The principles of proper nutrition. Nutrients and their sources. Basic nutrients, minerals, microelements and their importance in health and disease
Nutrients - carbohydrates, proteins, vitamins, fats, trace elements, macronutrients- Found in food. All these nutrients are necessary for a person to be able to carry out all life processes. The content of nutrients in the diet is the most important factor for compiling a diet menu.
In the body of a living person, the processes of oxidation of all kinds never stop. nutrients. Oxidation reactions occur with the formation and release of heat, which a person needs to maintain life processes. Thermal energy allows the muscular system to work, which leads us to the conclusion that the harder the physical labor, the more food is required for the body.
The energy value of foods is determined by calories. The calorie content of foods determines the amount of energy received by the body in the process of assimilation of food.
1 gram of protein in the process of oxidation gives an amount of heat of 4 kcal; 1 gram of carbohydrates = 4 kcal; 1 gram of fat = 9 kcal.
Nutrients are proteins.
Protein as a nutrient necessary for the body to maintain metabolism, muscle contraction, nerve irritability, the ability to grow, reproduce, and think. Protein is found in all tissues and body fluids and is an essential element. A protein consists of amino acids that determine the biological significance of a protein.
Non-essential amino acids formed in the human body. Essential amino acids a person receives from the outside with food, which indicates the need to control the amount of amino acids in food. A dietary deficiency of even one essential amino acid leads to a decrease in the biological value of proteins and can cause protein deficiency, despite a sufficient amount of protein in the diet. The main source of essential amino acids are fish, meat, milk, cottage cheese, eggs.
In addition, the body needs vegetable proteins contained in bread, cereals, vegetables - they provide essential amino acids.
Approximately 1 g of protein per 1 kilogram of body weight should enter the body of an adult every day. That is, an ordinary person weighing 70 kg per day needs at least 70 g of protein, while 55% of all protein should be of animal origin. If you exercise, then the amount of protein should be increased to 2 grams per kilogram per day.
Proteins in the right diet are indispensable for any other elements.
Nutrients are fats.
Fats as nutrients are one of the main sources of energy for the body, are involved in recovery processes, as they are a structural part of cells and their membrane systems, dissolve and help in the absorption of vitamins A, E, D. In addition, fats help in the formation of immunity and keeping warm in the body .
An insufficient amount of fat in the body causes disturbances in the activity of the central nervous system, changes in the skin, kidneys, and vision.
Fat consists of polyunsaturated fatty acids, lecithin, vitamins A, E. An ordinary person needs about 80-100 grams of fat per day, of which vegetable origin should be at least 25-30 grams.
Fat from food gives the body 1/3 of the daily energy value of the diet; There are 37 g of fat per 1000 kcal.
The required amount of fat in: heart, poultry, fish, eggs, liver, butter, cheese, meat, lard, brains, milk. Vegetable fats, which contain less cholesterol, are more important for the body.
Nutrients are carbohydrates.
Carbohydrates,nutrient, are the main source of energy, which brings 50-70% of calories from the entire diet. The required amount of carbohydrates for a person is determined based on his activity and energy consumption.
On the day of an ordinary person who is engaged in mental or light physical labor, about 300-500 grams of carbohydrates are needed. With an increase in physical activity, the daily intake of carbohydrates and calories also increases. For full people, the energy intensity of the daily menu can be reduced due to the amount of carbohydrates without compromising health.
A lot of carbohydrates are found in bread, cereals, pasta, potatoes, sugar (net carbohydrate). An excess of carbohydrates in the body disrupts the correct ratio of the main parts of food, thereby disrupting metabolism.
Nutrients are vitamins.
vitamins,as nutrients, do not provide energy to the body, but still are the most important nutrients necessary for the body. Vitamins are needed to maintain the vital activity of the body, regulating, directing and accelerating metabolic processes. Almost all vitamins the body receives from food and only a few can be produced by the body itself.
In winter and spring, hypoavitaminosis may occur in the body due to a lack of vitamins in food - fatigue, weakness, apathy increase, efficiency and body resistance decrease.
All vitamins, according to their effect on the body, are interconnected - a lack of one of the vitamins leads to a metabolic disorder of other substances.
