Nutritional knowledge as a protective factor against eating disorders and a risk factor for orthorexic tendencies.

This cross-sectional study examined the relationships among nutritional knowledge, eating disorder symptoms, orthorexia-related scores, and body satisfaction among Turkish adults. A total of 1,457 adults aged 19-64 years completed an online questionnaire including the Nutrition Knowledge Scale, Eating Attitudes Test-40, ORTO-11 Orthorexia Scale, and Body Satisfaction Scale. Descriptive statistics, Pearson correlation analyses, and hierarchical multiple regression analyses were conducted. The mean Nutrition Knowledge Scale score was 81.42 ± 17.61, and 46.3% of participants were classified as having low nutritional knowledge. After adjustment for demographic, health, and lifestyle covariates, higher nutritional knowledge was significantly associated with lower Eating Attitudes Test-40 scores (β = -0.151, p < 0.001), higher ORTO-11 scores (β = 0.126, p < 0.001), and higher Body Satisfaction Scale scores (β = 0.133, p < 0.001). These findings suggest that nutritional knowledge may be linked to fewer disordered eating symptoms and greater body satisfaction. However, interpretation of the ORTO-11 findings requires caution because lower ORTO-11 scores indicate greater orthorexia risk in the original scoring direction. Nutrition education programs should therefore promote accurate knowledge while also supporting flexible eating attitudes, positive body image, and psychological well-being. Future longitudinal studies using updated orthorexia assessment tools are needed to clarify causal pathways and the role of cultural and psychosocial mediators.