Colorectal cancer is the most common gastrointestinal tumor, ranking third among malignant tumors in the United States, and its incidence is increasing as people become more sophisticated. Numerous prospective and retrospective epidemiological studies have demonstrated that overweight and obesity are associated with the development of a variety of digestive and other systemic tumors. Studies have shown that factors such as body weight, caloric intake, and exercise independently influence the development of colonic adenomas and the carcinogenesis process. Some prospective studies and case-control trials suggest that overweight is a high risk factor for colon cancer, and that a patient’s body mass index (BMI) of >30 increases the risk of colon cancer, and the risk increases with age, and this risk factor is more pronounced in men. The incidence of colon cancer was found to be positively associated with waist circumference in both men and women, and this effect was more pronounced in subgroups that were less physically active. One study found that the incidence of colon cancer was significantly higher in cities, especially large cities, than in small towns and rural areas. In cities, the incidence rate was again higher in those with low physical activity than in those with high physical activity. This is mainly because these people are accustomed to the “two highs and one low”, i.e. high fat, high protein and low dietary fiber diet structure, plus too little exercise, resulting in slowing down of gastrointestinal motility, which not only causes obesity, but also easily causes constipation. Long-term constipation will cause toxins to stay in the body for a long time, so that the body again absorbed, which contains many carcinogenic substances. In addition, obesity, diabetes or glucose tolerance abnormalities, hypertension, dyslipidemia are metabolic diseases, obesity and the above-mentioned other diseases are often accompanied by the onset, if a variety of metabolic diseases appear as a group of clinical syndrome, clinically can be called metabolic syndrome. With the progress of human civilization, urbanization, population aging, diet structure and lifestyle changes, the prevalence of metabolic diseases in the population is increasing year by year. The author’s study of 507 colorectal cancer patients admitted to the Department of Gastrointestinal Surgery of Peking University People’s Hospital from January 2002 to March 2007 found that there were significant differences in the incidence of the presence of more than two, more than three, and more than four metabolic diseases in the colorectal cancer study group compared with the normal human control group, which showed that patients with more than two metabolic abnormalities (e.g., obesity, diabetes, hypertension, dyslipidemia Abnormalities) may be more alert to the occurrence of colorectal cancer, and when atypical symptoms such as blood in stool and change in stool habit occur, especially when they are over 40 years old, they should undergo comprehensive examinations such as colonoscopy in time to detect the lesions early and should not be ignored. Obesity is the evil result of eating more and moving less. We should establish a good lifestyle and diet, avoid eating high-fat food for a long time, eat more fiber-rich food, increase exercise, and keep the bowel movement smooth, so as to reduce the risk of colorectal cancer.