condition by concentration interaction. When 'fear to swallow' sucrose solution responses were included as a covariate, the significant difference between the conditions of 'swallow' or 'spit' disappeared. but there was a significant concentration by condition by fear to swallow interaction and an almost significant covariate effect. When 'Drive for Thinness' on the Eating Disorder Inventory was included as a covariate, similar results were obtained. Social Anhedonia but not Physical Anhedonia correlated positively with 'Drive for Thinness' and 'fear of swallowing sucrose solutions', and correlated inversely with maximal hedonic response to the 'swallow' condition. 'We conclude that the hedonic responses to sucrose in patients with eating disorders are decreased when solutions are swallowed. This may reflect excessive fear of gaining weight rather than decreased ability to experience pleasure'. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.