From Nutrition Knowledge to Health-Related Behaviors in Undergraduate Nursing Education: A Cross-Sectional Study

Background/Objectives: Nutrition knowledge is an important component of undergraduate nursing education, but greater knowledge does not necessarily translate into healthier personal behaviors. This study aimed to assess nutrition knowledge and health-related behaviors among undergraduate nursing students, compare these outcomes across academic years, and identify factors associated with both dimensions. Methods: A cross-sectional study was conducted among students enrolled in the four-year nursing degree at the University of Santiago de Compostela, Spain, during the 2025/2026 academic year. Participants completed a study-specific ad hoc questionnaire assessing sociodemographic characteristics, nutrition knowledge, dietary and health-related behaviors, self-rated dietary quality, and body mass index (BMI) perception. Bivariate analyses, multiple linear regression, ordinal logistic regression, and weighted Cohen’s kappa were used. Results: A total of 297 students participated (50.9% response rate); 81.1% were women. Mean nutrition knowledge was 22.51 ± 4.01/36 and differed across academic years, ranging from 21.56 ± 3.74 among first-year students to 24.64 ± 3.87 among fourth-year students (p < 0.001). The mean health-related behaviors score was 76.26 ± 7.01/105 and did not differ across academic years (p = 0.103). Behavior score increased from 68.33 ± 7.78 among students rating their diet as poor to 84.81 ± 4.32 among those rating it as very good (p < 0.001); each 10-point increase was associated with higher odds of reporting a better dietary-quality category (adjusted OR = 7.78; 95% CI: 4.99–12.13). Exact agreement between calculated and self-perceived BMI categories was 82.7% (weighted κ = 0.593). Conclusions: Nutrition knowledge was higher among students in later academic years, whereas health-related behaviors did not show a similar academic pattern. These findings suggest that undergraduate nursing education should reinforce practical and behavior-oriented nutrition learning alongside theoretical knowledge.