All vitamins are divided into 2 groups: water soluble vitamins and fat soluble vitamins.
Fat-soluble vitamins - vitamins A, D, E, K.
Vitamin A- is needed for the growth of the body, improving its resistance to infections, maintaining good vision, the condition of the skin and mucous membranes. Vitamin A comes from fish oil, cream, butter, egg yolk, liver, carrots, lettuce, spinach, tomatoes, green peas, apricots, oranges.
Vitamin D- is needed for the formation of bone tissue, growth of the body. A lack of vitamin D leads to a deterioration in the absorption of Ca and P, which leads to rickets. Vitamin D can be obtained from fish oil, egg yolk, liver, fish caviar. Vitamin D is still found in milk and butter, but just a little bit.
Vitamin K- Needed for tissue respiration, normal blood clotting. Vitamin K is synthesized in the body by intestinal bacteria. The lack of vitamin K appears due to diseases of the digestive system or the use of antibacterial drugs. Vitamin K can be obtained from tomatoes, green parts of plants, spinach, cabbage, nettles.
Vitamin E (tocopherol) is needed for the activity of the endocrine glands, the metabolism of proteins, carbohydrates, and intracellular metabolism. Vitamin E favorably affects the course of pregnancy and fetal development. Vitamin E is obtained from corn, carrots, cabbage, green peas, eggs, meat, fish, olive oil.
Water-soluble vitamins - vitamin C, B vitamins.
Vitamin C (ascorbic acid) - is needed for the redox processes of the body, carbohydrate and protein metabolism, increasing the body's resistance to infections. Vitamin C is rich in rose hips, black currants, chokeberries, sea buckthorn, gooseberries, citrus fruits, cabbage, potatoes, leafy vegetables.
Vitamin B group includes 15 water-soluble vitamins that are involved in metabolic processes in the body, the process of hematopoiesis, play an important role in carbohydrate, fat, water metabolism. B vitamins stimulate growth. You can get B vitamins from brewer's yeast, buckwheat, oatmeal, rye bread, milk, meat, liver, egg yolk, green parts of plants.
Nutrients are micronutrients and macronutrients.
Nutrient Minerals are part of the cells and tissues of the body, participate in various metabolic processes. Macroelements are necessary for a person in relatively large quantities: Ca, K, Mg, P, Cl, Na salts. Trace elements are needed in small quantities: Fe, Zn, manganese, Cr, I, F.
Iodine can be obtained from seafood; zinc from cereals, yeast, legumes, liver; copper and cobalt are obtained from beef liver, kidneys, egg yolk, honey. Berries and fruits contain a lot of potassium, iron, copper, phosphorus.
To live a full life and maintain physical fitness, it is necessary to adhere to the principles of proper nutrition, which implies a well-composed diet that fully satisfies the needs of the body and supplies the necessary nutrients. An insufficient amount of any substances in the body quickly leads to the development of various kinds of diseases. That is why it is so important to make nutrition complete. With food, fats, proteins and carbohydrates, salts, vitamins and minerals should be supplied daily. Moreover, their ratio should be approximately as follows: fats - 20%, proteins - 20%, carbohydrates - 60%. When compiling a daily diet, you need to be guided by the principles on which proper nutrition is based.
The principles of proper nutrition
- It is necessary to divide the daily diet into 4-5 meals. It is this mode that allows you to maintain at a sufficient level, which has a beneficial effect on well-being and appearance.
- It is advisable to eat at a certain time. Compliance allows the body to develop a certain rhythm of functioning, which improves the process of digestion of food and prevents the development of diseases of the digestive system.
- Distribute the calories consumed as follows: breakfast - 25-30%, lunch - 40%, dinner - 15-20%, lunch / afternoon tea - 15-20%. The fourth meal can be either between breakfast and lunch, or between lunch and dinner. It all depends on the daily routine - if you get up early, then a significant period of time passes from breakfast to lunch, and then an additional breakfast (lunch) is what you need. Have an extra meal in the evening if you are a night owl and go to bed late (but no later than 2-3 hours before bedtime).
- Take your time while eating, chew thoroughly - this helps to better absorb the nutrients contained in food.
