Salivary habituation and satiety in bulimia nervosa patients and normal controls

Binge eating in bulimia nervosa (BN) patients has been postulated to be a disorder of satiety. Our laboratory has been studying the development of satiety by presenting repeated food cues, and measuring changes in physiological and subjective responses related to satiety. The present study was designed to evaluate differences between BN patients (n = 16) and normal controls (n = 16) in their salivary and subjective habituation to two palatable food stimuli, regular or frozen yogurt, which varied in the macronutrient composition, but had similar sensory characteristics. After 2 baseline salivation measures, subjects were presented eight habituating trials of the respective yogurts. On Trial 9 a lemon juice dishabituator was presented, with the habituating stimulus presented again at Trial 10. Results showed a significant interaction of diagnosis by trials for salivation. Control subjects showed a decrease in salivation with repeated food presentations, while BN subjects did not show a decrease in salivation. These data suggest that salivary habituation, and perhaps mechanisms related to satiety are impaired in BN patients. Possible explanations for these results are explored.