Food Avoidance and Restriction in Anorexia Nervosa: Gaze Behavior During Preference Evaluations and the Willingness...

Anorexia Nervosa (AN) is a severe psychiatric disorder marked by excessive restriction and automatic avoidance of fat and high-caloric foods, driven by fear of weight gain and guided by negative encoding of some foods that are essential for health. These impairments seem to reflect a conflict between willingness-to-eat and fear of negative outcomes, leading to maladaptive decisions prioritizing hypocaloric foods.

We developed an experimental paradigm to investigate the link between these cognitive disturbances by monitoring gaze during three tasks evaluating the health, taste, and preference values of three food categories: hypocaloric, hypercaloric, and intermediate calorie foods. We evaluated the reject rate and quantity wanted of each food item to compose their meal. To consider different patients profiles, we applied this protocol to 67 subjects across two subtypes: AN-Restrictive (n = 37), and AN-Binge-Purge (n = 30) and 37 healthy controls.

Both AN subtypes showed lower hedonic ratings for high-calorie foods and strong correlations between taste and health perceptions (absent in controls), though AN-BP provided lower overall health ratings than AN-R. Eye-tracking revealed subtype-specific patterns: AN-BP exhibited reduced gaze on food images and increased non-stimulus area fixation during preference evaluations, while AN-R showed greater fixation on food names during willingness-to-eat decisions. Furthermore, presentation context modulated food selection in both patient groups: intermediate foods were preferentially chosen over hypercaloric alternatives but rejected in favor of hypocaloric options, demonstrating that choices are relative rather than absolute.

By shedding light on mechanisms of food restriction and avoidance, this study holds promise for refining therapeutic strategies; contextual manipulation of food choices may offer intervention potential with intermediate-calorie foods potentially serving as a bridge during nutritional rehabilitation.