Differences in attention to food and food intake between overweight/obese and normal-weight females under conditions of hunger and satiety

Starting from an addiction model of obesity, the present study examined differences in attention for food-related stimuli and food intake between overweight/obese and normal-weight women under conditions of hunger and satiety. Twenty-six overweight/obese (BMI: 30.00 +/- 4.62) and 40 normal-weight (BMI: 20.63 +/- 1.14) females were randomly assigned to a condition of hunger or satiety. Three indexes of attention were employed, all including pictures of food items: an eye-tracking paradigm (gaze direction and duration), a visual probe task (reaction times), and a recording of electrophysiological brain activity (amplitude of the P300 event-related potential). In addition, the acute food intake of participants was assessed using a bogus taste task. In general, an attentional bias towards food pictures was found in all participants. No differences between groups or conditions were observed in the eye-tracking data. The visual probe task revealed an enhanced automatic orientation towards food cues in hungry versus satiated, and in overweight/obese versus normal-weight individuals, but no differences between groups or conditions in maintained attention. The P300 amplitude showed that only in normal-weight participants the intentional allocation of attention to food pictures was enhanced in hunger versus satiety. In hungry overweight/obese participants, the P300 bias for food pictures was not clearly present, although an increased food intake was observed especially in this group. In conclusion, various attention-related tasks yielded various results, suggesting that they measure different underlying processes. Strikingly, overweight/obese individuals appear to automatically direct their attention to food-related stimuli, to a greater extent than normal-weight individuals, particularly when food-deprived. Speculatively, hungry overweight/obese individuals also appear to use cognitive strategies to reduce a maintained attentional bias for food stimuli, perhaps in an attempt to prevent disinhibited food intake. However, in order to draw firm conclusions, replication studies are needed. (C) 2009 Elsevier Ltd. All rights reserved.