Nutritional considerations for athletes with diabetes: optimizing performance and glycemic control

Athletes with diabetes encounter the intricate physiological challenge of harmonizing optimal physical performance with meticulous glycemic control. Although nutritional management is crucial for success, generic guidelines often do not provide the required differentiation for various diabetes causes and contemporary insulin delivery methods. This narrative review aims to consolidate the latest research on optimizing macronutrient intake, hydration, and micronutrient support specifically for athletes with Type 1 (T1D) and Type 2 (T2D) diabetes. A structured search of the literature was conducted on Google Scholar (2015–2025) to identify relevant peer-reviewed clinical trials, meta-analyses, and expert consensus statements. The identified nutritional strategies were then analyzed and classified based on an evidence-grading framework: Level A (Strong evidence/Meta-analyses), Level B (Moderate evidence/Single RCTs), and Level C (Expert consensus). Carbohydrate timing and dosing are crucial factors in maintaining normal blood sugar levels during exercise, and they need to be adjusted based on the intensity and duration of the activity, as well as the type of insulin therapy being used (e.g., multiple daily injections vs. automated insulin delivery systems). This review presents structured guidelines for managing carbohydrate intake before, during, and after exercise, highlighting the importance of protein for muscle recovery and the influence of micronutrients like magnesium and vitamin D on metabolic function. Additionally, the use of Continuous Glucose Monitoring (CGM) data is discussed as a valuable tool for reducing fluctuations in blood sugar levels and preventing exercise-induced hypoglycemia. Optimizing athletic performance in individuals with diabetes necessitates a comprehensive, multidisciplinary strategy. By coordinating dietary choices with appropriate treatment modalities and utilizing evidence-based assessments, healthcare providers can offer more secure and efficient recommendations for both competitive and recreational athletes.