A friend saw me smoking more and more and said with concern: “Quit smoking! My uncle smoked for more than 20 years, and he left years ago.” I was a bit moved and was about to put out my cigarette when I asked him, “What kind of cancer did your uncle have?” He sighed and said, “He was hit by a car on the road”. 1. Reasonable diet: In the daily diet, vegetables, fruits, beans, cereals and other plant foods should account for more than 2/3 of the total amount of food eaten. 2. Weight control: weight should neither be too heavy nor too light, and the weight increase should not exceed 5 kg in adulthood. Body Mass Index (BMI) measurement, BMI = weight (kg) / height squared (height in meters), BMI of 20 to 24 is the ideal weight 3, is to adhere to physical exercise: if there is little daily activity or only light activity, there should be an hour of brisk walking or similar exercise every day, and at least one hour of sweaty strenuous exercise every week (the elderly and infirm should be based on their 4, is to eat more vegetables, fruits: every day should eat 400- 800 grams of fruits and vegetables. Green leafy vegetables, carrots, potatoes and citrus fruits have the strongest effect on cancer prevention. You should eat more than 5 kinds of fruits and vegetables every day and insist on them for a long time in order to have sustainable cancer prevention effect. 5. Pay attention to eating some cereals. Eat 600-800 grams of various cereals, beans and plant roots every day, the less processed food is better, and less refined sugar should be eaten. 6, is not advocate drinking alcohol: even if drinking alcohol, men should not exceed 50 ml a day (non-spiritual wine, red wine is better), women do not exceed 25 ml a day. 7, is not to eat an excessive amount of red meat: eat red meat (Wang to refer to beef, lamb, pork) should not exceed 90 grams a day. It is best to eat fish and poultry instead of red meat. 8, is to eat less high-fat food. Eat less animal fat, choose the appropriate vegetable oil and moderate the amount. 9, is to eat less salt: eat less pickled food, daily salt intake should be controlled within 6 grams. 10, is not to eat food stored at room temperature for too long: because these foods may be contaminated by fungal toxins. 11.It is to preserve perishable food with refrigeration or appropriate methods. 12. is to prevent contamination of food. Food additives, contaminants and residues in the level of less than the national limit is safe, but the indiscriminate or improper use may affect health. 13, is not to eat burnt food. Directly on the fire grilled fish or cured meat bacon can only occasionally eat. Fourteen is not overly dependent on nutritional supplements. For people whose diet basically follows the above recommendations, there is generally no need to consume nutritional supplements, as it may not help much in reducing the risk of cancer.