Influence of Cognitive Biases in Visual Evaluation of Food Amount in Patients Affected by Eating Disorders

Abstract

We analyzed the influence of perceptive, cognitive, and emotional factors in the evaluation of food amounts among patients affected by Anorexia Nervosa, Bulimia Nervosa, and Binge Eating Disorder. No perceptive bias has been found, but cognitive and emotional biases seem to influence their evaluations. Anorexic subjects share the tendency to underestimate the number of presented items with the general population. Moreover, they tend to exaggerate the size of food, perceiving it as bigger than the control subjects do. Bulimic patients base their perception of binging on the type of food consumed, rather than basing it on the amount. Consumption of even small amounts of forbidden food may lead them to perceive their meal as a binge. Patients affected by Binge Eating Disorder report that their typical and largest-ever portions of foods are larger in a very significant way compared with those of the control subjects. Biases in evaluation of food amounts are also present in the general population and among obese subjects not affected by any eating disorders and can contribute towards gaining weight. To deal with this impairment several tools have been developed over the last few years. The last part of the chapter reviews the efficacy of these instruments to improve the subjects’ ability in evaluating the amount of their own food intake.