- Try to diversify your diet, include different foods, combine cooking methods. When preparing food, use cooking methods that preserve nutrients and vitamins. Cook more often in the oven or steam, eat boiled food rather than fried.
In order to properly compose a diet, you need to know which foods contain which substances.
Nutrients and foods that contain them
Squirrels - " building material, necessary for the normal functioning of the body. We get them from plant and animal foods. Sources of origin are legumes (peas, lentils, beans) and nuts. Animal proteins are found in all types of meat, milk and dairy products, fish and eggs.
Different proteins contain different amino acids, most of which are not produced by our body, but are obtained only in the process of digestion of food. Therefore, it is necessary to diversify the sources of protein intake in the body.
Fats- the most valuable nutrients, suppliers of energy to the body. They are also involved in many metabolic processes, and the reserves of fats in the body serve as a "reserve" for an emergency. Sources of fats are also divided into vegetable and animal. Animal fats are obtained from fatty meats and fish, milk and dairy products. Sources are sunflower, olives, corn, etc.
When compiling a diet, you should pay attention to the fact that the main fats are classified as unsaturated - they are most beneficial to the body.
Carbohydrates- the main supplier of energy to the body, they are involved in the formation of enzymes, hormones, secretions of glands and other compounds necessary for life. Carbohydrates are divided into simple and complex. Sources - sweet foods: sugar, honey, wedge syrup and sweet fruits. contain plants: cereals (main source), vegetables and legumes. Excess carbohydrates in the diet can lead to overweight and obesity, but it is impossible to exclude carbohydrates from the diet. With their deficiency in the body, a violation of the metabolism of fats and proteins develops, products of incomplete oxidation of some amino acids accumulate.
The purpose of proper balanced nutrition is to provide the body with nutrients, trace elements and vitamins in accordance with the needs.
Nutrients include proteins, fats, carbohydrates, vitamins, mineral salts and water.
Squirrels. They are indispensable substances. They are not kept in stock. Protein starvation, even with sufficient intake of other nutrients, ends in death. Protein functions:
Plastic;
Energy - in case of excess intake and starvation;
Enzymatic (eg, digestive enzymes, blood coagulation enzymes, intracellular enzymes, etc.);
Transport (for example, hemoglobin);
Regulatory (for example, protein-peptide hormones: insulin, growth hormone, etc.);
The mechanism of muscle contraction;
Protective function (for example, antibodies).
The need for proteins in children is higher than in adults due to high plastic needs. So in newborns, the daily requirement for proteins is more than 4 g / kg of body weight, at 5 years old - about 4 g / kg, at 14-17 years old - 1.5-1.6 g / kg, in adults - 1.1 - 1.3 g/kg.
Fats. They are deposited in the reserve, mainly in the subcutaneous adipose tissue and normally make up 10-20% of body weight. The value of fats:
Plastic;
Energy (about 50% of the energy the body receives from the oxidation of fatty acids. When 1 mole of a fatty acid is oxidized, energy is released that is sufficient for the synthesis of 130 ATP molecules, while when 1 mole of glucose is oxidized, only 36 ATP molecules can be synthesized);
Source of endogenous water (107 g of water is formed per 100 g of fat);
Thermal insulation;
Protective (shock-absorbing);
Absorption of fat-soluble vitamins;
Regulatory (synthesis of hormones of a steroid nature), etc.
The need for fats in children increases with age, mainly due to their plastic value. So, children 1-3 years old need 40-50 g of fat per day, 4-6 years old - 55-60 g. 7-9 years old - 65-70 g. Excess fat in the diet causes metabolic disorders, accompanied by deterioration the use of protein, the deterioration of digestion processes and the deposition of fat in the reserve.
Carbohydrates. Stored as glycogen in the liver and muscles. With excessive intake and overflow of glycogen depots, they can turn into fats and also be stored in reserve. Meaning:
Energy. Especially important for the brain, which consumes 70% of glucose;
Rapidly mobilized energy reserve in the form of glycogen;
Plastic.
The daily requirement for children of younger preschool age is 6 times higher than the need for proteins and fats, for children of older preschool age - 5 times, and for schoolchildren - 4 times. An excess of carbohydrates in the diet is accompanied by a decrease in protein intake, water retention and the formation of fat that is not involved in metabolic processes.
