In essence, it is some sugars, not only the sugars we usually eat, but also polysaccharides, disaccharides and monosaccharides. Polysaccharide is the staple food such as rice, noodles and starch that we are not hungry at ordinary times; Disaccharide refers to common sugar, white sugar and maltose; Monosaccharides are glucose and fructose, and glucose is the most familiar. If you are sick, you will lose some glucose if you don't eat, because glucose is most easily absorbed by the human body and plays a direct role.
Carbohydrate is the most important nutrient to supply human energy. People have the ability to do things through energy. Without energy, people cannot move. Carbohydrate is the most economical food to provide energy for human body. First of all, it is cheap and the most economical. Secondly, it is completely oxidized in the human body and decomposed into carbon and water. Third, it can supply energy quickly.
2. protein:
Is the foundation of human life, there is no life without protein. Protein is the main component of human muscles, blood, viscera, nerves, bones, ligaments, hair, nails and skin. Many active substances related to human life activities, such as enzymes, antibodies, hormones, etc., are composed of derivatives from protein or protein. There are thousands of enzymes in the human body, although the amount of enzymes is small, it is indispensable, otherwise the metabolism of the human body will not be carried out. Protein can be divided into high-quality protein and ordinary protein. High-quality protein is a protein that can not only promote health but also promote growth and development. It contains eight essential amino acids (leucine, methionine, lysine, phenylalanine, tryptophan, threonine and valine). Protein in food is decomposed into amino acids through digestion, and then they are absorbed and distributed through the blood. Essential amino acids cannot be synthesized by human body, but must be taken from food, and the main amino acids are obtained from animal protein. For example, there is no lysine in the grain, which means there are no essential amino acids in the grain.
3. Fat:
Lipids, to be exact. What we eat in our daily life is neutral fat, which is triglycerides, such as oil. Fat consists of 1 molecule glycerol and 3 molecules fatty acid. Fatty acid is a long carbon chain, in which chemical bonds are divided into single bonds and double bonds. Fatty acids contained in fat include saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids (dual-purpose people have more than double bonds). Tea oil in vegetable oil contains more than 80% monounsaturated acids, and corn oil contains polyunsaturated fatty acids. Polyunsaturated acids are most beneficial to human health and can reduce arteriosclerosis and coronary heart disease. Polyunsaturated fatty acids cannot be synthesized by human body and must be taken from food.
Edible oil contains N-3 series unsaturated fatty acids, the former is 18C dienoic acid, and the latter is 20C pentaenoic acid. Linolenic acid is an N-6 unsaturated fatty acid, which can prevent platelet deposition and reduce plasma total cholesterol, and is beneficial to cardiovascular diseases and coronary heart disease in the elderly.
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The above three nutrients are three macro nutrients needed by human body, and there are three proportions in supplying human energy:
Carbohydrate accounts for 55%, protein accounts for 15%, and fat accounts for 20-25%, which cannot exceed 30%. Too much is easy to get chronic diseases.
4. Micronutrients:
Namely inorganic salts and trace elements. Through several national nutrition surveys, let me talk about several elements that our human body is easy to lack:
Calcium: It is an ingredient for building bones and teeth, which affects the growth and development of young children. However, the intake of China people is less than 50% of the amount needed by the human body. Therefore, it is an excellent business opportunity for merchants to identify calcium health products, and all kinds of calcium products are overwhelming. But the best source of calcium is not health care products, but drinking milk. 104 ~ 1 14mg milk contains calcium and 3.4 ~ 3.6mg high-quality protein, which has high absorption rate. There is a saying that drinking milk causes flatulence. I think this is the reason why there are many people who are intolerant of lactic acid in China.
Iron: Iron is an essential component of hemoglobin and myoglobin, and it is also a biologically active part of many enzymes. Anemia occurs when there is iron deficiency, which is called iron deficiency anemia. Iron deficiency in human body will affect the production of hemoglobin (formerly called hemoglobin). This situation is common in China, especially for infants and pregnant women. Iron deficiency anemia is a worldwide nutritional deficiency, even in developed countries, especially pregnant women, lactating women and developing teenagers. Iron in animal food is easily absorbed, and the absorption rate can reach 20%. The absorption rate of iron in plant food is generally around 5%, because it contains plant acid.
