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, R2 = 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, R2 = 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.
Bryl et al. (Tue,) studied this question.