Being a nutrition student is an important risk factor for developing orthorexia nervosa according to different international studies (9, 16–19). Considering the rise in enrollment rates and increase in the number of students in Chile, it is necessary to develop incentives which allow for identifying associated factors which promote the condition and allow us to establish lines of action for prevention and management. In this line, the present study constitutes an important precedent as the first work of this nature at the national level, and along with two studies done in Brazil in previous years, the only work undertaken in South America.
The principal results include the evidence of an ON risk prevalence rate of 23.3%, greater than described for the general population or the rate described by Escobar et al., (2019) among Peruvian medical students (15). Other rates were reported at between 30–80% among nutrition students, however, all studies used different versions of the ORTHO instrument, making comparisons unviable. A publication by Dunn et al. declared that these values were overestimated, apart from indistinct use of the terminology related with diagnosis and risk, demonstrating the need for greater caution when comparing these results. It would be interesting to analyze which out of all the ORTHO versions generated has a better diagnostic capacity, especially because of the ORTHO-15 results which report rates above 50% of evaluated samples. It is also important to mention that these evaluations mainly focused on European populations, where sociodemographic and sanitary realities are very different from the reality of Chilean university students (20–22).
One major goal of the present study was to identify factors associated to ON risk in nutrition students. Curiously, being in the second year is more associated with ON risk than other levels. Even as the major progresses, and nutritional knowledge therefore expands, the risk diminishes. The present result could be mediated by the courses done during the second year of the major, which involves a sudden inclusion of disciplinary courses associated with self-measurement of body segments, including Nutritional Status Evaluation, along with quantitative food evaluation in areas including Basic Nutrition and Food Planning (23, 24). The drop in ON prevalence by level as the years advance (Table 5) could be due to the orientation of the following courses, which focus more on the qualitative value of food and healthy criteria about body composition, contributing a non-reductionist training regarding the characterization of food and ideal body composition. It would be interesting to compare this with other studies; however, there is no risk characterization by level in the studies done to date, making our results unprecedented in this sense.
Regarding the other associated factors, in prior studies secondary educational establishment type was identified as a variable associated with ON risk. During 2015, Jerez et al. (7), evaluated a cohort of secondary school students who came from different schools, reporting higher rates in public state schools. This reoccurred in our study, where students from private schools had only a 15% risk of ON, which was lower than charter school students at 28% (OR 3.00). Considering this, along with Chilean inequality levels, it would be interesting to evaluate in future studies whether food and nutrition education is a protective factor against ON in adolescence and/or adulthood, as has been reported with other educational interventions against Anorexia and Bulimia (25, 26). It could also be possible that, depending on socioeconomic level, home diet quality will show concrete differences with knowledge acquired in higher education, placing individuals in undesired vulnerable conditions which are hard to remedy (27).
Another factor associated with ON risk observed in this sample is limited cohabitation with one person or less, which places perceived social support as a variable to consider, as reported by various publications discussing eating disorders more generally (28). However, when queried about extracurricular activities, a lack of engagement with them did not constitute a risk factor associated with ON. This could be influenced by the variability of activities performed, with an understanding that not all are associated with increasing social support, including practicing individual sports and exercise (29). Simultaneously, the current strict social distancing measures in Chile could be a limiting factor for positive aspects of extracurricular activities considering how in-person activities have transformed into remote events (30). Furthermore, nutritional status in this student sample was not an element for consideration, which could be related to specific social pressure in this population group, with their general preoccupation for body composition and nutritional status, regardless of what their classification may be.
The results for the physical activity and Instagram use variables are interesting, since limiting categories throw out association with ON risk. This situation presents the fact that both sedentary status and heavy physical activity are factors on which to focus. The same thing happens with social network use, where spending less than 1 hour per day and spending 3 or more hours per day were both factors associated with ON risk in this sample. This provides evidence for avoidance as a coping strategy for this problem among sedentary subjects who present limited interaction with social media; the latter point is unprecedented in comparison with international evidence (14). On the other extreme, subjects who undertook excessive physical activity and overused Instagram could be influence by beauty standards created in gyms and social networks, including “Fitspiration” dynamics (31).
It should be mentioned that there are important limitations on this study considering the number of subjects evaluated. However, the sample is a representative number for the quantity of people enrolled in an average university Nutrition and Dietetics major in Chile. This is why the present pilot initiative presents several interesting variables worth investigating which had not been identified in other studies, such as major year and duality in social media use. However, considering the nature of the study, interpretation should be taken with caution considering the design used.
Future studies should try to have more representativeness, expanding the sample size and considering schools from different regions around the country in order to reproduce the geographical and populational heterogeneity of Chile. Furthermore, a longitudinal design contrasted with a control population would allow us to evaluate the risk or protective factor condition of the variables which were studied, vis-à-vis ON risk in this specific population.