BACKGROUND: Orthorexia Nervosa (ON) is defined as a pathological preoccupation characterized by obsessive beliefs and compulsive behaviors regarding 'pure' eating behaviors. Many scales have been established and display good results regarding reliability and validity measures, including but not limited to ORTO-R (revised version of ORTO-15), Eating Habits Questionnaire, Teruel Orthorexia Scale (TOS) and the Düsseldorf Orthorexia Scale (DOS). Among these, the DOS seems to be a promising measure for multiple reasons. The current paper aims to validate the DOS, a measure of ON, in a non-Western population of Lebanese adolescents. METHODS: This was a cross-sectional designed study, conducted between May and June 2020, which enrolled 555 adolescents (15-18 years old; 75.7% females). Due the coronavirus pandemic outbreak, the data were gathered through snowball sampling using an online questionnaire. The DOS, TOS and ORTO-R scales were used in this study to screen for orthorexic tendencies and behaviors. RESULTS: We tested four competing structural models of the DOS assessing its factorial validity. The results of the current investigation revealed that the one-factorial model is the best one to represent the structure of the questionnaire. We provided evidence for validity for the DOS through demonstrating that it correlates significantly with other measures of orthorexic behaviours (Teruel Orthorexia Scale and ORTO-R). Finally, we have gathered evidence that the orthorexic behaviours as measured by DOS are not associated with age (r = -.02; p = .589), household crowding index (r = .02; p = .578), and Body Mass Index (r = .04; p = .297). Yet, females as compared to males achieved higher scores (M = 20.07, SD = 6.38 vs M = 18.29, SD = 6.37; p = .005; d = .28). CONCLUSION: The Arabic version of the DOS seems to be a structurally valid and internally consistent questionnaire measuring orthorexic eating behavior in a sample of Lebanese adolescents. This tool may be useful for psychologists, psychiatrists, dietitians and other clinicians in the assessment and the treatment of the multidimensional nature of ON.

Rogoza, R., Hallit, S., Soufia, M., Barthels, F., & Obeid, S. (2021). Validation of the Arabic version of the Dusseldorf Orthorexia Scale (DOS) among Lebanese adolescents. Journal of Eating Disorders, 9(1), 130. https://doi.org/10.1186/s40337-021-00488-4

https://pubmed.ncbi.nlm.nih.gov/34656172/