Structural validation of ORTO-11-ES for the diagnosis of orthorexia nervosa, Spanish version

PURPOSE: The ORTO-11-ES questionnaire is a tool to assess the pathological obsession displayed by some individuals regarding healthy eating. The aims of this study were (1) to confirm the factor structure of the Spanish version of ORTO-11-ES using confirmatory factor analysis (CFA) and (2) to examine the possible association between the ORTO-11-ES score, gender and body mass index (BMI). METHODS: The sample comprised 492 students from the University of Castilla la Mancha, Spain. Of these, 280 were women (56.9%). Participants were surveyed using the ORTO-11-ES questionnaire. RESULTS: The confirmatory factor analysis (CFA) supported the 11 elements and 3 domains of this tool as the better fitting model; for the Comparative Fit Index (CFI) and the Tucker–Lewis Index (TLI), the values were 0.94 and 0.91, respectively, and the Root Mean-Square Error of Approximation (RMSEA) was 0.058. The tendency towards orthorexic behavior is more associated with the female gender. The BMI had no influence on the tendency for ON. CONCLUSIONS: This study is the first attempt to confirm the three-factor structure of a Spanish version of the ORTO-15 questionnaire. These findings suggest that the ORTO-11-ES may be a valuable tool for identifying subjects with specific eating behavior patterns. This information may be useful for health professionals involved in the research, development and implementation of interventions catered to individuals suffering from this eating disorder. LEVEL OF EVIDENCE: Level V, descriptive cross-sectional study. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40519-018-0573-3) contains supplementary material, which is available to authorized users.