Differences in salivary habituation to palatable foods in bulimia nervosa patients and controls

Bulimia nervosa (BN) patients have been shown to experience anomalous responses to food and food cues. We investigated the response to food over time by presenting repeated food cues and measuring changes in physiological (ie, salivation) and subjective responses.

Subjects were 18 BN women and 18 matched control women. Two palatable food stimuli, regular or frozen yogurt, that varied in macronutrient composition but had similar sensory characteristics, were presented to subjects repeatedly during a laboratory session. After two baseline salivation measures, subjects were presented with eight trials of one of the two yogurts. On Trial 9 a lemon juice dishabituator was presented, with the yogurt stimulus presented again at Trial 10.

We found that control subjects had decreased salivation after repeated food presentations. In comparison, BN subjects failed to show a decrease in salivation. The desire to binge increased over trials for the BN subjects, but remained stable for normals.

These data suggest that salivary habituation may be abnormal in BN patients.