Vitamins. They do not have energy value. They have no plastic value. However, they are vital substances. In the absence (avitaminosis) or deficiency (hypovitaminosis) of these substances in food, severe metabolic disorders, diseases (rickets, scurvy, night blindness, etc.) and even death are inevitable. Hypervitaminosis is no less dangerous. They are rare and have become possible in connection with the production of artificial vitamin preparations. With hypervitaminosis A, inflammation of the eyes, hair loss, headaches, insomnia and nausea are observed; hypervitaminosis D is accompanied by death due to calcification of internal organs, such as the heart, kidneys.
The effect of vitamins on metabolism is due to the fact that they are involved in the synthesis of enzymes, are part of enzyme molecules, i.e. vitamins indirectly (through enzymes) regulate metabolism. For example, vitamin Bı is necessary for the synthesis of 4, and vitamin B6 - 20 enzymes of protein synthesis, vitamin K - for the synthesis of 5 enzymes involved in blood clotting. However, no enzyme systems have been found for some vitamins and a direct biocatalytic function is assumed.
Mineral salts and water– meaning and the need to learn on your own.
The human body consists of proteins (19.6%), fats (14.7%), carbohydrates (1%), minerals (4.9%), water (58.8%). He constantly spends these substances on the formation of energy necessary for the functioning of internal organs, maintaining heat and carrying out all life processes, including physical and mental work.
These are complex organic compounds of amino acids, which include carbon (50-55%), hydrogen (6-7%), oxygen (19-24%), nitrogen (15-19%), and may also include phosphorus, sulfur , iron and other elements.
Proteins are the most important biological substances of living organisms. They serve as the main plastic material from which the cells, tissues and organs of the human body are built. Proteins form the basis of hormones, enzymes, antibodies and other formations that perform complex functions in human life (digestion, growth, reproduction, immunity, etc.), contribute to the normal metabolism of vitamins and mineral salts in the body. Proteins are involved in the formation of energy, especially during periods of high energy costs or when there is an insufficient amount of carbohydrates and fats in the diet, covering 12% of the body's total energy needs. The energy value of 1 g of protein is 4 kcal.
With a lack of proteins in the body, serious disorders occur: a slowdown in the growth and development of children, changes in the liver of adults, the activity of the endocrine glands, blood composition, a weakening of mental activity, a decrease in working capacity and resistance to infectious diseases.
Amino acids according to their biological value are divided into irreplaceable and non-essential.
There are eight essential amino acids - lysine, tryptophan, methionine, leucine, isoleucine, valine, threonine, phenylalanine; children also need histidine. These amino acids are not synthesized in the body and must be supplied with food in a certain ratio, i.e. balanced. Especially valuable are the essential amino acids tryptophan, lysine, methionine, contained mainly in animal products, the ratio of which in the diet should be 1:3:3.
Non-essential amino acids (arginine, cystine, tyrosine, alanine, serine, etc.) can be synthesized in the human body from other amino acids.
Vegetable products contain less proteins and they are mostly inferior, except for legumes (especially soy), which contain many complete proteins.
The daily intake of protein for people of working age is only 58-117 g, depending on gender, age and the nature of the person's work. Proteins of animal origin should be 55% of the daily requirement. In addition, when compiling a diet, the balance of the amino acid composition of food should be taken into account. The most favorable amino acid composition is presented in a combination of such products as bread and porridge with milk, meat pies, dumplings.
These are complex organic compounds consisting of glycerol and fatty acids, which contain carbon, hydrogen, oxygen. Fats are one of the main nutrients, they are an essential component in a balanced diet.
Fat is a part of cells and tissues as a plastic material, used by the body as an energy source (30% of the body's total energy needs). The energy value of 1 g of fat is 9 kcal. Fats supply the body with vitamins A and D, biologically active substances (phospholipids, tocopherols, sterols), give food juiciness, taste, increase its nutritional value, causing a person to feel full.
The rest of the incoming fat after covering the needs of the body is deposited in the subcutaneous tissue in the form of a subcutaneous fat layer and in the connective tissue surrounding the internal organs. Both subcutaneous and internal fat are the main reserve of energy (reserve fat) and are used by the body during strenuous physical work. The subcutaneous fat layer protects the body from cooling, and the internal fat protects the internal organs from shock, shock and displacement. With a lack of fat in the diet, a number of disorders of the central nervous system are observed, the body's defenses weaken, protein synthesis decreases, capillary permeability increases, growth slows down, etc.
