Orthorexic eating behaviors are not all pathological: a French validation of the Teruel Orthorexia Scale (TOS)

As no French validated measurement tool distinguishing healthy orthorexia (HeOr) from orthorexia nervosa (OrNe) currently exists, this study aimed at examining psychometric properties of the French version of the Teruel Orthorexia Scale (TOS). A sample of 799 participants (Mean [SD] age: 28.5 [12.1] years-old) completed the French versions of the TOS, the Dusseldorfer Orthorexia Skala, the Eating Disorder Examination-Questionnaire, and the Obsessive-Compulsive Inventory-Revised. Confirmatory factor analysis and exploratory structural equation modeling (ESEM) were used. Although the bidimensional model, with OrNe and HeOr, of the original 17-item version showed an adequate fit, we suggest excluding items 9 and 15. The bidimensional model for the shortened version provided a satisfactory fit (ESEM model: CFI = .963, TLI = .949, RMSEA = .068). The mean loading was .65 for HeOr and .70 for OrNe. The internal consistency of both dimensions was adequate (alpha(HeOr) = .83 and alpha(OrNe) = .81). Partial correlations showed that eating disorders and obsessive-compulsive symptomatology measures were positively related to OrNe and unrelated or negatively related to HeOr. The scores from the 15-item French version of the TOS in the current sample appears to present an adequate internal consistency, pattern of associations in line with what was theoretically expected, and promising for differentiating both types of orthorexia in a French population. We discuss why both dimensions of orthorexia should be considered in this area of research. Plain English summaryOrthorexia ('right appetite', from the Greek) covers two dimensions: (1) orthorexia nervosa (OrNe), a strong preoccupation with healthy diet with negative emotional, cognitive, and/or social consequences while trying to approach this goal and when the eating behavior deviates from it, and (2) healthy orthorexia (HeOr), which can be defined as a healthy interest in diet, (self-assessed) healthy behavior with regard to diet and eating healthily as part of one's identity. OrNe is not yet indexed into mental disorder classifications. Some prominent measurement tools in the area of orthorexia present important limitations: it is unclear if they validly assess OrNe and they do not tap HeOr by design. To overcome these limitations, a promising self-reported instrument was developed: the Teruel Orthorexia Scale (TOS), a bidimensional questionnaire whose structure has been replicated in different samples. Our research based on 799 participants aimed to adapt this instrument in a French speaking population. The results revealed that the French version of the TOS is an empirically supported tool allowing to differentiate both forms of orthorexia (healthy and nervosa). It also suggests that OrNe is associated with psychopathological symptoms while opposite patterns were found with HeOr. We discuss the importance of measuring both orthorexia dimensions.