The dietary guiding principles for malignant tumor patients are as follows: 1. Reasonable diet and appropriate exercise: reasonable diet refers to maintaining the normal nutrition supply of the body to ensure the needs of growth and development and activities; appropriate exercise refers to having more than 3 times a week and maintaining more than 30 minutes of moderate intensity exercise each time; 2. Maintain appropriate and stable body weight: obesity not only increases the incidence of cardiovascular and cerebrovascular diseases, but also increases the incidence of tumors, such as 3. Diversify food choices to avoid single; 4. Consume more protein-rich foods, such as fish, poultry and eggs, and reduce the intake of red meat, such as common sausages, cured meat and ham, which belong to the category of red meat and increase the incidence of tumors; in addition, avoid smoking, drinking alcohol, moldy, barbecued and pickled foods and fried animal foods; 5. The recommended daily intake of vegetables is 300-500g and fruit is 200-300g; 6. If the dietary intake is not enough during the anti-tumor treatment and rehabilitation treatment, guidance should be given, and if the amount needed is still not met after guidance, enteral or parenteral nutritional support therapy is recommended.