Nutritional disorders caused by inadequate or excessive intake of nutrients in the diet are closely related to the occurrence of malignant tumors. Excessive caloric intake not only tends to lead to obesity, but also increases the incidence of cancer. Carbohydrates are the main source of calories, and excessive intake will lead to excess calories. Fat is also a source of calories. Data show that: breast cancer, colon cancer, rectal cancer, endometrial cancer, ovarian cancer, prostate cancer, gallbladder cancer and other seven types of cancer and excessive intake of fat. Fried food, especially fried meat food, will contain carcinogenic heterocyclic amine compounds, should not be eaten more. Fiber can stimulate intestinal peristalsis, accelerate fecal emptying, reduce the contact time between carcinogens and the intestinal wall, and reduce the occurrence of cancer. Vitamin A, vitamin C and vitamin E have an inhibitory effect on carcinogens. Vitamin A, vitamin E exists in meat, eggs, fat, vitamin C exists in fresh vegetables and fruits. Eating more vegetables and fruits, and eating meat, eggs and fat properly can reduce the occurrence of cancer. The trace elements selenium and molybdenum have cancer inhibiting effects. Seafood contains more selenium, and molybdenum is mainly found in grain and drinking water. Some components in tea have anti-cancer activity, so drinking tea properly is good for health.