The three major nutrients in a diabetic diet refer to carbohydrates, proteins and fats. Diabetic patients should limit the total daily calories and pay attention to the ratio of the three major nutrients. Carbohydrates should supply 50%-60% of the total calories, including various grains and tuber vegetables, such as potatoes, yams, and various kinds of mixed beans, etc. Food selection should try to choose grains with low glycemic index and avoid various snacks and sugary drinks. Protein food supplies 15%-20% of the total calories, including various kinds of meat, milk, eggs and soybean products, to consume more meat, milk, eggs and other high-quality protein, especially diabetic nephropathy patients should avoid the intake of vegetable protein. Fatty foods supply 25%-30% of the total calories, mainly from vegetable fats and various nuts, and animal fats should be consumed sparingly.