Predictors of orthorexic behaviours in patients with eating disorders: a preliminary study

Background: The construct of orthorexia in eating disorders (EDs) has received very little attention despite clinical observations of a possible overlap between the two. The aim of this study was: 1) to assess orthorexic behaviours, eating disorder pathology and attitudinal body image in ED patients; 2) to identify possible predictors of orthorexia nervosa among ED patients. Methods: Fifty-two women diagnosed with EDs were recruited. Patients' assessment included the following: the ORTO-15 test (Polish version) for orthorexic behaviours; the Eating Attitude Test-26 (EAT-26) to identify ED symptoms; the Multidimensional Body-Self Relations Questionnaire (Polish version) to assess body image. Results: A latent class analysis was performed and differences between identified classes were assessed. The main differences concerned weight, ED pathology and orthorexic behaviours within the same group of ED patients. In order to examine predictors of orthorexia nervosa, we investigated a structural equation model, which excellently fitted to the data (chi(2)((17)) = 23.05; p = .148; CFI = .962; RMSEA = .08; p = .25; SRMR = .05). In ED patients, orthorexic behaviour was negatively predicted by eating pathology, weight concern, health orientation and appearance orientation. Conclusion: The assessment of the orthorexia construct in EDs may add to the paucity of studies about this issue and may help to clarify the relationship between the two. Differences and similarities seem to exist between these disorders, and may benefit from specific treatment approaches. Moreover, these preliminary findings open tracks for future research in the field of the psychology of eating.