Nutrient refer to the chemical components in food that can provide energy for human body, repair the body and tissues, and have physiological regulation functions. All substances that can maintain human health and provide for growth, development and labor are called nutrients. The essential nutrients for human body include protein, fat, sugar, inorganic salts (minerals), vitamins, water and cellulose, and many non-essential nutrients.

water

Water is the source of life, and people's need for water is second only to oxygen. Water is a necessary substance to maintain life, and the body's material metabolism and physiological activities are inseparable from the participation of boiling water. The important component of human cells is water.

Seven nutrients

The water content of adults is about 70%, that of infants is about 80%, and that of the elderly is 55%. Every kilogram of body weight needs about 150 ml of water every day, and most of breast milk is water, so the feeding water for breast feeding should be adjusted appropriately. The water requirement can be obtained by multiplying 150 ml by the kilograms of body weight, and then subtracting the milk intake, the amount of water to be fed can be obtained.

Water comes from all kinds of food and drinking water. If people don't take a certain vitamin or mineral, they may be able to live for several weeks or years with illness, but if they don't have water, they can only live for a few days. Water is beneficial to the chemical reaction in the body and also plays the role of transporting substances in the living body. Water plays an important role in maintaining the stability of biological temperature. [ 1]

protein

Protein is an indispensable substance to sustain life. Human tissues and organs are composed of cells, and the main component of the cell structure is protein. Protein plays a role in the growth of the body, the repair of tissues, the regulation of various enzymes and hormones on biochemical reactions in the body, the composition of antibodies against diseases, the maintenance of osmotic pressure and the transmission of genetic information. Infants and young children grow rapidly, and protein needs more than adults, with an average of more than 2 grams per kilogram of body weight every day. Meat, eggs, milk and beans are rich in high-quality protein and must be provided every day. note:

1, the principle of collocation, such as the collocation of animal and plant foods; The collocation of many kinds of food.

2. The principle of not providing too much. The protein calories in infants should account for12% ~14% of the total calories. Too much will affect the normal function of protein, cause protein consumption and affect the nitrogen balance in the body.

3. The principle of providing less. Too little supply from protein obviously affects the growth and development speed, biochemical reaction, disease resistance and even malnutrition. As a result, it not only causes growth backwardness, but also affects the development of brain cells, resulting in mental retardation.

fat

vitamin

Fat is the main nutrient for storing and supplying energy. Each gram of fat provides twice as much heat energy as the same weight of carbohydrates or protein. The composition of cell membrane, nerve tissue and hormone of the body can not be separated from it. Fat also keeps warm and insulated; Support the protection of internal organs, joints and various tissues; Promote the absorption of fat-soluble vitamins. Babies need 4 grams of fat per kilogram of body weight every day, and fats from animals and plants are necessary for human body and should be provided together. Daily fat heating should account for 20% ~ 25% of the total calories.

Lipid refers to a class of substances that are quite different in chemical composition and structure, but all have the same characteristic, that is, they are insoluble in water and easily soluble in non-polar solvents such as ether and chloroform. Generally, lipids can be divided into five categories according to different compositions, namely, simple lipids, complex lipids, terpenoids and steroids and their derivatives, derived lipids and bound lipids.

Lipids have important biological functions, and fat is the energy provider of organisms.

Lipids are also important components of organisms, such as phospholipids, which are important components of biofilm, and oils are the storage and transportation forms of fuel needed for metabolism. Lipid substances can also provide essential fatty acids and fat-soluble vitamins dissolved in animals. Some terpenoids and steroids, such as vitamins A, D, E, K, cholic acid and steroid hormones, have nutritional, metabolic and regulatory functions. Lipid substances on the surface of organisms have protective effects such as preventing mechanical damage and preventing heat emission. As the surface substance of cells, lipids are closely related to cell recognition, species specificity and tissue immunity.

carbohydrate

Food Pyramid

Carbohydrate is the main nutrient that provides energy for life activities. It widely exists in rice, flour, potatoes, beans and various miscellaneous grains, and is the most important and economical food for human beings. The daily calories provided by this kind of food should account for 60% ~ 65% of the total calories. Any carbohydrate will eventually decompose into sugar after biochemical reaction in the body, so it is also called sugar. Besides supplying energy, it also promotes the metabolism of other nutrients, and combines with protein and fat to form glycoproteins and glycolipids, forming substances with important functions, such as antibodies, enzymes, hormones, cell membranes, nerve tissues and ribonucleic acids. The importance of this kind of food is self-evident, but parents should also be reminded not to add too much rice noodles too early; Adding too much sugar to children's food will lead to obesity and lay a curse for their future health.

