1. Maintain normal weight To prevent breast cancer, the ACS recommends that women get at least 150 minutes of moderate physical activity per week, drink up to one alcoholic beverage per day, and maintain a BMI <25 kg/m2. In a clinical trial study that included 2905 women at high risk for breast cancer, the risk of breast cancer in this population was reduced by 44% after receiving the ACS recommendations. The Women's Health Initiative Observational Study, which included 64,000 women, found that a healthy diet (more vegetables and fruits, less meat, and less alcoholic beverages) significantly reduced the risk of breast cancer in women with a BMI <25 kg/m2 by 20% and a BMI=25-29.9 kg/m2 by The risk of breast cancer was reduced by 20% in women with BMI <25kg/m2 and by 30% in women with BMI=25-29.9kg/m2. However, it is important to note that a healthy diet does not reduce the risk of breast cancer in obese women. This is because BMI itself is a risk factor for cancer development. Excess body fat triggers insulin resistance, and elevated levels of insulin and growth factors promote the development of cancer. Obesity also promotes the production of estrogen, which in turn promotes the development of many cancers, and fat also secretes cytokines that promote inflammation. A recent dose-response meta-analysis, which included 50 prospective observational studies, found that maintaining a normal weight in adults may prevent certain specific types of cancer, particularly those for which hormone replacement therapy (HRT) is not indicated. The study found that for every 5 kg increase in body weight in adult women, there was a corresponding 11% increase in the risk of postmenopausal breast cancer, a 39% increase in the risk of endometrial cancer, and a 13% increase in the risk of ovarian cancer. For every 5 kg increase in body weight of adult men, the risk of colon cancer increases by 9%, and the risk of kidney cancer is 1.42 times higher than that of normal weight adult men. The biggest problem we face is that the weight of adults increases with age. 2. Exercise at least 30 minutes a day Several observational studies have found that physical exercise can reduce the risk of breast cancer, colorectal cancer and endometrial cancer. A prospective cohort study of U.S. and European populations found that people who exercised to the minimum recommended level of exercise (metabolic equivalent (MET) of 7.5-15 per week) had a 20% lower risk of cancer death compared to those who lacked exercise. 2015 ASCO annual meeting, Professor Donald Abrams of the University of California pointed out that exercise can improve cancer patients' prognosis. A recent meta-analysis of breast and colorectal cancer survivors found that active exercise reduced mortality from breast and colorectal cancers in survivors. Therefore, it is more important for cancer patients to adopt these cancer prevention recommendations after receiving treatment. 3. Eat more vegetables, fruits, whole grains, beans and other foods In addition to weight control and increased exercise, dietary habits can also influence the occurrence of cancer. A recent meta-analysis of prospective cohort studies containing nearly 1 million people found that eating more fruits and vegetables reduced all-cause mortality and cardiovascular mortality, but was not associated with cancer-related mortality. 4. Limit intake of red meat (such as beef, pork and lamb) and avoid processed meat products In addition, studies have found that red meat is not as bad as we thought, at least in terms of carcinogenesis. The results of the European Prospective Survey on Cancer and Nutrition, which surveyed 450,000 people, show that the public is concerned about whether processed meat products increase the risk of cancer. One study found that eating an additional 50g of processed meat products per day increased the risk of cancer by 11%, but the study did not find an association between red meat and the risk of cancer. Thus, it is processed meat products rather than red meat that should be brought to your attention. 5. Limit the daily intake of alcoholic beverages Heavy alcohol consumption (more than 5 standard drinks per day) is strongly associated with the development of 10 types of cancer: oropharyngeal cancer, esophageal squamous epithelial cancer, breast cancer, laryngeal cancer, colorectal cancer, liver cancer, stomach cancer, gallbladder cancer, pancreatic cancer, and lung cancer. Even small amounts of alcohol (1 standard glass of alcohol per day) can increase the risk of oropharyngeal, esophageal squamous epithelial and breast cancers. In addition, it cannot be ignored: non-drinking is associated with overall mortality, as there is a tendency to increase cardiovascular incidence in patients who do not drink alcohol. A recent randomized clinical trial examined whether consumption of vitamin supplements in a healthy population could reduce the risk of cancer. However, the study brought thought-provoking results. Folic acid increased the risk of cancer, especially prostate and colorectal cancer; beta-carotene increased the risk of lung and stomach cancer; selenium increased the risk of non-melanoma skin cancer; and vitamin E increased the risk of prostate cancer. In summary, obesity, lack of exercise and excessive alcohol intake are the factors we should focus on. The evidence on the effect of dietary habits on cancer development is not sufficient, and further in-depth studies are needed to better determine the relationship between the two.