Currently, there are about 50 million diabetic patients worldwide. By 2030, the number of diabetics will grow due to population growth and longer life expectancy. Diabetes, in the middle-aged and elderly population, is a common disease. In particular, people who are fat, or have a family history of diabetes, are more likely to get this disease. It is a group of syndromes caused by chronic hyperglycemic state, the cause of complex and diverse, has not been fully elucidated. However, diabetes is closely related to obesity, reduced physical activity, dietary habits, and genetic and environmental factors. Diabetes mellitus can be divided into two categories: primary diabetes mellitus and secondary diabetes mellitus. The clinical manifestations of diabetes mellitus are generally thirst, excessive drinking, excessive urination, excessive eating and weight loss, commonly known as the “three more and one less” symptoms. The metabolism of the body is disturbed, and complications such as ketoacidosis, progressive nephropathy, retinal microangiopathy, atherosclerosis and cataracts may occur. There is no cure for diabetes, but a combination of diet control, medication and physical activity can be used to bring the patient to a “healthy condition”. Diet control is the basic treatment for diabetes. Diabetic patients must control the diet, especially some light diabetic patients, such as proper dietary control, the disease can be significantly improved, and some can be basically cured. Even some elderly heavy diabetic patients, control diet can also reduce the symptoms, and can improve the efficacy of hypoglycemic drugs, thereby reducing the amount of drugs. Patients had better calculate their daily calorie requirements according to their age, gender, height standard weight, so that the total calorie intake can be adjusted appropriately according to the activities. It is usually calculated at 32-36 kcal per kg of body weight and can be reduced at the discretion of obese people. Then arrange the amount of protein, fat and sugar to be consumed respectively. The total amount of protein required per day should be calculated at 1-1.5 grams per kilogram of body weight, and the amount generated by protein should be subtracted from the total calories, and the remaining calories should be supplemented by sugar and fat. The ratio of sugar to fat is 2.5:1; sugar should account for 50-65% of the total calories, and the amount of calories produced by fat should not exceed 40% of the total calories, and vegetable oils rich in unsaturated fatty acids should be used as much as possible. The distribution of staple foods in breakfast, lunch and dinner is 1/5, 2/5 and 2/5. All kinds of foods that are likely to cause a rapid rise in blood sugar in diabetic patients should be included in the scope of contraindication. In general, pure sugar and a variety of fruit sugar, cakes and other sugar-rich foods should be prohibited. Staple foods should also be strictly limited, and it is appropriate to eat less refined rice and white flour, eat more coarse grains and a variety of vegetables and other multi-fiber foods. Protein supply should be sufficient. Because of the metabolic disorders of diabetic patients, protein decomposition too fast, the loss of more, so should be supplemented with appropriate amounts of milk, eggs, lean meat, soy products and other protein-rich food. But the amount of food can not be too much, because too much protein can be turned into sugar and fat in the body, and even induce ketoacidosis. The amount of fat intake should be determined according to the patient’s specific situation, and the general patient’s daily intake is 50-60 grams. Patients with lean body can increase fat intake appropriately because of insufficient calorie source after restricting sugar. Fat intake for obese patients should not exceed 40 grams per day. To prevent arteriosclerosis, it is better to consume soybean oil, peanut oil, canola oil, corn oil, etc. Also limit high cholesterol foods, limit cholesterol to less than 300mg per day, and try to eat less brain marrow, fish roe, squid, egg yolk, fatty meat, animal offal, etc. You should also eat less fried food, because food fried at high temperatures often destroy unsaturated fatty acids and vitamins. Moderate physical activity and physical work can also bring down high blood sugar. Patients can choose the appropriate amount of physical therapy load according to the situation. Excessive amount of exercise, sometimes make blood sugar rise. In addition, diabetic patients should avoid overwork, tension, excitement, anxiety, etc., otherwise the condition will be aggravated.