A tasting experiment comparing food and nutritional supplement in anorexia nervosa

Anorexia nervosa (AN) is a severe psychiatric disorder leading to life-threatening emaciation. Weight restoration is crucial in treatment but few data are available on how to achieve it. Nutritional supplements are needed in treatment but patients' preferences about natural versus medical foods and their gustatory/hedonic perception are unclear. We aimed to measure disgust and reward-based eating in AN and to assess psychological, interoceptive awareness-related, behavioral, and hedonic aspects comparing natural versus medical food. Thirty-three inpatients with AN and 39 healthy controls (HCs) were recruited and received 50 ml of either apricot juice or nutritional liquid supplement with apricot flavor on two consecutive days. Disgust, reward-based eating, and eating psychopathology were evaluated. Visual Analogue Scales measuring anxiety, hunger, confusion about internal states, need for over-exercise, restraint, and satiety were completed before and after the experiment. Disgust and hedonic responses were measured after the experiment. Patients with AN reported preserved disgust sensitivity and higher reward-based eating drive. When compared to HCs, inpatients with AN reported higher scores on anxiety, hunger, confusion about internal states, urge to over-exercise, urge to eating restraint, and satiety before and after the tasting experiment. The supplement slightly increased patients' anxiety with HCs reporting the same trend. Still, patients reported more food-related disgust after the supplement but their overall hedonic evaluation was similar for both conditions. Also, anxiety, confusion about internal states, and urge to over-exercise and restraint did not significantly increase after consuming either food. Therefore, if we take into account patients’ level of heightened satiety and suppressed hunger, supplements could be helpful for patients with severe AN since greater energy intakes could be provided with only small volumes of food and little changes of eating concerns.