about the project
News of medicine
Licensed books on medicine
<< Previous Next >>

Food and basic food substances

The most important condition for nutrition is the correct combination of all nutrients in the daily diet of man, and they must be introduced in quantities that completely cover all the waste of the body in both quantitative and qualitative terms.
In the human body, oxidation processes (compounds with oxygen) of various food substances - proteins, fats, carbohydrates, which are accompanied by the formation and release of heat - are continuously occurring. This heat is necessary for all life processes, it is spent on heating the inhaled air, on maintaining the body temperature. Thermal energy also provides the activity of the muscular system. The more muscle movements a person performs, the more he produces losses, which require more food to cover.
The need for more food is expressed in thermal units - calories. At present, according to the international measurement system (SI), the energy value of food is expressed in joules (1 kcal = 4,184 kJ). Caloric content of food is the amount of energy that is formed in the body as a result of the assimilation of food. Calorie is the amount of heat needed to heat 1 liter (large calorie) and 1 mL (low calorie) of water at 15 degrees Celsius, one degree. Each gram of protein and every gram of carbohydrates of any food when burned in the body (during oxidation) generates heat, equal in quantity to 4 kcal, and when burning 1 g of fat, 9 kcal is formed. Knowing the value

energy needs can determine the needs for basic nutrients - proteins, fats and carbohydrates. Minerals, vitamins and water are also important for the life of the body.
Proteins are of particular importance in nutrition. With their action, the main manifestations of life are connected: metabolism, muscle contraction,
irritability of nerves, ability to grow and multiply, and even thinking. They are contained in all tissues and fluids of the body, being their main component. Proteins consist of a variety of amino acids that determine their biological significance. Some of the amino acids are formed in the body itself. They are called interchangeable amino acids. Others enter the body only with food. These amino acids are called essential amino acids. For the physiologically valuable life of the organism, it is necessary to have all essential amino acids in food. Insufficient food content in at least one essential amino acid leads to a decrease in the biological value of proteins and may cause protein deficiency, despite the sufficient amount of protein in the diet. Irreplaceable amino acids are found mainly in products of animal origin: in milk, cottage cheese, meat, fish, eggs.
However, the human body can not do without proteins of vegetable origin, which are contained in bread, cereals and vegetables, which mainly include interchangeable amino acids. Proteins of animal products in combination with proteins of plant origin provide the body with substances necessary for its development and life.
The body of an adult person on average needs to get about 1-1.2 g of protein per 1 kg of body weight with food. This means that a person weighing 70-75 kg should receive from 70 to 90 grams of protein per day.
If the intensity of physical labor increases, the needs of the organism in the protein also increase. The average daily protein norm of an adult is considered to be 90-100 g per day, 55% of it should be provided by an animal protein.
The most important sources of protein are meat, fish, eggs, cheese, milk, bread, potatoes, beans, soy, peas.
Proteins in nutrition can not be replaced by any other substances.
The physiological significance of fats is very diverse. They are a source of energy and surpass the energy of all other substances. Fats participate in the recovery processes, being a structural part of cells and their membrane systems; serve as solvents of vitamins A, E, D and promote their assimilation. Improving the taste of food, fats increase its nutritional value. In addition, they contribute to the development of immunity and help the body to keep warm.
Inadequate intake of fat in the body can lead to a violation of the central nervous system, changes in the skin, kidneys, organs of vision, etc. Animals that received a fat-free diet showed less endurance and longevity.
In the composition of fat and its accompanying substances, vital nutrients such as polyunsaturated fatty acids, lecithin, vitamins A, E, etc. have been identified.
The average need of an adult in fat is 80-100 g per day, including vegetable - 25-30 g.
In food, due to fat, 33% of the daily energy value of the diet should be provided, which according to modern data is optimal. At 1000 kcal, 37 grams of fat is needed.
Fats in sufficient quantity are contained in such food products as brains, heart, eggs, liver, butter, cheese, meat, lard, poultry, fish, milk. Valuables are also valuable, especially in the nutrition of older people, since they do not contain cholesterol.
Carbohydrates are the main source of energy. On average, they account for 50 to 70% of the daily caloric intake. Each gram of carbohydrates provides 4 kcal of energy. The need for carbohydrates depends on the energy expenditure of the body.
In people engaged in mental or easy physical labor, the daily requirement ranges from 300 to 500 g. For those engaged in manual labor and athletes, it is much higher. Inclined to fullness, it is possible to reduce the amount of carbohydrates in food rations without compromising on health.
The most rich in carbohydrates are plant products - bread, cereals, pasta, potatoes. A pure carbohydrate is sugar.
Excess amount of carbohydrates breaks the correct ratio of the main parts of food, which, in turn, leads to a metabolic disorder.
Vitamins are substances that do not supply the body with energy, but are absolutely necessary in minimum quantities to sustain life.
They are irreplaceable, because they are not synthesized or almost not synthesized, not produced by the cells of the body. Vitamins come either with food in which they are contained, or in the form of synthetic drugs. They regulate, direct and accelerate the processes of metabolism.
Vitamins are divided into two large groups: water-soluble and fat-soluble.
The group of fat-soluble vitamins include vitamins A, D, E, K.
Vitamin A has an effect on the growth of the body, on its resistance to infections. It is necessary to maintain normal vision, skin and mucous membranes. Contains vitamin A in large quantities in fish oil, cream, butter, egg yolk, liver. In some plant products: carrots, lettuce, spinach, tomatoes, green peas, apricots, oranges - contains carotene - provitamin A, which in the body turns into vitamin A.
Vitamin D promotes the formation of bone tissue and stimulates the growth of the body. If there is a lack of vitamin D in the food, the normal absorption by the body of calcium and phosphorus is violated, which leads to the appearance of rickets. The greatest amount of vitamin D is found in fish oil, egg yolk, liver, fish eggs. In milk and butter, vitamin D is contained in a small amount.

