BACKGROUND: Sports nutrition plays a crucial role in providing the fuel to meet the energy demands of athletes' training programmes, enhancing adaptations associated with training, and ensuring rapid recovery between workouts. However, evidence suggests that the dietary habits of many athletes are unsatisfactory when compared to sport-specific nutrition recommendations. This discrepancy is mainly due to a lack of up-to-date, evidence-based nutritional knowledge. Hence, this parallel-group, randomized controlled clinical trial aims to evaluate the effectiveness of a 16-week evidence-based, culturally appropriate, personalized sports nutrition intervention on the sports nutrition knowledge and nutritional status of track and field athletes in Sri Lanka, in comparison to a control group that does not receive this intervention. METHODS: Elite and highly trained track and field athletes, competing at the national level and/or representing Sri Lanka in international competitions, will be randomly allocated to either the intervention group (IG) (n = 15) or the control group (CG) (n = 15). Participants in the IG will receive an evidence-based, culturally acceptable, personalized sports nutrition intervention from the principal investigator through one-to-one consultations at three-time points (zeroth, fourth, and eighth weeks), while participants in the CG will be followed up throughout the period without receiving the intervention. The primary outcome measure is the number of participants who achieve at least a 10% increase in mean sports nutrition knowledge (SNK) score at the end of the 16 DISCUSSION: While the primary objective is to enhance SNK, it is anticipated that improvements in nutritional status and overall health may significantly impact sports performance and career longevity of the athletes. TRIAL REGISTRATION: Sri Lanka Clinical Trials Registry, SLCTR/2024/013. Registered on 10