The moderating role of obsessive-compulsive symptoms and the mediating role of eating attitudes in the relationship between attentional bias and orthorexia nervosa tendency: An eye-tracking study

Orthorexia Nervosa (ON) is characterized by an excessive preoccupation with healthy eating and rigid dietary behaviors. Although it is not yet included in diagnostic manuals, ON has increasingly attracted clinical and academic attention. The overlap between ON, eating disorders (ED), and obsessive-compulsive disorder (OCD) has sparked ongoing debates regarding its classification. In this context, it is crucial to examine not only the behavioral features of ON but also its cognitive correlates. This study aimed to investigate the relationship between ON tendency and attentional bias through the mediating role of eating attitudes and the moderating role of obsessive-compulsive symptoms using an experimental eye-tracking method. The study consisted of two phases. In the screening phase, 347 healthy adults without clinical diagnoses completed the ORTO-11, the Eating Attitudes Test Short Form (EAT-26), and the Maudsley Obsessive-Compulsive Inventory (MOCI). In the experimental phase, two groups were formed based on high (n = 17) and low (n = 17) ON tendencies. Participants were shown 30 pairs of images comprising healthy, unhealthy food and neutral object stimuli, previously selected through a pilot study, and their eye movements were recorded for 8 seconds during the presentation of each stimulus pair. Attentional bias was evaluated across four components: first fixation direction/duration, total fixation duration, total fixation count, and run count between areas of interest. Hayes' PROCESS Model 5 was used to test the mediating role of eating attitudes and the moderating role of obsessive-compulsive symptoms in the relationship between ON tendency and attentional bias. In light of the analyses conducted during the screening phase, the findings obtained from the experimental phase revealed that orthorexic tendencies significantly and negatively predicted eating attitudes across all attentional bias parameters. However, the mediating and moderating effects of this relationship varied depending on the attentional parameters and the type of stimuli. No significant effect was found in the direction or duration of the first fixation; however, patterns indicative of attentional avoidance emerged in total fixation duration and count for certain types of stimuli, regardless of group differences. The number of transitions between areas of interest did not show a significant effect. In conclusion, this thesis suggests that orthorexia nervosa may represent a cognitive construct that not only influences eating attitudes but also impacts attentional processes and their associations with psychopathological structures, thereby contributing to theoretical discussions in the field. Keywords: Orthorexia Nervosa, Attentional Bias, Eating Attitudes, Obsessive-Compulsive Symptoms, Eye-Tracking