It is well known the role of diet in the management of overweight and obese type 2 diabetic patients. Even a modest weight loss (5% to 10% of total body weight) is associated with improvements of cardiovascular risk factors. The traditional recommendations regarding the intake of macronutrients are: carbohydrate intake 45% to 65% of total energy, a total fat intake ≤ 35% of total energy (with reduction of saturated and trans fat intake and increase monounsaturated fatty acids intake) and protein intake 15% to 20% of total energy. The recent guidelines recommend increased flexibility in macronutrient composition. In this article I present different dietary patterns (such as low carbohydrate diets, high protein diets, low calorie diets, very low calorie diets and Mediterranean diet) used in the management of type 2 diabetic patients, their effects on short-term outcomes as well as on long-term outcomes. Energy restriction is required for weight loss. In short-term trials high-protein, low-carbohydrate diets are more favorable for weight loss than traditional high-carbohydrate, low-fat diets. Very important in weight loss and metabolic control are the adherence to a diet and pharmacotherapy. Recently probiotic and prebiotic have been proposed as a new treatment strategy.