Fatty acids are divided into saturated or saturated (i.e., saturated with hydrogen to the limit) and unsaturated or unsaturated.
Saturated fatty acids (stearic, palmitic, caproic, butyric, etc.) have low biological properties, are easily synthesized in the body, adversely affect fat metabolism, liver function, and contribute to the development of atherosclerosis, as they increase blood cholesterol.
Unsaturated fatty acids (oleic, linoleic, linolenic, arachidonic, etc.) are biologically active compounds capable of oxidation and addition of hydrogen and other substances. The most active of them are: linoleic, linolenic and arachidonic, called polyunsaturated fatty acids. According to their biological properties, they are classified as vital substances and are called vitamin F.
The biological value of fat also depends on the content of various fat-soluble vitamins A and D (fish fat, butter), vitamin E (vegetable oils) and fat-like substances: phosphatides and sterols.
Phosphatides are the most biologically active substances. These include lecithin, cephalin, etc. They affect the permeability of cell membranes, metabolism, hormone secretion, and blood coagulation. Phosphatides are found in meat, egg yolk, liver, dietary fats, and sour cream.
Sterols are a constituent of fats. In vegetable fats, they are presented in the form of beta-sterol, ergosterol, which affect the prevention of atherosclerosis.
In animal fats, sterols are contained in the form of cholesterol, which ensures the normal state of cells, participates in the formation of germ cells, bile acids, vitamin D3, etc.
Cholesterol is also formed in the human body. In normal cholesterol metabolism, the amount of cholesterol ingested and synthesized in the body is equal to the amount of cholesterol that breaks down and is excreted from the body.
3. Carbohydrates
These are organic compounds consisting of carbon, hydrogen and oxygen, synthesized in plants from carbon dioxide and water under the influence of solar energy.
Carbohydrates, having the ability to be oxidized, serve as the main source of energy used in the process of human muscle activity. The energy value of 1 g of carbohydrates is 4 kcal. They cover 58% of the body's total energy needs. In addition, carbohydrates are part of cells and tissues, are found in the blood and in the form of glycogen (animal starch) in the liver. There are few carbohydrates in the body (up to 1% of a person's body weight). Therefore, to cover energy costs, they must be supplied with food constantly.
In the case of a lack of carbohydrates in the diet during heavy physical exertion, energy is generated from the stored fat, and then the protein of the body. With an excess of carbohydrates in the diet, the fat reserve is replenished by converting carbohydrates into fat, which leads to an increase in human weight.
The source of carbohydrates supply to the body are vegetable products, in which they are presented in the form of monosaccharides, disaccharides and polysaccharides.
Monosaccharides are the simplest carbohydrates, sweet in taste, soluble in water. These include glucose, fructose and galactose.
Glucose is found in many fruits and berries (grapes) and is formed in the body during the breakdown of disaccharides and starch in food.
Fructose, having the same properties as glucose, is more favorable for the human body. It is three times sweeter than glucose and twice as sweet as sucrose, which allows you to consume less without reducing the level of sweetness of food. Fructose is found in honey, apples, pears, watermelon, currants, etc.
Galactose is not found in free form in food products; it is an integral part of milk sugar (lactose) and has a slightly pronounced sweet taste. Like fructose, it is beneficial for the body, does not increase blood sugar.
Disaccharides (sucrose, lactose and maltose) are carbohydrates, sweet in taste, soluble in water, split in the human body into two molecules of monosaccharides with the formation of sucrose - glucose and fructose, from lactose - glucose and galactose, from maltose - two molecules of glucose .
A person consumes sucrose (beet sugar) mainly in the form of sugar, in which it is 99.9%, in addition, it is found in beets, carrots, plums, apricots, bananas.
Lactose (milk sugar) enters the body with milk and dairy products, favorably affects the vital activity of lactic acid bacteria in the intestine, thereby suppressing the development of putrefactive microbes.
