For a better differential diagnosis of eating disorders, it is necessary to investigate their subtypes and develop specific assessment tools to measure their specific symptoms. Orthorexia nervosa is an alleged eating disorder in which the person is excessively preoccupied with healthy food. The ORTO-15, designed by Donini and colleagues, is the first and only at least partially validated instrument to measure this construct. The aims of the present study were to examine the psychometric properties of its Hungarian adaptation (ORTO-11-Hu), and to investigate its relationship to food consumption and lifestyle habits in order to contribute to a better description of the phenomenon.
The ORTO-11-Hu, a lifestyle habits questionnaire, a food choice list indicating foods the participants choose to consume, and ten additional orthorexia-related questions were administered to a group of 810 Hungarian participants (89.4% female) aged between 20 and 70 (M = 32.39 ± 10.37 years).
Confirmatory factor analysis suggested a single factor structure for the 11-item shortened version of the instrument. Internal consistency of the measure was adequate (Cronbach's alpha = 0.82). No significant differences were found between males and females on the ORTO-11-Hu. Age and body mass index were significantly associated with a tendency towards orthorexia nervosa. Additional orthorexia-related features were significantly correlated with ORTO-11-Hu scores: orthorexia nervosa tendency was associated not only with healthier food choices (eating more whole wheat cereals, less white wheat cereals, more fruit and vegetables) but with shopping in health food stores, as well as with some healthy lifestyle habits (more sports activity, specific dietary behaviors, and less alcohol intake). Individuals with higher orthorexia nervosa tendency also reported a greater tendency to advocate their healthy diet to their friends and family members.
These results provide evidence for the reliability of ORTO-11-Hu and some support for the construct validity of the instrument. The present study also contributes to the establishment of (diagnostic) criteria for this new subtype of eating disorders.