Background <p>Appropriate management of health and nutritional status is essential for athletes to maintain performance, enhance recovery, and prevent injuries. Nutrition education aims to improve health and nutritional status through changes in dietary behaviors, thereby supporting athletic sustainability and quality of life. Previous systematic reviews have primarily focused on intermediate outcomes such as nutrition knowledge and behaviors, whereas health and nutritional status as final outcomes and the effectiveness of nutrition education interventions have not been systematically organized. This review aimed to (1) summarize health and nutritional status outcome measures used in nutrition education intervention studies targeting athletes and (2) examine the effectiveness of these interventions in relation to outcome consistency and alignment with intervention objectives.</p> Methods <p>This systematic review was conducted in accordance with PRISMA guidelines and registered in PROSPERO (CRD42023417419). Seven databases were searched for studies published between April 2003 and March 2025. Eligible studies included randomized controlled trials, non-randomized controlled trials, and pre–post intervention studies involving athletes aged ≥ 12 years. Nutrition education interventions included lectures, counseling, and face-to-face or online programs delivered to individuals and/or groups. Outcomes included objective and/or subjective indicators of health and nutritional status.</p> Results <p>Twenty-four studies involving 845 athletes were included. All studies assessed anthropometric or body composition measures such as body weight, fat mass, and fat-free mass. Biochemical indicators were less frequently used, with hydration status assessed by urine specific gravity in three studies and blood biomarkers in three studies. Subjective health-related outcomes were rarely evaluated. Intermediate outcomes such as nutrition knowledge and dietary behaviors were assessed in 12 studies. Studies in which intervention objectives, educational content, and outcome measures were aligned tended to report improvements corresponding to their stated objectives.</p> Conclusions <p>In nutrition education intervention studies targeting athletes, objective measures of body weight and body composition are commonly used, whereas subjective health status assessments remain limited. Nutrition education may be effective for intermediate outcomes such as nutrition knowledge and dietary behaviors, but evidence for effectiveness in physiological and biochemical outcomes remains inconclusive. Aligning intervention objectives, educational content, and evaluation measures within a nutrition management framework may be important for appropriately evaluating effectiveness. Repeated nutrition education interventions may contribute to sustainable behavioral and health-related changes in athletes.</p>