Vitamin K is involved in tissue respiration, contributes to the maintenance of normal blood clotting. This vitamin is synthesized in the body by intestinal bacteria. Lack of it can occur with diseases of the digestive system or when taking various antibacterial drugs. Vitamin K is found mainly in tomatoes, in green parts of plants, spinach, cabbage, nettles.
The group of water-soluble vitamins include vitamin C and B vitamins.
Vitamin C, or ascorbic acid, actively participates in oxidation-reduction processes, affects carbohydrate and protein metabolism, increases the body's resistance to various infections. This vitamin is found in many fresh vegetables and fruits. The most rich are the fruits of dog rose, black currant, chokeberry, sea-buckthorn, gooseberries, citrus, cabbage, potatoes, leafy vegetables.
The group of vitamins B consists of 15 active, water-soluble, independent vitamins, which take part in the processes of metabolism in the body, the process of hematopoiesis, and also plays an important role in carbohydrate, fat and water metabolism. B vitamins are growth stimulants. Vitamins of this group are found in beer and baker's yeast, buckwheat and oatmeal, rye bread, milk, meat, liver, egg yolk, green part of plants.
Vitamin E (tocopherol) refers to fat-soluble vitamins. It affects the activity of the endocrine glands, the exchange of proteins, carbohydrates, provides intracellular metabolism. Vitamin E has a beneficial effect on the course of pregnancy and fetal development. Most of this vitamin is found in corn kernels, in carrots, cabbage, green peas, eggs, meat and fish products, in cow and olive oil.
Prolonged absence of vitamins in the diet leads to avitaminosis. But more often there are hypovitaminosis, the development of which is associated with a lack of vitamins in food; this is especially observed in the spring and winter months. With hypovitaminosis, fatigue increases, weakness, apathy, decreased efficiency, the resistance of the organism decreases.
Between the action of individual vitamins there is a close relationship. The lack of food in one of the vitamins causes a violation of the exchange of other substances; only with proper nutrition vitamins have the proper effect.
In the food must necessarily contain mineral substances that are part of the cells and tissues of the body and participate in a variety of metabolic processes. The main mineral substances that are necessary for the sick and healthy include calcium, potassium, magnesium, phosphorus, chlorine, sodium salts are macro-elements, they are needed daily in relatively large quantities, as well as iron, zinc, manganese, chrome, iodine, fluorine , which are necessary in very small quantities, so they are called trace elements. Microelements enter the human body with products of animal and vegetable origin. So, for example, iodine is rich in sea products; zinc is most rich in cereals, yeast, legumes, liver; Copper and cobalt are found in beef liver, kidney, egg yolk, honey.
The mineral composition of berries and fruits is very diverse. They contain a lot of potassium, iron, copper, phosphorus. And all these mineral substances are perfectly absorbed. In addition, they are low-calorie, they lack fat and cholesterol, a lot of vitamin C - all this makes them indispensable in the diet suffering from many diseases: hypertension, circulatory disorders, kidney damage, especially with the formation of edema. Potassium contained in these products, increases the release of fluid from the body.
Good digestion of food by the body depends on its skillful preparation, appearance, variety of menus. It is very important how the food looks, whether the table is beautifully laid. From one pleasant type of dish, gastric juice begins to be actively allocated, and the entire digestive system is prepared by the time of meal.
You can not eat very hot and very cold food. The temperature of hot dishes should not be more than 60 degrees, cold - not lower than 10 degrees.
In certain diseases, for example, with diabetes, food should contain not only certain foods, but the entire daily diet should have the established chemical composition. It is necessary to observe a certain menu, each dish of which is prepared according to the stipulated norms and with the appropriate culinary processing.
Health food at home has its own characteristics, because you have to take into account that the patient's appetite is usually lowered, and the list of products in his menu is limited, and seasonings are prohibited. Nevertheless, the dishes of dietary cuisine can be very tasty, if they are cooked with knowledge of the matter.
<< Previous Next >>
= Skip to the content of the tutorial =

