Interplay between sports nutrition knowledge, lifestyle factors, and body mass index among regularly exercising...

This study aims to comprehensively examine the complex relationships among sports nutrition knowledge, nutritional status (macro- and micronutrient intake), body mass index (BMI), and lifestyle factors (smoking status, dietary habits including salt preference, daily water consumption, dietary supplement use, and exercise characteristics) in university students who engage in regular exercise.

This cross-sectional analytical study was conducted between December 2023 and April 2024 with 454 university students (172 males, 282 females) enrolled in universities in İzmir, Türkiye, who self-reported engaging in regular exercise. Data were collected using the Abridged Nutrition for Sports Knowledge Questionnaire (A-NSKQ), two non-consecutive 24-hour dietary recalls (one weekday and one weekend day) analysed with BeBiS^® v9.0, and sociodemographic/lifestyle questionnaires. Hierarchical multiple linear regression analysis was employed to identify factors predicting BMI and weekly regular exercise duration. Mann-Whitney U, Kruskal-Wallis, and Spearman correlation tests were used for statistical analyses (p < 0.05).

Most participants (75.1%) demonstrated inadequate sports nutrition knowledge on the A-NSKQ, with this proportion being higher among females (81.2%) than males (65.1%). Male students had significantly higher weekly total regular exercise duration (p < 0.001), A-NSKQ scores (p < 0.001), and BMI (p < 0.001) compared with females. A-NSKQ level was not associated with macronutrient intake (carbohydrates, protein, fat) (p > 0.05); however, higher A-NSKQ was significantly associated with better intake of certain micronutrients, including vitamin E (p = 0.005), riboflavin (p = 0.021), iron (p = 0.033), and zinc (p = 0.034). Gender (β = -0.436), daily energy intake (β = -0.091), smoking status (β = -0.163), and daily water intake (β = 0.159) were identified as significant predictors of BMI (all p ≤ 0.001), with protein intake (%E; β = 0.091, p = 0.030) showing a weaker positive association, while A-NSKQ score and weekly regular exercise duration were not. The final regression model was significant and accounted for a meaningful proportion of the variance in BMI (R² = 0.245; Adjusted R² = 0.231).

Despite being physically active, university students exhibit notably low levels of sports nutrition knowledge, particularly among female students. Although knowledge level does not predict BMI or macronutrient intake, it shows a positive association with the intake of key micronutrients. The current situation highlights the disconnect between theoretical knowledge and its application in practice; in other words, a clear knowledge-behaviour gap. The findings confirm that active university students who engage in regular exercise require not merely theoretical, but directly practical and goal-specific nutrition education to achieve their health and performance objectives.