Orthorexia nervosa (ON) has been defined as an obsessive and pathological attitude towards healthy nutrition. The aim of this study was to compare individuals who followed a vegan, vegetarian, and omnivore diet in terms of ON behaviors and to examine their prime motivations, attitudes, and behaviors towards food. The Spanish version of the ORTO-15 test - ORTO-11-ES - and the Food Choice Questionnaire (FCQ-SP) were used with a demographic questionnaire in an online survey disseminated among the social networks of different vegetarian associations and the general population. Of 466 individuals, 55% followed an omnivore diet, 23.5% were vegetarian and 21.7% were vegan. Results revealed relationships between type of diet and FCQ-SP dimensions for: health and natural content = 8.7, < 0.05), sensory appeal ( = 11.4, < 0.01), weight control ( = 40.4, < 0.01), and familiarity ( = 37.3, < 0.01). Our results confirm the findings of recent studies showing that individuals who follow a vegan or vegetarian diet are more likely to develop a pathological preoccupation with healthy eating versus omnivores. Further studies are required to determine the potential lines of action for the prevention of ON.