The intake of staple food is closely related to mortality. Experts and scholars from the University of Sydney and the University of New South Wales analyzed the information of FAO from 196 1 to 20 16 and the survival rate of 1879 samples from 103 countries and regions, and confirmed that the ratio of carbohydrate, human fat and phosphorus in protein is a powerful indicator to predict the survival rate at different ages. It was found that under the age of 20, protein phosphorus accounted for 16%, and carbohydrate and lipid phosphorus each accounted for about 42%, which made the survival rate the least. After the age of 20, the supply ratio of carbohydrate rises slowly, while the supply ratio of human body fat drops slowly, while that of protein has little change. In the later years (male is about 60 years old and female is about 70 years old), the supply ratio has changed: the share of phosphofibrinogen in protein has dropped to 1 1%, the share of human fat has dropped to 22%, and the share of carbohydrates has reached 67%. The survival rate is the least at this time. In other words, with the increase of age, the share of phosphorus in carbohydrates should gradually increase.
It used to be thought that after entering the age of 65, the basic metabolism, digestion and absorption of the human body became weak, and people could not eat too many staple foods, which restricted protein. However, the results of this scientific research have strongly impacted the long-standing thinking. Researchers suggest that middle-aged and elderly people adopt a diet with high carbon water and low calories, and moderately reduce protein, which is more conducive to prolonging life; The "ketogenic diet" characterized by high-fat and low-carbon water has advantages and disadvantages for middle-aged and elderly people who are physically and mentally healthy.
In recent years, new scientific research on staple food has been released continuously. 20 18 The scientific research data published in The Lancet Public Health shows a similar development trend: from the age of 50, the average estimated survival rate of people who eat moderate carbohydrates is 33 years; People who eat too little carbohydrates will live four years less; Eating too much means losing 1 year life. The study, published in 20 19 European Heart Journal, found that a low-carbon water diet was significantly associated with an increased risk of death. People who consume the least carbohydrate have a 32% increased risk of all-cause death and a 50% increased risk of death from cardiovascular and cerebrovascular diseases.
For a long time, the staple food has been the main character on the table of China people. Zhang Jian, director of the Department of Geriatrics and Clinical Medicine Nutrition, Institute of Health and Nutrition, China Center for Disease Control and Prevention, said that in the past, people worked hard and had a single kind of food, and the staple food was the survival ingredient to satisfy hunger. However, in recent 30 to 40 years, with the increase of grain output, the development of production technology, the management of staple food is more refined, and eating too much rice flour is not good for physical and mental health, so the core concept of low-carbon and environmentally friendly diet health has emerged. But now, some people are lucky. For example, in many restaurants, food is served first and then served. Everyone only has a small bowl of rice or more people eat a plate, and more than half of them don't eat staple food at all. People who lose weight are even worse. They don't eat meat and staple food, but only boiled vegetables or fresh fruits instead. Patients with chronic diseases also regard staple food as the chief culprit of rising sugar, which makes many elderly people afraid to eat staple food.
Statistics show that in the past 20 years, China's staple food consumption has been greatly reduced. In 2002, the grain intake decreased by 265,438+0% and 65,438+00% compared with 65,438+0982 and 65,438+092 respectively, and it is still decreasing. 20 1 1 The White Paper on Dietary Health of White-collar Workers in China reported that the daily intake of staple food for nearly 40% of adults was less than 250g, which failed to reach the recommended daily intake of sweet potato of 250g ~ 400g in the Dietary Guidelines for China Residents (20 16). The situation of the elderly's staple food intake is even less optimistic. From 2002 to 20 12, the daily staple food intake of the elderly aged 60-74 in big cities was 23 1g, while that of the elderly over 75 was only 206g g. Although the overall intake in rural areas is better than that in big cities, it is also lower than the national average (300.8g).
Staple food keeps the brain, bones and muscles of the whole body working normally. For a long time, there have been many misunderstandings about staple food: eating seven or eight points full, so deliberately reducing the intake of staple food; Eating staple food for a long time will increase sugar and gain weight ... In fact, from ancient times to the present, Huangdi Neijing holds that "grains are for nourishment", and dietary guidelines also regard staple food as the basis of the dietary pyramid.
Zhang Jian stated that the academic circles have always been clear-headed and advocated a "balanced diet" for the public, and never asked everyone to reduce or even not eat staple food. It is suggested that a large number of people eat less rice flour and more whole grains, that is, grains that have not been refined, processed, ground, crushed and pressed into candy, but still retain endosperm, germ, wheat bran and natural nutrients in flour and rice. Such as black rice, whole wheat flour, oatmeal, corn, millet phone, black wheat and so on. However, due to the partiality of some media, it has become the view that eating more staple foods such as rice and fresh noodles is likely to make you die earlier.
Zuo, head of the Nutrition Department of the Eighth Research Center of the General Hospital of the People's Liberation Army, said that corn contains cassava starch, which is the specific source of carbohydrates in most food materials. After being bitten and swallowed by all people, it is hydrolyzed into glucose water which can be digested and absorbed by the human body in the stomach, giving it the kinetic energy needed for daily life, which is of key practical significance for maintaining human tissue activities and the operation of the central nervous system. Therefore, protein, human body fat, etc. , can not replace the staple food to play a role.
