Food Categorization Performance and Strategies in Orthorexia Nervosa

Orthorexia nervosa (ON) is an obsession with healthy eating and is notably characterized by food hyper-selectivity with the exclusion of food considered unhealthy. The cognitive mechanisms that underlie this type of food selectivity remain poorly understood. Recent research on anorexia nervosa, which overlap with ON traits, has revealed specific categorization performance (i.e., accuracy in discriminating between food categories) and strategies (tendencies to avoid one type of error over another) as well as categorization flexibility impairments in subjects suffering from anorexia nervosa. The present study includes three experiments that investigated food categorization according to ON traits.

Experiment 1 explored subjects’ abilities to categorize foods as healthy or unhealthy according to ON traits. Experiment 2 investigated subjects’ cognitive flexibility according to ON traits in the food domain. Experiment 3 tested subjects’ strategies using the signal detection theory framework, according to ON traits. The three experiments were conducted in France and replicated in Quebec.

Although the results did not allow us to conclude whether the ON scores affected the subjects' performance or cognitive flexibility, the results did reveal significant effects of ON scores on the subjects’ strategies when categorizing food as healthy or unhealthy, reflecting the fear of mistaking unhealthy foods for healthy ones when subjects exhibited high ON scores.

The findings challenge the standard way to define ON and pave the way for future research on emotional distress about food in subjects with high ON scores.