A growing body of evidence shows that lifestyle interventions are critical components of the comprehensive treatment and management of type 2 diabetes, helping in glycemic control, minimizing complications, and slowing the progression of the disease. Furthermore, diet and physical activity can be critical in reducing the risk of developing type 2 diabetes in those at increased risk. Because type 2 diabetes increases the risk of cardiovascular diseases (CVDs) and other conditions, diets for persons with type 2 diabetes usually include recommendations that are appropriate in risk reductions for these comorbidities. This entry provides an overview of the role of diet and nutrients in the prevention and treatment of type 2 diabetes mellitus.