Eating disorders are often underdiagnosed. Orthorexia nervosa (ON), a new type of eating disorder, is defined as excessive preoccupation with healthy eating, causing significant nutritional deficiencies and social and personal impairments. The ORTO-15 is a 15-item instrument widely used to evaluate orthorexia nervosa. It was developed by Donini et al (2005) in Italian and has been translated and adapted in other languages. In this study, the validity and reliability of the Indonesian version of ORTO-15 were assessed. The Indonesian version of the instrument was then reviewed by experts after translation. The back-translation was assessed for consistency with the original instrument. The instrument was then statistically-tested for validity and reliability on 50 randomly selected subjects. The subjects were balanced in gender and the mean age was 19.4 + 0.8 years. The reliability was tested using Cronbach’s alpha. The validity was tested using Pearson's product-moment correlation and confirmatory factor analyses (CFA). The Pearson product moment verified good validity for the instrument (r = 0.369 – 0.881). CFA analyses confirmed good communalities (extraction > 0.5) and revealed three components construct (cumulative 73.5%). Reliability test confirmed that the instrument had good reliability (Cronbach's alpha = 0.915). The ORTO-15 Indonesian version is a valid and reliable instrument for the assessment of ON.
Reproducibility of Results ; Feeding and Eating Disorders