Body mass index moderates gaze orienting biases and pupil diameter to high and low calorie food images

The primary goal of this study was to examine eye gaze behavior to different kinds of food images in individuals differing in BMI status. Eye-tracking methods were used to examine gaze and pupil responses while normal weight and overweight women freely viewed pairs of different food images: high calorie sweet foods, high calorie savory foods, and low calorie foods. Self-report measures of hunger, state and trait cravings, and restrained eating were also obtained. Results revealed orienting biases to low calorie foods and decreases in pupil diameter to high calorie sweet foods relative to low calorie foods in the overweight group. Groups did not differ in the average amount of time spent gazing at the different image types. Furthermore, increased state cravings were associated with larger pupil diameters to high calorie savory foods, especially in individuals with lower BMIs. In contrast, restrained eating scores were associated with a decreased orienting bias to high calorie sweet foods in the high BMI group. In conclusion, BMI status appears to influence gaze parameters that are less susceptible to cognitive control. Results suggest that overweight individuals, especially those who diet, have negative implicit attitudes toward high calorie foods, especially sweets.