Zinc: Zinc is also an important component of many enzymes or can only be activated with zinc. Zinc is very important because it is related to hundreds of enzymes in human body. Children with zinc deficiency don't grow easily, and their hair turns yellow. There is also an obvious food, now called pica. Eating things like bark, grass roots, and soil that you didn't eat originally will also affect the reproductive system and cause rickets. Of course, it's not that serious in China. It should be noted that some places always let children check zinc for you. In some places, it is not so casual, the operation is very strict, and there will be errors in sampling position and sample processing. It must be done in a formal and strict way.
Iodine: iodine deficiency, some places are big neck, called endemic goiter, which is generally not easy in big cities, mainly in some mountainous areas. There is also the mother's lack of iodine, and the children born are all stupid and deaf. Some are not tall, and they are not as tall as five or six years old when they are teenagers. Their mothers still hold them, and they were born with Dingke's disease due to iodine deficiency in the fetus, which seriously caused rough skin. There have been great improvements in these years, and there are many improvements. First, the country has promoted iodized salt, and the salt eaten has been iodized. Then, with the improvement of living standard, the intake of protein increased, and the absorption rate was improved and increased. But it should be noted that you should not eat too much iodine. There is a problem of insufficient and excessive trace elements, because the demand for trace elements is very low, for example, iodine needs 150 micrograms per person per day, which is very small. The limit of trace elements and poisoning are very small. Unlike carbohydrates and protein, if you eat too much, nothing will happen, but if you eat too many trace elements, it will be dangerous. Iodine poisoning happened in our country.
Selenium is a component of an antioxidant enzyme (glutathione peroxidase) in human body. Unlike zinc, only this enzyme is related to selenium. However, this enzyme is very important, which can resist aging and cancer, remove free radicals, reactive oxygen species and other peroxides in the body, and protect the cell membrane from being destroyed. So it causes aging and cancer, that is, cells are destroyed and DNA is destroyed and mutated. It can resist oxidation and reduce proton peroxidation. So it is a very important enzyme, which is very important for the elderly, but the demand is also very low, that is, 200 to 400 micrograms. So don't overdo it, or there is a danger of poisoning. Enshi, Hubei Province is a high selenium area, and selenium poisoning occurs from time to time.
There are fourteen kinds of trace elements, and we only mentioned four that are easy to lack.
5, vitamins:
Vitamins are divided into fat-soluble vitamins and water-soluble vitamins.
? Fat-soluble microbial growth factor: dissolved in fat, it contains vitamin A, β-carotene (which has the same physiological function as vitamin A and can be converted into vitamin A in vivo), vitamin D and vitamin K, which are easily deficient in human body. Vitamin A mainly comes from animal food, and the liver is the most abundant. Vitamin D and β -carotene are plant-based and come from colorful vegetables and fruits, so it is best to choose colorful vegetables.
The main physiological function of vitamin A is related to the eyes. Without vitamin A, it is easy to get night blindness. I can't see clearly at night and have poor adaptability to the darkness. Then it is related to the skin and mucosa. Skin lacks vitamin A, hair follicles become hard, the touch is rough, mucous membranes are damaged, children lack vitamin A, and respiratory tract is easy to be infected. It is also related to the growth and development of children. Young people are prone to blindness.
Vitamin d deficiency is easy to get rickets, which is equivalent to the role of hormones in the body. Vitamin D is active only when it is converted into 25- hydroxyl in the liver, and then becomes E-25- hydroxyl in the kidney, which mainly promotes bone metabolism and affects calcium absorption when it is deficient. Excessive vitamin a and d can also cause poisoning.
Fat-soluble vitamins can be stored in the liver, so too much intake can lead to poisoning. At present, the average annual demand of vitamin A is 800 ~ 1000 micrograms. Vitamin D is 10 microgram. Vitamin D is generally not lacking in adults, because there is a substance under the skin called 7- dehydrocholesterol, which will be converted into vitamin D after being irradiated by ultraviolet rays from the sun. Therefore, because children rarely go out, they are easy to lack, and most of them happen to children under 3 years old.
