Healthy orthorexia vs. orthorexia nervosa: Italian validation of the Teruel Orthorexia Scale (TOS)

Purpose: Orthorexia nervosa (OrNe) is a potentially pathological condition characterized by a fixation on healthy diet. An increasing number of studies have been conducted on this mental preoccupation, but the validity and reliability of some of the psychometric instruments employed in its assessment are still under debate. Among these measures, the Teruel Orthorexia Scale (TOS) seems to be promising, given that it allows to differentiate between OrNe and other non-problematic forms of interest with healthy eating, named as healthy orthorexia (HeOr). The aim of this study was to examine the psychometric properties of an Italian version of the TOS, by testing its factorial structure, internal consistency, test–retest reliability, and validity. Method: Through an online survey, we recruited 782 participants from different regions of Italy, asking them to complete the following self-report instruments: TOS, EHQ, EDI-3, OCI-R, and BSI-18. From the initial sample, 144 participants agreed to complete a second TOS administration 2 weeks later. Results: Data confirmed the validity of the 2-correlated factors structure of the TOS. The questionnaire also showed good reliability, both in terms of internal consistency and temporal stability. With regard to the TOS validity, results showed that OrNe was significantly and positively associated with measures of psychopathology and psychological distress, while HeOr showed no correlations or negative associations with the above-mentioned measures. Conclusion: Based on these results, the TOS can be considered a promising measure for the assessment of both pathological and non-problematic forms of orthorexic eating behavior also in Italian population. Level of evidence: Level V, descriptive cross-sectional study.