Exposure to binge food in bulimia nervosa: finger pulse amplitude as a potential measure of urge to eat and predictor of food intake.

The conditioning model of binge eating states that cues such as the sight, smell and taste of binge food prepare the binger's body for the intake of large amounts of food. The bodily preparations are supposed to be felt as an almost irresistible urge to binge. In the present study, the validity of the model was tested. Clinical binge eaters (bulimia nervosa patients) and healthy control participants were exposed to their most favourite food and physiological responding was measured. As predicted, the exposure increased physiological responding and led to more intense urge to eat, but no significant differences between the bulimics and the normal controls were found. For both groups, increased urge to eat appeared to be related to finger pulse amplitude (FPA), and both the FPA and the self-reported urge to eat predicted increased caloric intake during a subsequent taste test. It is concluded that changes in FPA might reflect classically conditioned bodily responses that prepare for eating.