Another fat-soluble vitamin is vitamin E, which is a good antioxidant vitamin. The elderly take one pill a day, which is beneficial to anti-aging and anti-oxidation. It mainly exists in vegetable oil, especially in germinated vegetable oil such as soybean oil and corn oil. Another is vitamin K, which is generally not easy to lack, mainly during pregnancy, which will cause intracranial hemorrhage in newborns. Just add it.
Water-soluble vitamins: one is group B, but there are more than a dozen in a big family, and the other is vitamin C.
Group B is easy to lack B 1, which mainly exists in cereals, beans and lean meat. Because the particles are getting finer and finer now, it is easy to lack B 1. Vitamin B 1 deficiency occurred in infants in the past, because the mother herself lacked vitamin B 1 during pregnancy and vitamin B 1 in milk, which led to heart failure and stopped beating. It is different from the symptoms of adults, but it is related to nerves. Numbness of hands and feet affecting peripheral nerves, etc. So when eating food, don't be single, try to eat coarse grains and coarse grains. Then there is vitamin B2, also called riboflavin, which mainly exists in the internal organs of animals, such as liver, kidney and intestine. Intake has been insufficient. It is a component of coenzyme, and the deficiency causes a wide range of symptoms, such as angular stomatitis (whitish), glossitis (the lines of the tongue are particularly like maps), bursitis and so on. Nicotinic acid is not easy to lack, and it has been lacking in some areas. In the past, Xinjiang mainly ate corn, which lacked tryptophan, and tryptophan was converted into nicotinic acid in the body. Symptom is symmetrical dermatitis, but it is rare. Then there are folic acid and B 12. Folic acid deficiency is easy to cause megaloblastic anemia. Vitamin B 12 deficiency is easy to suffer from pernicious anemia, and at the same time, it can prevent the formation of cystine. It is good to supplement some folic acid and B 12 appropriately.
Vitamin C is an antioxidant vitamin, also called ascorbic acid. If lacking, blood vessels will become brittle, slightly touch bleeding, gingival bleeding and so on. , the body's resistance will decline.
Second, the nutrition in food:
Animal food: contains high-quality protein, fat-soluble vitamins, trace elements and inorganic salts. Its advantage is that it is easily absorbed by human body; The disadvantage is that the fat contained is saturated fatty acid. However, fish contain unsaturated fatty acids, especially deep-sea fish, which contain more than 17% of high-quality protein.
Eggs: It is a good protein, but yolk contains high cholesterol and egg scales, which can lower cholesterol. An egg a day for the elderly should be no problem.
Soybean: refers to soybeans, mung beans, black beans, etc. , mainly soybeans, such as tofu, qianzi and Zhang Qian, are all made of soybeans. Protein is a high-quality protein with a content higher than that of meat, reaching over 30% (lean meat only contains over 20%). Among plant foods, only soybeans contain high-quality protein. If eaten with whole grains, it can also play a supplementary role in protein. Soybeans also contain nutrients such as inorganic salts.
Vegetables and fruits: mainly the only source of water-soluble vitamins and inorganic salts, especially vitamin C, which is easily destroyed by oxidation, so be sure to fresh vegetables. The content of stale vegetables is very low, which is related to cooking methods. For example, in order to keep vegetables green, add alkali or fish with water before frying, and vitamin C will be destroyed or all of them will enter the water. The content of β -carotene in colored vegetables reaches 3 ~ 4 mg, which is 400 micrograms, that is, the conversion rate in the body is 1/6, which is quite a lot.
Miscellaneous grains: contain vitamin B, especially millet, with high content of beans. Zinc mainly exists in the epidermis of coarse grains (the finer the particles, the greater the loss), and the highest content is shellfish, such as oysters.
Vegetable fat: polyunsaturated fatty acids, in addition to vegetable oils such as soybean oil, there are also dried fruits and nuts, such as peanuts and walnuts.
Iron: Animal food has a high iron absorption rate, while plant food has a low absorption rate.
Selenium: It is mostly contained in bacteria and algae foods, with high content, such as mushrooms.
