Fats refer to substances that perform in the body, mainly an energy function. Fats are superior to all other food components (carbohydrates and proteins), since when they are burned, 2 times more energy is released.

Fats are involved in plastic processes, being a structural part of cells and their membrane systems. Inadequate intake of fat in the body can lead to disruption of the central nervous system due to disruption of the flow of nerve signals. In this case, a weakening of immunological mechanisms occurs.

A deficiency of fats leads to changes in the skin, where they perform a protective role, protecting the skin from hypothermia, increase the elasticity of the skin and prevent it from drying out and cracking; as well as dysfunction of internal organs, in particular the kidneys, which fats protect from mechanical damage.

A number of biologically valuable substances enter the body only together with food fats: fat-soluble vitamins, phosphatides (lecithin), polyunsaturated fatty acids (PUFA), sterols, tocopherols and other substances with biological activity.

Edible fats
Edible fats are composed of esters of glycerol and higher fatty acids.

The most important component that determines the properties of fats are fatty acids, which are divided into saturated (marginal) and unsaturated (unsaturated).

The most important are butyric, stearic, palmitic saturated acids, which constitute up to 50% of fatty acids of lamb and beef fat, causing a high melting point of these fats and their poor digestibility.

Of the unsaturated fatty acids, the most important are: linoleic acid, linolenic, arachidonic acids. They are collectively known as "vitamin-like factor F". The first two are widespread in liquid fats (oils) and in the fat of marine fish. Vegetable oils - sunflower, corn, olive, linseed - contain up to 80 - 90% of the total amount of fatty acids.

The biological role of dietary unsaturated fatty acids in human nutrition
1. Participate as structural elements of cell membranes.
2. Are a part of connective tissue and nerve fiber sheaths.
3. Affect the metabolism of cholesterol, stimulating its oxidation and excretion from the body, as well as forming esters with it, which do not fall out of solution.
4. Have a normalizing effect on the walls of blood vessels, increasing their elasticity and strengthening them.
5. Participate in the exchange of B vitamins (pyridoxine and mmin).
6. Stimulate the body's defense mechanisms (increase resistance to infectious diseases and radiation).
7. Possess lipotropic action, i. E. prevent fatty liver.
8. Are important in the prevention and treatment of diseases of the cardiovascular system.

The requirement for food unsaturated fatty acids is 3-6 g / day.
According to the content of PUFA, edible fats are divided into three groups:
Group 1-rich in them: fish oil (30% arach.), Vegetable oils.
Group 2: with an average content of PUFA - lard, goose, chicken fat.
Group 3 - PUFAs do not exceed 5 - 6%: mutton and beef fats, some types of margarine.

The biological role of phosphatides
The fat contains phosphatides. The greatest biological activity is possessed by: lecithin, cephalin, sphingomyelin:
1) in combination with proteins, they are part of the nervous system, liver, heart muscle, gonads;
2) participate in the construction of cell membranes;
3) participate in the active transport of complex substances and individual ions into and out of cells;
4) participate in the process of blood coagulation;
5) promote better use of protein and fat in tissues;
6) prevent fatty liver infiltration;
7) play a role in the prevention of atherosclerosis - prevent the accumulation of cholesterol in the walls of blood vessels, contributing to g 111 cleavage and excretion from the body.

The need for phosphatides is 5-10 g / day.

The biological role of sterols
The fat contains sterols, water-insoluble compounds. There are phytosterols - of plant origin and zoosterols - of animal origin.

Phytosterols have biological activity in the normalization of fat and cholesterol metabolism, prevent the absorption of cholesterol in the intestine, which is of great importance in the prevention of atherosclerosis. They are found in vegetable oils.

Cholesterol is an important zoosterol. It enters the body with animal products, but it can also be synthesized from intermediate metabolic products of carbohydrates and fats.

Cholesterol plays an important physiological role as a structural component of cells. It is a source of bile acid hormones (sex hormones) and the adrenal cortex, a precursor of vitamin D.

At the same time, cholesterol is also considered as a factor in the formation and development of atherosclerosis.

In bile, cholesterol is retained in the form of a colloidal solution due to binding to phosphatides, unsaturated fatty acids, proteins.

In case of metabolic disorders or lack of them, cholesterol falls out in the form of small crystals that settle on the walls of blood vessels, in the biliary tract, which contributes to the appearance of atherosclerotic plaques in the vessels, the formation of gallstones.

The need for cholesterol is 0.5 - 1 g / day. Cholesterol is contained in almost all products of animal origin: in the brain - 2000 mg%, paste "Ocean" - 1000 mg%, chicken and duck eggs - 570 - 560 mg%, hard cheeses - 520 mg%.