Maltose (malt sugar) is not found in natural foods. In the human body, during digestion, maltose is formed as an intermediate in the hydrolysis of starch to glucose.
Polysaccharides are complex carbohydrates consisting of many glucose molecules, insoluble in water, have an unsweetened taste. These include starch, glycogen, fiber.
Starch in the human body under the action of digestive juice enzymes is broken down to glucose, gradually satisfying the body's need for energy for a long period.
Glycogen enters the human body in small doses, since it is contained in small quantities in food of animal origin (liver, meat). During digestion, food glycogen is broken down into glucose. In the human body, glycogen is formed from glucose and accumulated in the liver as a reserve energy material.
Fiber in the human body is not digested due to the absence of the cellulase enzyme in the digestive juices, but, passing through the digestive organs, it stimulates intestinal motility, removes cholesterol from the body, creates conditions for the development of beneficial bacteria, thereby contributing to better digestion and assimilation of food.
Inulin in the human body during digestion is broken down to fructose, which does not increase blood sugar and quickly turns into glycogen. Contains inulin in Jerusalem artichoke, chicory root, which is recommended for patients with diabetes.
Pectin (carbohydrate-like) substances, getting into the human body with vegetables, fruits, stimulate the digestion process and contribute to the removal of harmful substances from the body. There are a lot of pectin substances in apples, plums, gooseberries, cranberries.
The daily intake of carbohydrates for the working-age population is only 257-586 g, depending on age, gender and nature of work. Easily digestible carbohydrates for people of mental labor and the elderly should be 15%, and for people of physical labor 20% of the daily carbohydrate intake; 75% of this norm is polysaccharides, mainly in the form of starch; 5% pectin and fiber.
4. Vitamins
These are low-molecular organic substances of various chemical nature, which act as biological regulators of vital processes in the human body.
Vitamins are involved in the normalization of metabolism, in the formation of enzymes, hormones, stimulate the growth, development, recovery of the body.
They are of great importance in the formation of bone tissue (vit. D), skin (vit. A), connective tissue (vit. C), in the development of the fetus (vit. E), in the process of hematopoiesis (vit. B12, Vd), etc. .d.
Some vitamins in the body are not synthesized and are not stored in the reserve, so they must be introduced with food (C, B, P). Part of the vitamins can be synthesized in the body (B2, B6, B9, PP, K).
Lack of vitamins in the diet causes a disease called beriberi. With insufficient intake of vitamins with food, hypovitaminosis occurs, which manifests itself in the form of irritability, insomnia, weakness, decreased ability to work and resistance to infectious diseases. Excessive consumption of vitamins A and D leads to a poisoning of the body, called hypervitaminosis.
Depending on the solubility, all vitamins are divided into: 1) water-soluble C, P, B, B2, B6, Vd, PP, etc.; 2) fat-soluble - A, D, E, K; 3) vitamin-like substances - U, F, B4 (choline), B.5 (pangamic acid), etc.
Vitamin C (ascorbic acid) plays an important role in the redox processes of the body, affects metabolism. The lack of this vitamin reduces the body's resistance to various diseases. Its absence leads to scurvy. The daily intake of vitamin C is 70-100 mg. It is found in all plant foods, especially in wild rose, blackcurrant, red pepper, parsley, dill.
Vitamin P (bioflavonoid) strengthens capillaries and reduces the permeability of blood vessels. It is found in the same foods as vitamin C. The daily intake is 35-50 mg.
5. Minerals
Mineral, or inorganic, substances are classified as indispensable, they are involved in vital processes in the human body: building bones, maintaining acid-base balance, blood composition, normalizing water-salt metabolism, and the activity of the nervous system.
Depending on the content in the body, minerals are divided into:
Macronutrients that are in significant quantities (99% of the total amount of minerals contained in the body): calcium, phosphorus, magnesium, iron, potassium, sodium, chlorine, sulfur.
Trace elements that are part of the human body in small doses: iodine, fluorine, copper, cobalt, manganese;
Ultramicroelements contained in the body in negligible amounts: gold, mercury, radium, etc.
Calcium is involved in the construction of bones, teeth, is necessary for the normal functioning of the nervous system, heart, and affects growth. Calcium salts are rich in dairy products, eggs, cabbage, beets.