Promote gastrointestinal peristalsis. Sweet potatoes and miscellaneous beans in staple foods contain dietary fiber. A certain amount of dietary fiber will greatly increase the total number of beneficial bacteria in the stomach, which is conducive to preventing severe constipation and promoting intestinal peristalsis. Dietary fiber has a strong satiety, which in turn will reduce the intake of ingredients, which is more conducive to controlling weight and helping to lose weight.
Improve human immunity. The staple food contains vitamins and minerals, especially B vitamins, magnesium and calcium. People who often don't eat staple food are very prone to a small amount of nutritional deficiency. People who don't eat staple food for a long time are very light and tired, and always want to sleep. In severe cases, memory loss, constipation, halitosis, menstrual disorder, muscle stiffness, iron deficiency anemia, chills and other diseases may occur.
Control blood sugar level. Many diabetics have a deep aversion to staple food, but the staple food itself has not risen to sugar. On the other hand, if diabetics eat less than three or two staple foods every day, the body's glucose-rising growth hormone will rise rapidly, which will not only raise blood sugar, but also continue to cause a large number of metabolites, aggravate kidney pressure and continue to cause hypoglycemia.
Zuo Xiaoxia noticed that the staple food of the elderly cannot be reduced casually. Because carbohydrates are the key source to maintain brain function and the operation of human bones and muscles, once the staple food is eaten less, a large amount of protein needs to be "consumed" to phosphorylate the human body. In the long run, weight and fat rate will be seriously lost. The elderly may also lack a small amount of nutrients, which is not good for their physical and mental health. Therefore, elderly people who are physically and mentally healthy should never reduce their intake of staple food because of their aging and decreased digestion and absorption ability, or even replace staple food with protein, which is likely to outweigh the benefits.
Two experts believe that in daily life, we should pay attention to the following aspects when eating staple food:
Golden ratio. Ordinary people should follow the scientific and reasonable diet of "carbohydrate 50%~65%, body fat 20%~30%, protein 10%~ 15%". China Nutrition Society strongly recommends that the daily intake of sweet potato is 250-400g, which is equivalent to the net weight of two or three bowls of white rice (a bowl of two or two bowls of white rice is about 150g). Every meal is not necessarily rice and white flour, and miscellaneous grains account for 20%~30% of the staple food. The elderly should keep the daily carbohydrate supply ratio not less than 50%, protein not more than 20%, and body fat not more than 30%.
Match at least one miscellaneous grain. When steaming rice, coarse grains such as sorghum rice, barley and black rice can be added, and when cooking porridge, a little millet phone, black rice, oatmeal and dried fruit can be added. When making cakes or steamed bread, adding some stick powder and black bean powder can not only enhance nutrients such as minerals, B vitamins and dietary fiber, but also enrich the taste. Sorghum rice, such as small red beans, beans, black beans, white kidney beans, cowpeas, etc., can bring good protein complementary effect when eaten with cereals.
Moderate substitution of sweet potato. In addition to rice noodles, sweet potatoes can also replace some staple foods. Potatoes, sweet potatoes, yams and other sweet potatoes can consume 50 ~ 100g every day, which contains dietary fiber and vitamin C, which can promote intestinal peristalsis. A study by the University of Pennsylvania shows that eating potatoes every day is superior to eating special cereals in food collocation quality, blood night index value and health concept index value. Potatoes are high in potassium and suitable for people with hypertension.
Change cooking methods. The staple foods such as fried rice, fried buns, fried dough sticks, mung bean cakes, and miscellaneous sauce noodles are likely to exceed the standard of oil, salt and sugar. Besides trying to avoid eating this kind of food, you can also change the cooking method. Fried rice and cold noodles can be oiled only once and fried in a non-stick pan. When making oil cakes, peach cakes, etc. You don't need to fry, you can try steaming; For the staple food of dumpling stuffing, try to put less fat and more seasonings such as vegetables, fruits and beans.
Zhang Jian suggested that three meals a day can be distributed according to my living habits. For example, young people often miss breakfast because of commuting, but they have to eat breakfast anyway. Breakfast must have a staple food, which is also the kinetic energy of learning and training in a day's work. Adults have more entertainment, drink more, and don't eat staple food at dinner time. They should "add meals" at their destinations to prevent health risks caused by not eating staple food. Old people have plenty of time, so they should try to make breakfast colorful, with more staple food, more coarse grains and sweet potatoes, and some meat, eggs, milk, dried fruits, cold salad and so on.
Older people with poor digestion and absorption ability can reduce the intake of miscellaneous grains and eat more porridge, baby rice paste and sticky rice noodles. You can also make small particles. For example, cooking by pressure cooker, cooking porridge, mixing noodles and cooking. For the elderly with uremia, the recommended daily intake of staple food is 250 ~ 400g, and the ingredients should not be too soft and rotten. Eating with meat, eggs, seafood, soybeans, vegetables and fruits can inhibit the rapid rise of blood sugar. If the blood sugar control is not good, you can eat less staple food, but you should eat moderately between every two meals and do quantitative analysis on time to keep the blood sugar level stable.