This study aimed to translate, culturally adapt, and validate "The Nutrition for Sport Knowledge Questionnaire (NSKQ)" for Brazilian athletes. The NSKQ is an Australian instrument composed of 87 questions divided into six subsections (weight control, macronutrients, micronutrients, sports nutrition, supplementation, and alcohol) designed to assess the nutritional knowledge (NK) of athletes. The translation process followed the recommendations of the World Health Organization for translating and adapting instruments. Semantic validation involved a panel of specialists (n = 21), followed by an assessment performed by a group of adult Brazilian athletes from various sports (n = 17). The reproducibility and internal consistency of the questionnaire were evaluated via a test-retest approach in a sample of adult Brazilian athletes (n = 29) from diverse sports, who completed the Brazilian version of the NSKQ (NSKQ-BR). Overall, the NSKQ-BR presented good internal consistency (α = 0.95) and reproducibility (intraclass correlation coefficient (ICC) = 0.85). The factors "sports nutrition" and "alcohol" showed moderate reproducibility (ICC = 0.74 (0.46-0.88) and ICC = 0.68 (0.33-0.85), respectively). Most athletes (n = 17; 58.6%) presented a medium NK score (50-65%). The NSKQ-BR is available to evaluate the NK levels of Brazilian athletes. The NSKQ-BR presented high internal consistency and reproducibility, validating its applicability among adult athletes across diverse sports.
Keywords: Brazilian; Portuguese; nutritional knowledge; sports; surveys and questionnaires; translation and validation.