On 1 Month 17, 2005, the flag of McDonald's "M" was flown at half mast, announcing to the world that Charlie Bell, the former CEO of McDonald's, had died of colon cancer at the age of 44. It is a great pity to die young. However, in addition to sighing, people have added their thoughts on "three highs and one less" fast food. Bell's life is closely related to McDonald's. /kloc-worked in a McDonald's chain store in Sydney at the age of 0/5, became the vice president of McDonald's Australia at the age of 27, and became the CEO of McDonald's in April last year. Hamburgers and French fries have always been Bell's main working meal. Foreign fast food-hamburgers, fried chicken, beef patties, French fries, cola, etc. Known for its high sugar, high calorie, high fat and low cellulose, it is easy to absorb and has little residue. It was widely favored by the public in the west in the past. It is also loved by office workers because of its convenience and quickness. In recent years, it has been found that the "three highs" food has some disadvantages such as overnutrition, obesity, hyperglycemia, blood lipid and even arteriosclerosis, which has aroused people's doubts about foreign fast food. Because "a little" (less cellulose) food is too fine, less residue, and the intestinal environment is unbalanced, resulting in large intestinal obstruction, which in turn leads to constipation, and rotten feces remain in the large intestine. The basic function of gastrointestinal tract is to expel the old and absorb the new, and the digested residue must be excreted in time. Stimulation of cellulose can promote intestinal peristalsis and excretion function. "A little" food is easy to cause constipation, the stool stays in the large intestine for too long, and corrupt bacteria stimulate the large intestine and increase the chance of colorectal cancer. Some studies have pointed out that one third of human excrement is bacteria. These microorganisms grow, decompose and metabolize in the intestine, which will produce toxins harmful to the body over time and cause cancer over time. However, high-fat diet promotes the increase of bile secretion in the liver, and the primary bile acids in bile are transformed into deoxycholic acid and lithocholic acid under the action of intestinal anaerobic bacteria. Deoxycholic acid and lithocholic acid are cancer-promoting substances, which will form cancerous tumors after long-term stimulation. The consensus of current research is that high fat promotes the occurrence of colon cancer and breast cancer. Colorectal cancer is the most common malignant tumor in western countries (Western Europe, North America). The incidence of colorectal cancer in the United States ranks first among all cancers, which has been proved to be directly related to its diet habit of high fat and low residue. There are fewer people suffering from colorectal cancer in Asia, but in recent years, the incidence of colorectal cancer in Japan has increased rapidly. Since the reform and opening up in China, the incidence of colorectal cancer has increased significantly, which is mainly related to the change of diet structure and the westernization of diet. With the improvement of people's living standards, high-fat diets increase, and vegetables, fruits and crude fiber foods are eaten too little, especially young people like to eat foreign fast food and eat too much meat. In addition, the accelerated pace of life, shortened eating time, so that feces can not be excreted in time, so that toxic substances accumulate for a long time and promote the formation of colorectal cancer. In recent years, colorectal cancer in China is on the rise. Among digestive tract tumors, the incidence of colorectal cancer has risen from the fifth and sixth places to the third place after gastric cancer and esophageal cancer. This reminds us to re-examine our living habits and diet structure, or eat less greasy food, eat more simple meals and whole grains, eat more foods rich in fiber, eat more fruits and vegetables, and increase exercise, so as to reduce the incidence of colorectal cancer. People with signs of obesity, constipation, and changing defecation habits, it is best to see a doctor early, check colonoscopy, and then check regularly. Early detection and operation of colorectal cancer can still achieve good results.