Effect of a nutrition education intervention on sports nutrition knowledge, dietary intake, and body composition in female athletes: a randomized controlled trial

Background/objectives: Adolescent female athletes often present insufficient dietary intake and limited sports nutrition knowledge (SNK). This study aimed to evaluate the effects of a short-term nutrition education intervention on SNK, dietary intake, and body composition in adolescent female handball players. Methods: A community-based randomized controlled trial was conducted. Four handball clubs were randomly assigned to either an intervention group (IG) or a control group (CG). The IG received a nutrition education program consisting of three 30-min face-to-face group sessions delivered by a registered dietitian. The CG did not receive any nutrition education intervention during the study period. SNK, dietary intake, Mediterranean diet adherence (MD), and anthropometric and body composition measurements were assessed at baseline and follow-up in both groups. Results: < 0.05, effect size > 0.8). Baseline dietary records revealed, in both groups, insufficient energy intake (30 kcal/kg/day) and carbohydrate intake (2.7 g/kg/day), alongside a high total fat intake (1.5 g/kg/day). At baseline, 77.8% of the IG and 78.0% of the CG required improvements in adherence to the MD. No significant changes were observed in dietary intake, MD adherence, or body composition in either the IG or CG following the intervention. Conclusion: A brief nutrition education intervention effectively improved SNK in adolescent female athletes. However, these improvements did not translate into changes in dietary intake or body composition. These findings suggest that interventions incorporating behavioral strategies may be necessary to achieve significant dietary changes in this population. Clinical trial registration: ClinicalTrials.gov, identifier (NCT07460102).