Tumor is a lifestyle-related disease. One third of tumors are related to daily diet and nutrition, and digestive tract tumors are more closely related to diet. Through proper nutrition and adjusting dietary habits can prevent 30-40% of tumors. Various kinds of meat can be divided into red meat and white meat according to the color of their raw meat. In daily life, it can be simply classified roughly as follows: four-legged animals such as pigs, horses, cows and sheep are red meat, two-legged animals such as chickens, ducks, geese and birds are red and white, and animals without legs such as fish are white meat. In fact, all animals contain red meat and white meat, only the amount of content is different. Meat products such as sausages, cured meats, hams, bacon, and luncheon meats are collectively referred to as processed meats. Studies have found that red meat can increase the incidence of many tumors, while white meat has no such effect. Processed meat has similar effects to red meat and also increases the incidence of many types of tumors. From the perspective of tumor prevention, four-legged is better than two-legged, two-legged is better than no-legged, domesticated is better than wild, captive is better than free-range, land is better than water, river is better than sea, and processed is better than fresh. In real life, is it possible for us not to eat red meat or processed meat? No way! On the one hand, meat is a human hobby and a source of high-quality protein; on the other hand, red meat is rich in iron, rich in protein, zinc, niacin, vitamin B12, thiamine, riboflavin and phosphorus, which are all essential nutrients for the human body. So, how do we prevent or avoid the adverse consequences of red meat and processed meat? First, we should reduce the intake of red meat and processed meat, and control it within 5 times a week; second, we should increase the intake of antioxidant foods (such as fresh vegetables, fruits, green tea); third, we should increase the proportion of non-processed meat such as fresh meat and white meat such as chicken, duck, goose, fish, etc. in the total meat intake. A balanced diet is the most important, vegetarian and non-vegetarian food should be well matched, too much partial food such as excessive meat fasting is undesirable, because it is more likely to lead to a decrease in body resistance and thus tumor occurrence or recurrence. We must remember that for malignant tumors, the “three early” strategies of early detection, early diagnosis and early treatment are the best strategies to prevent and control cancer.