Early dietary treatment of diabetes mellitus includes controlling total calorie intake, nutrient distribution, and reasonable meal distribution. 1. Control of total calorie intake: those whose weight is lower than ideal weight need to increase calorie intake, while those who are obese need to restrict calorie intake; patients need to formulate the total calorie intake according to their height, age, weight, and labor intensity. 2. Nutrient distribution: the ratio of carbohydrate energy supply in the diet should account for 50%~60% of the total calories, fat accounts for 25%~30%, and protein should account for 15%~20% in diabetic patients with normal renal function. 3. Reasonable allocation of meals: after determining the total calories and the proportion of sugar, protein and fat composition of the daily diet, the three meals per day can be allocated according to 1/3 of each or 1/5, 2/5 and 2/5. 4. Other: should not eat fried food and all kinds of sweets, quit smoking and limit alcohol. Patients diagnosed with early diabetes should actively cooperate with doctors to maintain a healthy diet.