Sample and procedure
The study protocol was approved by the Ethics Committee of Semmelweis University (registration number 4498–0/2011-EKU; 410/PI/11). Participants were recruited from different universities in Hungary: students from Semmelweis University, Eötvös Loránd University, the University of Pécs, and the University of Debrecen. The data were collected via internet using the online test battery developed by the authors. Participants received the link to the research called ‘Nutrition and health’ in an email from the secretary at each university. In total, 810 individuals participated in the study (724 women, 86 men; 89.4% vs. 10.6%). The mean age of the respondents was 32.39 ± 10.37 years (31.48 ± 11.68 for males and 30.38 ± 10.20 for females). Body-mass index of the participants ranged between 14.88 and 56.06, with a mean of 23.20 ± 4.89.
The majority of participants comprised students from the following areas: dietetics (N = 69, 8.5%), medicine (N = 107, 13.2%), other health-related professions (nursing, physiotherapy, midwifery, optometry, physical education, and sport sciences; N = 240, 29.6%), and from other fields (sociology, social work, teaching; N = 33, 4.1%). Other participants included graduated professionals: dieticians (N = 26, 3.2%), medical doctors (N = 18, 2.2%), other healthcare professionals (N = 55; 6.8%), and non-healthcare professionals (N = 262, 32.3%).
All instruments were administered online in order to reach as many participants as possible. Participants completed an informed consent form, entered demographic information, filled in the Hungarian translation of the ORTO-15 and a checklist of food choices, and several ON-specific questions developed for the purpose of this study – based on the clinical experiences and observations from other authors [1, 2, 7]. Finally, participants were asked about their lifestyle (sports activity, dieting) and other foodstuff consumption habits (nutritional supplements, medication, alcohol, drugs, and smoking).
ORTO-15 is a measure instrument for ON comprising 15 multiple-choice items . This instrument is based on Bratman’s orthorexia model combined with MMPI obsessive-phobic personality trait questions [1, 9]. ORTO-15 is a self-report questionnaire with a 4-point Likert-scale (always, often, sometimes, never). The items address the selection, preparation, consumption, and effect of, and attitude towards presumed to be healthy food. The original test authors assumed three underlying factors: the cognitive-rational (items 1,5,6,11,12,14), the clinical (items 3,7,8,9,15) and the emotional (items 2,4,10,13) components of ON . The authors also tested the efficacy, sensitivity, specificity, positive and negative predictive value of three different threshold values for ORTO-15: <35, <40, and <45. Compared to the other two cutoff points, 40 (lower scores refer to more ON features) was considered to be the most appropriate for distinguishing between individuals with and without ON. In one sample, this cutoff had 73.8% efficacy, 55.6% sensitivity, 75.8% specificity, 20.5% positive predictive value, 93.8% negative predictive value; while in another sample it showed 75% efficacy, 100% sensitivity, 73.6% specificity, 17.6% positive predictive value and 100% negative predictive value .
For developing the Hungarian version of the ORTO-15, the first and the third author of the present study translated ORTO-15 into Hungarian. No new expressions were added nor were changes made to the original structure. The final version was created by using the expert opinions of two clinical psychologists. A back translation was conducted by an independent bilingual translator, and was compared to the original test by yet another professional; no significant changes were necessary. The final version of the scale was administered to 20 people to evaluate the clarity of the items.
Participants were asked about their sports activity, dietary restrictions, caffeine, alcohol, drug, cigarette, medication, and nutritional supplement use. Frequency of sports activity was assigned to the following categories: do not engage in any sport, casually, regularly as a hobby, compete regularly. Smoking status was coded as current, former, and nonsmoker. Alcohol, caffeine, medication, and nutritional supplement use were addressed with yes/no type questions.
Food choice list
Individuals were asked about the type of foods they usually eat. Food categories were developed by a dietician based on the nutrition pyramid . Participants rated the frequency of their consumption of given food types. The food choice list contained the following food categories: whole wheat bread, white bread (rated on a 3-point scale: daily, weekly, monthly or rarely), and vegetables plus fruits (rated on a 6-point Likert-scale: several times a day, once daily, several times per week, once a week, once a month, never, or very rarely). Individuals were also asked whether and how often they shop at stores which sell primarily healthy food (regularly, occasionally, never).
Supplemental orthorexia nervosa-related questions
Ten further questions were added to the ORTO-15 based on the descriptions of reviews and clinical reports about ON [1, 2, 7]. These were related to food consumption habits (so-called health food, timing, food color choices), prejudices and attitudes related to obesity and problems with controlling desires. Individuals had to rate whether they agree or not with the items.
Supplemental orthorexia nervosa-related questions used in this study:
I consume only healthy foods.
I always eat according to my eating schedule.
Sexuality plays an important role in my life.
Being overweight is a sign of weakness.
I avoid food with specific colors.
I disapprove of people who cannot overcome their desires.
I think most people can be blamed for their own diseases.
I always eat the same meals.
I am critical of people who don’t follow the rules of a healthy lifestyle.
I spend a large amount of time preparing my meals.
In order to evaluate the factor structure of the Hungarian version of the ORTO-15, four confirmatory factor analytic models were tested. Model 1 was a three-factor (‘cognitive-rational attributes’, ‘clinical attributes’, and ‘emotional attributes’) model based on the assumptions of the original authors of the instrument . Model 2 was a single-factor model with one factor responsible for all 15 item responses. Since neither of the two models adequately fit the data, a shortened version of the instrument was developed by omitting four items with the lowest item-total correlations and factor loadings. The factor structure of this 11-item version was evaluated by a third confirmatory analytic model using a single-factor solution. Finally, a fourth model was also evaluated containing covariances suggested by modification indices from Model 3.
Internal reliability of the original and the shortened versions was evaluated by calculating Cronbach’s alpha coefficients. Normality of the continuous variables was tested by the Shapiro-Wilk W statistics. Because of the non-normal distribution of our continuous variables, relationships among them were analyzed using nonparametric methods. The Mann–Whitney and the Kruskal-Wallis tests were applied to evaluate the relationships between categorical and continuous variables, while Spearman correlation coefficients were calculated to estimate the strength of the associations between two continuous variables. Confirmatory factor analyses were conducted using AMOS version 20.0, while all other statistical procedures were carried out using SPSS 20.0 software.