Most cancer patients have obvious emaciation or weight loss, and some people suffer from cancer is obvious emaciation. Cancer patients lose weight because the consumption of nutrients is greater than the intake, and the heat energy in the body can't make ends meet, which is the negative balance of heat in medicine. Because cancer cells consume a lot of nutrients in the process of mass reproduction, and cancer cells mainly consume protein in human body, which is completely different from the nutrients needed for normal cell metabolism. Protein consumed by cancer cells during metabolism can only be extracted from muscle protein, so emaciation of cancer patients is manifested as muscle atrophy at the beginning, unlike emaciation caused by other diseases, which starts from fat loss and only appears when it is serious. Another reason for slimming is that cancer cells will produce a lot of toxins in the process of metabolism, which will inhibit the appetite of patients, leading to loss of appetite, reduced food intake and insufficient nutrient intake. In addition, patients who have been diagnosed with cancer often have symptoms such as anorexia, anorexia, nausea and vomiting when receiving radiotherapy or chemotherapy. Some patients will have psychological anorexia because of cancer, which will inevitably make cancer patients thinner. The emaciation of cancer patients also has a great influence on the prognosis. Some people have investigated more than 3000 patients with various cancers and found that the survival time of dieters is less than half that of those who keep their weight normal. Statistics show that the weight loss of lung cancer patients does not exceed 7%, and anticancer drugs are still effective. If the weight loss exceeds 18%, anticancer drugs will not help, not to mention the reaction of thin people to chemotherapy for digestive tract cancer. Therefore, when treating cancer, we must pay attention to the nutritional status of patients. In recent years. Cancer research institutions and therapists all over the world attach importance to nutritional therapy as an important part of improving treatment methods and improving treatment results. Various means to treat cancer, such as surgery, radiotherapy and anticancer chemicals, are a serious blow to patients. Patients need more nutrition if they want to overcome cancer, endure the blow of treatment and repair the tissue damaged by cancer cells. Take lung cancer as an example. For patients who lose more than 6% weight, 50% patients can get curative effect by using anticancer drugs and nutritional therapy, but only 20% patients can get curative effect if they only pay attention to drug therapy and not nutritional therapy. Family members of patients often ask doctors: What should I give the patients? A doctor replied: Give whatever is good. This statement is not entirely correct. Some people have done animal experiments to prove that animals with cancer only supplement nutrition and have no effective treatment. As a result, cancer increases in proportion to weight gain. If animals are forced to eat nutritious food, cancer tumors will increase more obviously. Clinical experience has also proved that for large cancer patients or patients with extensive metastasis, given a high-calorie diet without treatment, patients will have a low fever, and their heartbeat and breathing will be accelerated, which is not good for their condition. Nutritional treatment must be based on the actual situation of patients. Strictly speaking, it must be based on the daily calories needed by patients. The calculation formula is as follows: heat required by the patient (joule) = body weight (kg)? 20+4.60? 106 provide patients with daily calories through diet adjustment. If they have difficulty eating, of course, they need infusion to supplement them. When conditions permit, total parenteral nutrition can be used to play the role of artificial gastrointestinal. The diet of cancer patients, the first thing is to ensure adequate protein. Protein is easy to digest and absorb to make up for the consumption of cancer cells and repair normal tissues. Secondly, fruits and vegetables should be supplemented with necessary vitamins, especially vitamins A, C and E, which can play a good role in preventing and treating cancer. There must also be enough animal fat, which can not only provide more calories for patients. Moreover, some vitamins such as vitamins A, C, D and K must be dissolved in fat before they can be used. Studies have proved that kelp and seaweed can also help eliminate cancer cells and can be eaten properly.