Nowadays, social media and rapidly changing dietary trends encourage people to constantly-often excessively-control their diet, which leads to an increased risk of developing eating disorders, including orthorexia nervosa (ON). At the same time, more and more people reduce or give up consumption of meat and other animal products, adopting different types of plant-based (vegetarian) diets. The following paper aimed to demonstrate the significant similarities between orthorexia and plant-based diets and to highlight the necessity of developing new or adapting existing diagnostic tools for orthorexia considering the lifestyle characteristics of vegetarians, especially vegans. It remains unclear whether vegetarianism increases the risk of developing ON or whether the development of ON increases the chances of switching to a plant-based diet. However, based on the available literature, a positive association can be shown between the two. On the one hand, a vegetarian diet may be a cover for ON, but on the other, vegetarians, as a group avoiding specific food products, may be wrongly perceived as disordered. Thus, it is important to distinguish ON from the so-called healthy orthorexia (HO), which is a non-pathological interest in healthy eating, to avoid overdiagnosis and stigmatization of people using healthy alternative diets, including plant-based diets, since the mere fact of following them does not constitute evidence of orthorexia.
Keywords: eating disorders; healthy orthorexia; orthorexia nervosa; plant-based diets; vegan; vegetarian.