Adaptation and validation of the Spanish version of the ORTO-15 questionnaire for the diagnosis of orthorexia nervosa

The aim of this study was the validation and analysis of the psychometric properties of a Spanish translation of the ORTO-15 questionnaire; an instrument designed to assess orthorexia nervosa behavior. Four hundred and fifty-four Spanish university students (65% women) aged between 18 and 51 years (M = 21.48 +/- 0.31) completed the Spanish version of ORTO-15 and the Eating Disorders Inventory-2 (EDI-2). The Principal Component Analysis suggested a three-factor structure for the abbreviated 11-item version of the instrument. The internal consistency of the measurement was adequate (Cronbach's alpha = 0.80). The proposed test demonstrated a good predictive capacity at a threshold value of <25 (efficiency 84%, sensitivity 75% and specificity 84%). Our results support the psychometric properties of the proposed Spanish shortened-version of the ORTO-15 as being a reliable tool for assessing orthorexia nervosa. Its use is expected to greatly contribute to a better understanding of the impact of this disorder in Spain.