Effective glycemic control is essential in the management of type 2 diabetes mellitus (T2DM) to reduce the risk of complications. Dietary patterns significantly influence blood glucose regulation and metabolic health in these patients. This review synthesizes current evidence on the impact of various dietary approaches?including ketogenic, lowcarbohydrate, Mediterranean, vegetarian/vegan, and low glycemic index diets?on glycemic markers such as HbA1c and fasting glucose. Findings from randomized controlled trials and meta-analyses indicate that ketogenic and low-carbohydrate diets produce substantial reductions in HbA1c, while Mediterranean and low glycemic index diets improve both HbA1c and fasting glucose levels. Traditional diets rich in whole grains and legumes also correlate with better glycemic outcomes, whereas high consumption of sweets and processed meats is associated with poorer glycemic control. Mechanistically, these dietary patterns modulate insulin sensitivity, reduce postprandial glucose excursions, and exert anti-inflammatory effects. Personalized dietary counseling emphasizing nutrient-dense, low glycemic foods is recommended to optimize glycemic control and reduce cardiometabolic risk in T2DM patients. Further longterm studies are warranted to establish sustained efficacy and safety of these dietary interventions.
