Food is the most direct, frequent and abundant substance that the human body contacts with the external environment, and is also the material basis of the internal environment and metabolism of the organism. Diet is extremely important to patients and is closely related to the disease regression. For wasting diseases such as cancer, proper nutrition is even more important. Malnutrition in cancer patients can lead to increased complications of anti-cancer treatment and mortality, as well as decreased response to anti-cancer treatment. Therefore, it is one of the most important measures in anti-cancer treatment to actively provide nutritional support and treatment to improve the nutritional status of patients. I. Dietary principles 1. It is appropriate to give high protein, high calorie and easily digestible diet, such as fish, shrimp, crab, chicken and duck meat, lean pork, animal offal, beef soup, milk, noodles, wontons, rice soup, honey, soybean products, etc., and pay attention to the combination of animal and vegetable proteins to facilitate protein complementation. 2, the diet should be light, the production of food should be mainly boiled, stewed, braised, avoid eating smoked and fried food, and strictly prohibit the consumption of stimulating condiments, such as pepper, mustard, strong wine, etc. Try to meet the patient’s food requirements without violating medical principles, encourage and guide family members to prepare nutritious diet suitable for the patient’s taste, and pay attention to the color and aroma of the dishes and the temperature of the meals to enhance the patient’s appetite. Recommended foods 1.Anti-cancer foods that enhance immune function, such as shiitake mushroom, silver fungus, black fungus, mushroom, soybean, sweet potato, buckwheat, carrot, peanut, cauliflower, onion, wise-nuts, kelp and sea jelly, etc. These foods can improve the vitality of macrophages to engulf cancer cells and are beneficial to anti-cancer. 2.Eat more fresh vegetables and fruits rich in vitamin C, such as rape, spinach, cabbage, tomato, orange, mountain plant, fresh date, monkey peach, lemon, etc. It is experimentally proved that eating more foods rich in vitamin C has cancer prevention and anti-cancer effects. Malignant tumor growth to break through the intercellular matrix, and vitamin C is involved in the structure of the intercellular matrix, its barrier role can protect the structural integrity of the intercellular matrix, vitamin C can also block the production of amine nitrite, thus playing a role in cancer prevention. 3.Eat more foods rich in vitamin A, such as carrots, kudzu leaves, rape, animal liver, cod liver oil and so on. The main function of vitamin A is to maintain the normal structure of epithelial tissues, stimulate the body’s immune system, mobilize the body to fight against cancer and resist the invasion of carcinogens.