BackgroundOrthorexia and muscle dysmorphia are disorders affecting above all young adults whose prevalence and social impact are still unclear. We aimed to evaluate the prevalence of the traits of orthorexia and muscle dysmorphia among freshmen attending university courses focused on nutrition (Dietetics) and body care (Exercise and Sport Sciences). Students of Biology were considered as a control group. The prevalence of eating disorder (ED) traits were also evaluated.MethodsAll participants (n = 440; n = 53 Dietetics school, n = 200 Exercise and Sport Sciences school, n = 187 the Biology school) completed the following questionnaires: ORTO-15, Muscle-Dysmorphic-Disorder-Inventory, and Eating Attitudes Test-26.ResultsThe prevalence of the traits of EDs, orthorexia, and muscle dysmorphia was 9.1%, 25.9%, and 5.9%, respectively. When compared to other students, those attending the Dietetics school showed a 2-fold higher risk of EDs and those from the Exercise and Sport Sciences school a 10-fold higher risk of muscle dysmorphia. The prevalence of orthorexia traits was high in all schools (35.9%, 22.5%, 26.5% in Dietetics, Biology, and Exercise and Sport Sciences schools, respectively). Overall, individuals with traits of any of these disorders were more frequently on diet or on supplement use. In a logistic regression model, attending the Dietetics school (OR = 2.71; 95% CI 1.14-6.48) was significantly associated with the ED traits, but not with the orthorexia traits (OR = 1.75; 95% CI 0.93-3.29), while attending the Exercise and Sport Sciences school was significantly associated with the muscle dysmorphia traits (OR = 5.15; 95% CI 1.44-18.4). Finally, when evaluating the relationships among the types of study programs as dependent variables and traits of these disturbances, the associations between the traits of ED (OR = 3.35; 95% CI 1.38-8.13) and matriculation at the school of Dietetics, and between the traits of muscle dysmorphia (OR = 4.32; 95% CI 1.16-16.1) and the choice of the Exercise and Sport Sciences school were confirmed.ConclusionsThe choice of the university courses might be influenced by pre-existing disorders in eating behaviors, which were relatively frequent in the considered sample.