In addition, most vegetables and fruits are alkaline foods, while generally high-protein foods are acidic foods. In people's stomachs, foods such as meat, rice and wheat often produce acidic reactions after digestion, which requires vegetables and fruits to neutralize and maintain the acid-base balance in the body. The ancients put forward the idea of "five dishes as stuffing" long ago, which shows that vegetables have the functions of "filling" and "dredging" the digestive system. Therefore, to have a good appetite and a healthy digestive system, we must often eat more fruits and vegetables. Although eating more meat will lead to many diseases, it doesn't mean that we can't eat any meat at all, because animal protein in livestock meat and poultry meat is an essential nutrient for human body. Not long ago, European scientists concluded that people often eat red meat (beef, pork, mutton, etc. ): Eating red meat regularly will increase the risk of intestinal cancer. Therefore, while ensuring the acid-base balance, it is best to use white meat such as fish, chicken and duck instead of red meat. For those who prefer meat, Professor Li stressed that when eating foods rich in cholesterol, you must mix some vegetables, fruits and beans to increase the excretion of cholesterol, reduce the synthesis and absorption of cholesterol in the body and avoid the occurrence of atherosclerosis. Starch food mainly inhibits intestinal cancer in two ways: first, after starch enters the intestine, it helps to increase feces, promote colon excretion and accelerate the excretion of carcinogenic metabolites. Secondly, starch can produce a large number of butyrate through the action of intestinal fermentation enzymes. Experiments show that butyrate is an effective cancer cell growth inhibitor, which can directly inhibit the proliferation of bacteria in the large intestine and prevent the generation of cancer-causing cells on the inner wall of the large intestine. How to choose starchy food in life? For busy office workers, roughing whole grain foods such as cereal bread in supermarkets is the first choice. Pay attention to recognition when buying cereal bread: if the first ingredient in the ingredient list is cereal, it means that its cereal content is really rich; If the cereal ingredient ranks behind other ingredients or sugar, it means that there are not many cereal ingredients in this food. Another way is to hold the bread in your hand. If you feel that bread is dense and has obvious grains, it is bread rich in grains. Besides cereal bread, rice made of noodles, bean jelly, pancakes, steamed dumplings and buckwheat is also a good choice. Five-grain porridge rich in B vitamins and vitamin E, such as Laba porridge, Babaolian porridge and lotus leaf porridge, is more suitable for middle-aged and elderly people. Second, the choice of health care products for the elderly: health care products have health care functions, but eating health care products unscientific will not only have no health care effect, but also damage the health of the elderly. If you don't take health care products as needed, it will lead to some functional disorders and other side effects. For example, vitamin A, which is not easily excreted, may sometimes be poisoned. Some Chinese herbal medicine supplements, if eaten too much, will cause poisoning, liver damage and other consequences because of their medicinal properties. Some health care products add a certain amount of hormones, so users must pay attention to the overall balance. Too many hormones are very harmful to health. Health care products are not for the purpose of treatment, but for preventing diseases and maintaining health, and are suitable for specific people, such as sub-healthy people and people with vitamin deficiency. Therefore, health care products can not be used as a substitute for daily diet, and the elderly should pay special attention. Therefore, it is suggested that the elderly can take some calcium-supplementing drugs and health products. If it is iron deficiency anemia, in addition to increasing the absorption of iron from food, they can also eat some iron-containing health products. However, iron supplementation should be carried out under the guidance of a doctor, because iron is not easy to be excreted, and excessive iron supplementation will lead to iron poisoning. Also, exercise moderately, but not vigorously.