Food and basic food substances

  1. Food and basic food substances
    The most important condition for nutrition is the correct combination of all nutrients in the daily diet of man, and they must be introduced in quantities that completely cover all the waste of the body in both quantitative and qualitative terms. In the human body, there are continuous processes of oxidation (compounds with oxygen) of various food substances - proteins, fats, carbohydrates, which
  2. Food and basic food substances
    The most important condition for nutrition is the correct combination of all nutrients in the daily diet of man, and they must be introduced in quantities that completely cover all the waste of the body in both quantitative and qualitative terms. In the human body, there are continuous processes of oxidation (compounds with oxygen) of various food substances - proteins, fats, carbohydrates, which
  3. Food and basic food substances
    The most important condition for nutrition is the correct combination of all nutrients in the human diets. These substances can be divided into six groups: 1) proteins, 2) fats, 3) carbohydrates, 4) vitamins, 5) mineral substances, 6) water. They must be introduced in quantities that completely cover all the waste of the body in both quantitative and qualitative terms. In the human body continuously
  4. Food and biological value of basic foodstuffs
    The nutritional value of the product is determined by the content of nutrients (food and flavor) in it, its biological value is its amino acid content, the presence of PUFA, vitamins, mineral salts and other biologically active substances. The main food products are bread, meat and meat products, fish and fish products, milk and dairy products, vegetables, berries, fruits and some others.
  5. The concept of hygienically nutrition. Nutrition standards Food products, their composition and energy value.
    Nutrition is a complex process of ingestion, digestion, absorption and absorption in the body of nutrients necessary to cover its energy expenditure, the construction and renewal of cells and tissues of the body, the regulation of the physiological functions of the body. In hygiene, the term "nutrition" is used, meaning a diet built on scientific principles that can fully meet the need for
    Each country, as the basis of its guidelines for feeding and feeding children, should use the values ​​of nutrient intake recommended for infants and young children, based on scientific data received by the international scientific community. INTRODUCTION This and the four following chapters discuss and compare the recommended values
  7. Carcinogenic chemicals in food
    One of the oldest medical problems is "Nutrition and Cancer". This is due to the fact that the food can contain carcinogenic chemicals (KChV) and their predecessors. First of all, waste from industrial enterprises, thermal power stations, heating systems and transport belong to the sources of KHV. Migrating in the atmosphere, in the soil and water bodies, these carcinogens can get into food products. Of such
  8. Nutritional substances and their importance.
    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, the maintenance of heat and the implementation of all life processes, including physical and mental work. 1.Belki This is a complex organic compound from
  9. Nomenclature of recommended values ​​of consumption of nutrients
    Several countries have adopted their own PRTR systems and use different term education systems (Table 8). The European Union uses population reference consumption values ​​(HDPE), and in the former Soviet Union the term "physiological norms" of the RVP used in this publication is consistent with the reference values ​​of nutrient intake shown in
  10. Effect on the body of purified food substances
    Throughout evolution, the animal's body consumed only natural food, which, with very few exceptions, consisted of complexes of various substances. Therefore, it is not surprising that the mechanisms of the metabolism formed in phylogeny suggest, on the one hand, the supply of food substance in a natural form created by nature (and not separately proteins, carbohydrates, fats, iron,
  11. Hygienic regulation of harmful substances in the environment and food products
    Hygienic regulation is mandatory for all toxic substances entering the human body from the environment - air, water, soil, food products, materials in contact with food, etc. Any chemical substance is toxic under certain conditions of exposure. Toxicity is the ability of a substance to harm a living organism. On the human body
  12. Food poisoning caused by chemical impurities
    This group of non-microbial food poisoning includes poisoning caused by pesticides, nitrites and other food additives, with their increased content in products, impurities that have passed into products from equipment, implements, packaging, packaging films, etc. Poisoning with nitrites and other food additives with increased content in products Poisoning with nitrites. With constant
  13. Pollution of food by foreign chemicals
    Alien chemicals (CHVV) are also called xenobiotics (from Greek henos - alien). They include compounds that, by their nature and quantity, are not inherent in a natural product, but can be added to improve technology, preserve or improve the quality of the product, or they can form in the product as a result of processing and storage, and
Medical portal "MedguideBook" © 2014-2016