Phosphorus is involved in the metabolism of proteins and fats, in the formation of bone tissue, and affects the central nervous system. Contained in dairy products, eggs, meat, fish, bread, legumes.
Magnesium affects the nervous, muscular and cardiac activity, has a vasodilating property. Contained in bread, cereals, legumes, nuts, cocoa powder.
Iron normalizes blood composition (included in hemoglobin) and is an active participant in oxidative processes in the body. Contained in the liver, kidneys, eggs, oatmeal and buckwheat, rye bread, apples. The daily requirement for iron is 0.018 g.
Potassium is involved in the water metabolism of the human body, increasing fluid excretion and improving heart function. Contained in dry fruits (dried apricots, apricots, prunes, raisins), peas, beans, potatoes, meat, fish.
Sodium, together with potassium, regulates water metabolism, retaining moisture in the body, and maintains normal osmotic pressure in tissues. There is little sodium in foods, so it is administered with table salt.
Chlorine is involved in the regulation of osmotic pressure in tissues and in the formation of hydrochloric acid (HC1) in the stomach. Chlorine comes with table salt.
Sulfur is part of some amino acids, vitamin Bp hormone insulin. Contained in peas, oatmeal, cheese, eggs, meat, fish.
Iodine is involved in the construction and functioning of the thyroid gland. Most of all iodine is concentrated in sea water, sea kale and sea fish.
Fluoride is involved in the formation of teeth and bones, and is found in drinking water.
Copper and cobalt are involved in hematopoiesis. Contained in small quantities in food of animal and vegetable origin.
To maintain the acid-base balance in the body, it is necessary to properly combine in the diet foods containing alkaline minerals (Ca, Mg, K, Na), which are rich in milk, vegetables, fruits, potatoes, and acidic action (P, S, C1) , which are found in meat, fish, eggs, bread, cereals.
Water plays an important role in the life of the human body. It is the most significant component of all cells (2/3 of the human body weight). Water is the medium in which cells exist and the connection between them is maintained, it is the basis of all fluids in the body (blood, lymph, digestive juices). With the participation of water, metabolism, thermoregulation and other biological processes take place.
Drinking water quality must meet the requirements of the current GOST "Drinking Water".
Water metabolism in the body is regulated by the central nervous system and is closely related to the mineral metabolism of potassium and sodium salts. With a large loss of water by the body through sweat or increased consumption of salt, the osmotic pressure of the blood plasma changes, which entails excitation in the cerebral cortex, resulting in a feeling of true thirst that regulates human water consumption. False thirst due to dry mouth, unlike true thirst, does not require water to enter the body. To remove this sensation, it is enough to increase salivation with an acidic product or moisten your mouth with water.
Questions for self-control
1. The value of nutrients.
2. Proteins. Their role in the human body.
3. Fats. Their role in the human body.
4. Carbohydrates. Their role in the human body.
5. Vitamins. Their role in the human body.
6. Fat-soluble vitamins.
7. Water-soluble vitamins.
8. Minerals. Their role in the human body.
9. Water. Its role in the human body.
Food is one of the most important environmental factors. The normal functioning of the human body depends on it. Food is necessary for a person to build and restore the cells and tissues that make up the body, to cover the energy costs associated with physical and mental work, and to maintain a constant human body temperature.
For normal human life, it is necessary that as a result of nutrition he receives all the necessary substances. The composition of the human body includes (on average): 66% water, 16% proteins, 12.4% fats, 0.6% carbohydrates, 5% mineral salts, as well as vitamins and other substances.
Water is an integral part of all tissues of the human body. It serves as an environment in which the body's metabolic processes take place, and also plays an important role in the body's thermoregulation. The amount of water allocated and consumed by a person (per day) varies significantly and depends on the ambient temperature, the work performed and other factors.
The average daily human need for water is 2-2.5 liters; this need is covered with food (about 1 l), moisture (1-2 l), and also as a result of oxidative processes in the body, accompanied by the release of water (about 0.3 l).
Squirrels are the most important component of the cells and tissues of the body and the main plastic material from which the human body is built. Unlike plants capable of synthesizing protein substances from inorganic substances of the soil and air, animal organisms need ready-made plant and animal proteins that come with food. Therefore, proteins are an essential part of human nutrition.
