Abstract
BACKGROUND/OBJECTIVES: Proper nutrition is crucial for the growth, development, and performance of young football players. Despite higher nutritional needs, physically active adolescents often have a suboptimal diet. This study assessed the diet quality of youth football players aged 11-16 from Poznań, Poland, focusing on the frequency of consuming health-promoting and non-healthy food groups. METHODS: Participants were Football Championship School students. A total of 78 boys were analyzed and divided into early (11-13 years) and middle adolescence (14-16 years) groups. Dietary behaviours, nutritional knowledge, physical activity, screen time, and family affluence were assessed using a validated questionnaire (SF-FFQ4PolishChildren). The pro-Healthy Diet Index (pHDI) and non-Healthy Diet Index (nHDI) were calculated based on the frequency of food consumption. RESULTS: The key predictors of the pro-Healthy Diet Index (pHDI) were the Cole index (β = -0.39; p < 0.001), subjective self-assessment of dietary habits (β = 0.23; p = 0.023), and the level of nutritional knowledge (β = 0.22; p = 0.030), explaining 25% of the variance in pHDI. In early adolescence, the Cole index was the main predictor (β = -0.51, p < 0.001, R(2) = 32%), whereas in middle adolescence, self-assessment of dietary habits (β = 0.49, p = 0.002) and nutritional knowledge (β = 0.34, p = 0.03, R(2) = 30) were the strongest predictors. Despite high levels of physical activity and positive self-assessment, only 1.28% of participants met all key criteria for a healthy diet. Screen time was negatively correlated with physical activity and positively associated with energy drink consumption. CONCLUSIONS: The results highlight a discrepancy between declared knowledge and actual behaviours, emphasizing the need for targeted, multi-level interventions involving families and coaches to improve dietary practices in young athletes.