Long-term investigations have shown an increase in cancer due to improper diet. To address the prevention of hair tumors, the relationship between the structure of the diet and the occurrence of cancer must be studied. Calorie balance and intake. Some data show that women with faster development and growth of infants and children, early menarche, high-calorie diet, obesity and less activity have increased risk of breast cancer and endometrial cancer. Obesity may also increase kidney cancer, gallbladder cancer, colon cancer, etc. Carbohydrates. This is a class of compounds with the elements of carbon, hydrogen and oxygen, consisting of sugar, starch and non-starchy dietary fiber, and is currently the main source of dietary calories in most countries and regions of the world. It has been identified that diets high in starch and fiber may have a role in reducing the incidence of colon and pancreatic cancer, such as excessive consumption of refined starches, which can increase the risk of stomach and colorectal cancer. It is fat. Diets high in fat, especially animal fat and saturated fat, may lead to an increased risk of lung, colorectal, breast, and prostate cancers. Vitamins. These are organic compounds that are necessary to maintain the health of the body. Foods high in carotenoids reduce the risk of lung, esophageal, stomach, colorectal, breast and cervical cancers, and vitamin C decreases the incidence of oral, esophageal, stomach, lung, pancreatic and cervical cancers. Vitamin E reduces the risk of lung and cervical cancer. Minerals and trace elements. Food deficiency or high iodine content can increase the risk of thyroid cancer. Dietary supplementation with appropriate amounts of selenium has the potential to reduce the incidence of lung cancer and primary liver cancer. Vegetables and fruits. It provides a rich source of fiber, vitamins, minerals and bioactive substances. Available information proves that vegetables and fruits can reduce the risk of lung, stomach and oral cancer; cruciferous vegetables can reduce the incidence of colorectal and thyroid cancer; garlic, onions, carrots, tomatoes and citrus fruits are beneficial in reducing lung, stomach and bladder cancers. Beans. It is the richest source of dietary plant protein, which also has a large amount of fiber, minerals, vitamins and bioactive substances. Many experimental studies have suggested that soy is as effective a health food as vegetables and fruits in preventing tumors in humans.