Chemotherapy is a treatment method in which chemical drugs are administered into the body through a vein (most breast cancer patients use a central venous line) to kill cancer cells that are invisible to the naked eye. Despite the preventive treatment by clinicians, symptoms such as loss of appetite, indigestion, nausea and vomiting still plague every chemotherapy patient during treatment. More than 50% of tumor patients have different degrees of malnutrition during the treatment period, which will inevitably affect the successful completion of treatment and full recovery after treatment in the long run. During this period of time, the dietary regimen is a problem that patients and their families should pay attention to. The Department of Breast Diseases of our hospital summarizes years of treatment experience, patients at this stage should eat according to the principle of “three highs, one more and one lower”, i.e. high calorie, high protein, high vitamin, more water and low fat. Only under the premise of ensuring sufficient calorie supply, the protein intake can be fully used for the recovery of cell damage after chemotherapy. Water intake should be increased by about 50% to ensure the normal functioning of kidney function and drug metabolism. Problems that often occur in patients at this stage and how to deal with them: 1. Digestive adverse reactions: nausea and vomiting, loss of appetite, constipation, and a few diarrhea are common. Response to loss of appetite: First of all, patients should understand the importance of doing their best during chemotherapy, and adopt the method of eating less and more meals, or take a walk and other activities before meals to enhance appetite; at any time when patients want to eat they should try to meet their requirements for food and cooking methods, pay attention to the color, aroma, taste and shape, and increase the intake of salt in an appropriate amount. Other patients’ sense of taste changes during treatment, so they can choose foods with unique flavors such as mushrooms and onions in their diet, and try not to use foods with heavy bitterness such as bitter melon and mustard. Cold dishes are attractive to patients, but attention must be paid to dietary hygiene, while the choice of tableware that patients like and attention to the eating environment and atmosphere can also help stimulate appetite. Coping with nausea and vomiting: appropriate adjustment of diet structure and meal methods is required. Eat little and often to avoid the feeling of fullness; do not drink too much water during meals, preferably one hour before and after eating; avoid sweet, fried or overly greasy food; the temperature of food should be suitable, not too hot or too cold; avoid disliked odors; sit in a chair to rest after meals, do not rush to lie down; take deep breaths when you feel nauseous. Coping with diarrhea: eat lightly, do not drink milk for a while, and avoid eating foods that are too cold, too hot or irritating. Diarrhea may lose potassium and water, so pay attention to replenish potassium-rich foods, such as bananas, oranges, celery, tomatoes, etc., and also have enough water to drink. Easy-to-digest food can be added after the condition improves. 2, myelosuppression: for the more common complications, but also may be the most serious complications; that is, chemotherapy drugs will kill the white blood cells and platelets in the blood. Before chemotherapy, the doctor will give you lab tests, and if the white blood cells are less than 4,000/L and platelets are less than 70-100,000/L, chemotherapy will be stopped and you must wait for the blood cells to rebound before continuing treatment. 3.Liver function damage: After a certain stage of chemotherapy, the doctor will do laboratory tests for your liver function, and if the liver function is not normal you must also stop chemotherapy and receive liver-protective treatment. 4, kidney function damage: most of the chemotherapy drugs have to be excreted from the kidneys, so a certain amount of drugs will stay in the kidneys and cause kidney damage. Therefore, when you do chemotherapy, you must pay attention to the diet, drink more water, eat more fresh vegetables and fruits, pay attention to rest, and report any adverse reactions to the nurse, who will also closely observe your reactions and make symptomatic treatment at any time.