Proteins are made up of amino acids, of which there are up to 20. The proteins contained in various foods do not have the same amino acid composition. Amino acids are divided into nonessential and irreplaceable, or vital. Non-essential amino acids can be formed by the body in the process of metabolism, while essential amino acids are not formed in the body and must be supplied with food in finished form. The essential amino acids include arginine, valine, histidine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, phenylalanine. The absence of these amino acids in food leads to stunting of the body, impaired blood formation and other changes in the body.
Proteins that contain all the essential amino acids are called complete proteins. These proteins include most proteins of animal origin (milk, meat, eggs, etc.). Many proteins of plant origin belong to inferior ones. The combination of animal and vegetable proteins allows you to get food that best meets the needs of the body in protein. Therefore, a varied diet can satisfy a person's need for all the amino acids he needs. It is believed that the daily human diet should include approximately 60% of animal proteins and 40% of vegetable proteins.
Fats are part of the cells and tissues of the body, some of them, together with proteins, act as the building material of the animal body. The other part is deposited in it as a reserve and is used as an energy source. Fats are required for the normal functioning of the nervous system, improve the taste of food, promote the absorption of fat-soluble vitamins, some of them (butter, unrefined vegetable) contain vitamins.
The nutritional value and assimilation by the body of various fats are not the same. To a large extent, the use of fats by the body depends on the quantity and quality of the fatty acids of which they are composed. Solid fats are made up primarily of saturated fatty acids, while liquid fats are made up of unsaturated fatty acids. Fats. having a melting point below the temperature of the human body (vegetable oils, cow butter), are absorbed by the body better than fats with a melting point above the temperature of the human body (mutton fat).
An important role in the body is played by fat-like substances - lecithin and cholesterol. Both substances play an important role in the body's metabolic processes and have opposite biological effects. Phosphorus is a part of lecithin. It is involved in the absorption of fats, is part of the nervous tissue, cell nuclei, and ensures the normal exchange of cholesterol in the body. Cholesterol is synthesized in significant quantities in the body and only about 20% of it comes from food. It is involved in complex, vital metabolic processes.
Carbohydrates are the most widely used nutrients. Their content in food averages up to 70%, they are the main source of energy. According to their structure, carbohydrates are divided into monosaccharides (glucose, fructose, galactose), disaccharides (beet sugar, lactose), polysaccharides (starch, glycogen, fiber).
Monosaccharides are most fully absorbed by the body. Sugar and starch are digested somewhat more slowly. Fiber is practically not absorbed by the body, but plays a positive role in digestion, contributing to intestinal motility.
The main source of carbohydrates are products of plant origin - sugar, cereals, bread, potatoes.
mineral salts necessary for the human body to maintain the osmotic pressure of fluids, metabolism, building the skeleton and teeth, activating enzymes, etc. Calcium and phosphorus are the main components of bones. Phosphorus is also involved in the formation of nervous tissue. Both of these elements are found in milk and dairy products.
Of great importance in the metabolism of the body and in maintaining the osmotic pressure of tissues are potassium, contained in vegetables, fruits, dry fruits, and sodium, supplied with table salt. Magnesium activates phosphorus metabolism, it enters the body with bread, vegetables, fruits. Iron is involved in the oxygen supply of tissues. It is found in liver, meat, egg yolk, tomatoes.
Copper, nickel, cobalt, chlorine, iodine and many other elements are also necessary for the normal functioning of the body.
vitamins- organic substances of various chemical composition. They are essential for normal metabolism in the body. The lack of one or another vitamin in food leads to diseases. Diseases resulting from a prolonged lack of vitamins in food are called beriberi. They are rare. More often there are hypovitaminosis associated with a lack of vitamins in food.
Vitamins are divided into fat-soluble and water-soluble. Water-soluble vitamins include vitamins B 1, B 2. B 6 , B 12 , C, PP, folic, pantothenic and para-aminobenzoic acids, choline, etc., to fat-soluble vitamins - vitamins A, D, E, K, etc.
A varied diet with the inclusion in the diet of natural products in the form of vegetables, fruits, berries, milk, eggs, vegetable oil usually provides a healthy person's need for vitamins.