Cellulose is an undigested carbohydrate, but its function cannot be ignored. Cellulose can be divided into water-soluble and water-insoluble. Water-insoluble fibrin is not digested and absorbed by the human body, but only stays in the intestine, which can stimulate the production of digestive juice and promote intestinal peristalsis, absorb water and facilitate defecation, and also play a beneficial role in the establishment of intestinal flora; Water-soluble cellulose can enter the blood circulation, reduce the plasma cholesterol level, improve the blood sugar production reaction, and affect the absorption speed and location of nutrients. Fruits, vegetables, cereals and beans all contain more cellulose for parents to choose from.

vitamin

Vitamins play an important role in maintaining human growth and physiological functions, and can promote the activity of enzymes or be one of coenzymes. Vitamins can be divided into two categories. One category is fat-soluble vitamins, including Vit.A, D, E and K, which can be stored in the body and do not need to be provided daily, but excessive doses can cause poisoning; The other is water-soluble vitamins, including vitamin B and vitamin C, which account for the majority. They are not stored in the body and need to be provided from food every day, so they are not easy to be poisoned because of their rapid metabolism. The other is fat-soluble vitamins, which can be stored in human liver. Vitamins A, D, B, C, E, K, folic acid ... all perform their duties and are indispensable, and can help the human body to play a certain role in resisting the absorption of substances. Therefore, it is particularly necessary to provide children with fresh vegetables, fruits, livers and egg yolks, eat coarse grains properly and get more sunshine.

mineral

Minerals are the main components of human body, with carbon, hydrogen, oxygen and nitrogen accounting for about 96% of the total body weight, calcium, phosphorus, potassium, sodium, chlorine, magnesium and sulfur accounting for 3.95%, and others are trace elements ***4 1 species, and iron, zinc, copper, selenium and iodine are often mentioned. Each element has its important, unique and irreplaceable function, and there is a close relationship between the elements, which accounts for a large proportion in the research of children's nutrition. Although minerals do not provide energy, they have important physiological functions: 1, the main component of bones; 2. Maintain normal physiological functions of nerves and muscles; 3. Composition of constitutive enzyme; 4. Maintain osmotic pressure and acid-base balance. Mineral deficiency is related to diseases, such as calcium deficiency and rickets; Iron deficiency and anemia; Zinc deficiency and backward growth and development; Iodine deficiency, growth retardation, mental retardation and so on should be paid enough attention to.

dietary fiber

There are two definitions of dietary fiber. One is to define dietary fiber as the remains of undigested plant cells in the digestive system of mammals, including cellulose, hemicellulose, pectin, resistant starch and lignin. The other is that dietary fiber is defined as plant non-starch polysaccharide plus lignin from a chemical point of view.

Dietary fiber can be divided into soluble dietary fiber and insoluble dietary fiber. The former includes part of hemicellulose, pectin and gum, while the latter includes cellulose and lignin. Among them, apple collagen, as a natural macromolecular water-soluble dietary fiber, has the function of strongly adsorbing and excluding human "radiation (positive charge substance)" and is an essential nutritional balancer for human body. It has a unique molecular structure and can't be directly digested by human body, so it can naturally absorb harmful substances such as toxins, negative nutrition, heavy metals and free radicals, which are difficult to metabolize themselves, and thus achieve a nutritional balance. Regular consumption of apple collagen can prevent and inhibit cardiovascular diseases, gastrointestinal diseases, respiratory diseases, metabolic diseases and tumors and other human diseases. [