In addition, I looked up some information about medicinal and edible plants. I don't know Chinese medicine, but from a nutritional point of view, many of them have high nutritional value. For example, the content of β -carotene in Lycium barbarum is as high as 9750 μ g/ 100 g, and vitamin A1635 μ g should be supplemented after eating for half a day; The content of β -carotene in fresh cassia seed is as high as 4350 μ g/100g, equivalent to 725 μ g of vitamin A; Schisandra chinensis contains β-carotene 15080 μ g/ 100 g, and the content of plantain seeds is as high as 6170μ g. The calcium content is very high, many of them are above 300mg, and licorice contains 832mg/100g. Mint contains 340 mg; Schisandra chinensis contains 360mg；; Plantain seed contains 370 mg; Cassia seed contains 3 10 mg. Chinese herbal medicine is rich in trace elements. Licorice contains 2 1.2 mg of iron and 5.88 mg of zinc, which is rare in food. Licorice contains 4.72 micrograms of selenium, safflower contains selenium 1 1.3 1 micrograms, and the animal medicine Trionyx sinensis contains selenium 1 13.5 micrograms. Chinese medicine may have a better explanation. From the point of view of nutrition, Chinese herbal medicine contains high content of vitamins and trace elements, which accords with the point of view of nutrition.
Third, a balanced diet:
A balanced diet means eating all kinds of food, and the amount of food should be appropriate, so as to achieve balance and make nutrition meet the needs of the human body. The Nutrition Society of China has formulated a guide to balanced diet for China residents. All kinds of food are in the shape of pagodas: tell us how much we should eat every day. The bottom of the tower is the most abundant, mainly food or staple food. We can't live without food, which is starch. Eating 300 ~ 500 grams of grain every day depends on age, sex and labor intensity.
The second layer, relatively rich, is vegetables and fruits, which supply us with vitamins and trace elements. Vegetables eat 400 ~ 500 grams a day, and more than half of them are colored vegetables. Then eat fruit 100 ~ 200g/ day. Now fruit is cheaper than vegetables.
? Animal foods, including the meat of livestock, poultry, chickens and ducks, add up to 50 ~100g a day; Then fish and shrimp, also 50 ~ 100g/ day. In order to ensure iodine intake, you can eat more seafood, such as kelp, seaweed and other foods with high iodine content. It is more appropriate for the elderly to eat less meat and more fish.
? Eggs: 20 ~ 50g/ day. There are only one or two big eggs now. Old people are afraid of high cholesterol. Just eat one every two days.
Milk and dairy products: I think it's enough now. I can eat 100 ~ 200g/ day.
? Beans and bean products: Eat 50 ~ 100g/ day, depending on the situation. Older people are not suitable for eating more meat, but can eat more beans and their products, because they mainly supply high-quality protein like animal food.
Grease: At the top of the tower. Refers to edible oil and vegetable oil, excluding animal food itself. 25 grams a day on average. These are not what everyone has to count every day, but a balanced amount. At the end of the week, you should know what you are doing and reach this balanced figure. Don't eat whatever you want.
It is better to eat coarse grains or miscellaneous grains properly. Another is animal liver, which many people dare not eat. In fact, it is a nutritious food, such as vitamin A and iron. The disadvantage is that cholesterol is relatively high, but it is much lower than egg yolk (egg yolk is above 800 μ g/100g). You can eat it once a week. There are thousands of micrograms of vitamin A once or twice. People only need 800 micrograms a day, so just eat a little to meet their needs.
Salt: Don't exceed 6 grams a day. Eat less salt, drink less, and drink low-alcohol if you want.
Having said so much, nutrients are not easy to master, and it is impossible to look up books to eat, but you must have a basic understanding. A light worker, female, needs 2000 ~ 2 100 kcal a day; According to the percentage of energy supply, fat is 65 ~ 70g/ day in protein, calcium is 800mg/ day in adults and 1000 ~ 1200mg/ day in adolescence. Vitamin A800 micrograms; Vitamin B 1 is 0.5 mg/1000 calories according to energy calculation, a little more is ok, but not too little, and so is vitamin B2; Iron adults 12mg/ day, slightly more women, adolescent girls 18 mg, pregnant women more than 20 mg; Zinc 15mg/ day; As long as you have a concept and follow this balanced diet, you can meet the needs of your body.