Nutritional Knowledge, Sociodemographic, and Lifestyle Factors as Determinants of Diet Qualitya Polish Population-Based Study

Alicja Kucharska^1,2*Beata Irena Sińska²Mariusz Panczyk³Piotr Samel-Kowalik⁴Filip Raciborski⁴Aneta Czerwonogrodzka-Senczyna⁵Iwona Boniecka⁶Iwona Traczyk⁵

• ¹Medical University of Warsaw, Warsaw, Poland
• ²Department of Human Nutrition, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Masovian, Poland
• ³Department of Education and Research in Health Sciences, Medical University of Warsaw, Warsaw, Poland
• ⁴Department of Prevention of Environmental Hazard and Allergology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Masovian, Poland
• ⁵Department of Dietetics, Faculty of Health Sciences, Wroclaw Medical University, Wrocław, Silesian, Poland
• ⁶Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Capital Region of Denmark, Denmark

Introduction: Nutritional knowledge is a recognized determinant of dietary behaviors, though its impact may vary with sociodemographic and lifestyle factors. To capture such interactions and population variability, advanced methods like moderation and latent class analyses are needed. This study aimed to examine the relationship between nutritional knowledge and diet quality among Polish adults, accounting for socioeconomic determinants, and to identify subgroups at risk of poorer dietary patterns.A cross-sectional study was conducted using data from two nationally representative surveys (2017-2020), totaling 4000 adults. Nutritional knowledge was measured with the validated KomPAN questionnaire, and diet quality was assessed with the Diet Quality Index (DQI). Associations were tested via linear regression, moderation analysis explored interactions between knowledge and demographics, and latent class analysis (LCA) identified dietary lifestyle subgroups.The mean DQI score was -0.79 (SD = 13.40). Higher nutritional knowledge (β = 0.87, p < 0.001) and higher education were positively associated with diet quality. Women and older adults had better diets; smoking and alcohol consumption were linked to poorer outcomes. Multivariate models confirmed nutritional knowledge, sex, and age as independent predictors. The beneficial effect of knowledge was weaker in older adults (β = -0.49, p < 0.001). LCA revealed three profiles; the poorest diets occurred among younger men with low knowledge and unhealthy behaviors, and younger adults with higher socioeconomic status. Conclusion: Nutritional knowledge supports better diet quality but may not suffice especially in older adults. Tailored public health strategies are needed for vulnerable groups, including younger men with low knowledge and those with higher socioeconomic status but poor diets.