ABSTRACT This cross-sectional study, conducted on 4003 participants aged between 18 and 45, aims to contribute to orthorexia nervosa (ON) research by examining the relationship between ON, body image and nutritional adequacy. The Orthorexia Nervosa-11 scale (ORTO-11) and body perception scale were applied to individuals, and food consumption records were taken with a 24-hour dietary recall method. The study found that more individuals with orthorexia nervosa (ON) considered themselves overweight compared to non-ON individuals. Evaluating diet quality, the mean adequacy ratio was significantly higher in ON individuals. Nutrient adequacy ratios for total fiber, magnesium, zinc, thiamine, folic acid, and vitamin C were higher, while those for carbohydrate and iron were lower in ON individuals. Additionally, increasing the number of snacks, protein, and total fiber adequacy decreased the ORTO-11 score. Distorted body image perception may be a risk factor for ON, but healthy eating fixation does not lead to nutrient inadequacy unless it involves progressive food restriction.