Prevalence and characteristics of orthorexia nervosa in a sample of university students in Italy

Aims: Orthorexia nervosa (ON) has been recently defined as a pathological approach to feeding related to healthiness concerns and purity of food and/or feeding habits. This condition recently showed an increasing prevalence particularly among young adults. In order to investigate the prevalence of ON and its relationship with gender and nutritional style among young adults, we explored a sample of students from the University of Pisa, Italy. Methods: Assessments included the ORTO-15 questionnaire and a socio-demographic and eating habits form. Subjects were dichotomized for eating habits (i.e. standard vs vegetarian/vegan diet), gender, parents’ educational level, type of high school attended, BMI (low vs high vs normal BMI). Chi square tests were performed to compare rates of subjects with overthreshold ORTO-15 scores, and Student’s unpaired t test to compare mean scores between groups. Two Classification tree analyses with CHAID growing method were employed to identify the variables best predicting ON and ORTO-15 total score. Results: more than one-third of the sample showed ON symptoms (ORTO-15 ≥ 35), with higher rates among females. Tree analyses showed diet type to predict ON and ORTO-15 total score more than gender. Conclusions: Our results seem to corroborate recent data highlighting similarities between ON and anorexia nervosa (AN). We propose an interpretation of ON as a phenotype of AN in the broader context of Feeding and eating disorders (FEDs) spectrum.