Animal fats are sources of vitamins A, D, E, F.

Excessive consumption of fats, especially of animal origin, leads to the development of atherosclerosis, impaired fat metabolism, liver function, and an increase in the frequency of malignant neoplasms.

Insufficient intake of fat into the body can lead to a number of disorders of the central nervous system, weakening of immunobiological mechanisms, pathological changes in the skin, kidneys, organs of vision,

With a fat-free diet, animals stop growing, their body weight decreases, sexual function and water exchange are impaired, the body's resistance to unfavorable factors is weakened, and life expectancy is shortened.

However, for many diseases it is necessary to limit the amount of fat:
- with obesity;
- with diseases of the pancreas;
- with chronic colitis;
- with liver diseases;
- with diabetes;
- with acidosis.

Fats belong to substances that perform mainly an energy function in the body, since when they are burned, 2 times more energy is released (1 g of fat forms 9.3 kcal, while 1 g of protein and the corresponding amount of carbohydrates are only 4.3 kcal ).

Fats are involved in plastic functions, being a structural part of cells and their membrane systems. Lack of accurate fat intake can lead to:

Violation of the central nervous system due to a violation of the direction of the streams of nerve signals;

Weakening of immunological mechanisms;

Skin changes, where they play a protective role, protecting against hypothermia, increasing elasticity and preventing drying and cracking;

Violation of internal organs, in particular the kidneys, which protect against mechanical damage.

Fat improves the palatability of food and increases its nutritional value. Only together with fats does food enter the body: fat-soluble vitamins, phosphatides (lecithin), polyunsaturated fatty acids, sterols, tocopherols, etc.

In the human body, fat is in two forms: structural (protoplasmic) and reserve (in fat depots).

The amount of protoplasmic fat is maintained in organs and tissues at a constant level and does not change even during fasting.

The degree of accumulation of reserve fat depends on the nature of the diet, the level of energy expenditure, age, sex, and the activity of the endocrine glands.

Hard physical work, some diseases, insufficient nutrition contribute to a decrease in the amount of stored fat. And, conversely, excess nutrition, physical inactivity, decreased function of the gonads, thyroid gland lead to an increase in reserve fat.

EDIBLE FATS - from esters of glycerol and higher fatty acids.

The most important component that determines the properties of fats are fatty acids. They are divided into saturated (marginal) and unsaturated (unsaturated). Saturated acids (butyric, stearic, palmitic), which are found in animal fat and account for up to 50% of fatty acids of lamb and beef fat, are of the greatest importance in terms of the degree of distribution in food products and their properties, causing a high melting point and worse digestibility.

Of the unsaturated fatty acids, the most important are linoleic, linolenic and arachidonic, known collectively as "vitamin-like factor F". The first two are widespread in liquid fats (oils) and in the fat of marine fish. Vegetable oils (sunflower, corn, olive, flaxseed) contain up to 80-90% of the total amount of fatty acids.

Of great importance is PUFA-that arachidonic, which is found in small amounts in some animal fats, but it is absent in vegetable oils. So, pork fat contains 500 mg% arachidonic acid, 5 times more than beef and mutton fat, and saturated acids in it are 20% less.

Thus, the nutritional and biological properties of pork fat are higher than that of beef and lamb.

An indicator of the biological value of fats is also the presence of vitamins A, D, E. Therefore, butter containing these vitamins, despite the low level of PUFA, is a product of high biological value.

II... The biological role of phosphatides. ( lecithin, cephalin, sphingomyelin.)

In combination with proteins, they are part of the nervous tissue, liver, heart muscle, gonads.

Participate in the construction of cell membranes, determine the degree of their permeability to fat-soluble substances.

Participate in the active transport of complex substances and individual ions into and out of cells.

Phospholipids are involved in blood clotting.

Promotes better utilization of protein and fat in tissues.

Prevents fatty liver infiltration.

They play a role in the prevention of atherosclerosis - they prevent the accumulation of olesterol in the walls of blood vessels, promote its breakdown and excretion from the body.

Due to these properties, phosphatides are classified as lipotropic factors.

(65) is contained in squirrels treski, eggs, meat, i.e. In the proteins of animal products.

In nature, the highest content of sulfur-containing amino acids (methionine + cystine) beanssunflower.

2. Lysine- closely related to bloodcreation. With a deficiency, the number of erythrocytes and the amount of HB decreases.

With its lack, there is a violation of bone calcification, muscle wasting. Lysine is essential for the growth of young organisms. The main source - milkny protein. Curd contains 1.5% of it. There isalso in animal meat.

3. Tryptophan is an amino acid necessary for the synthesis of nicotinic acid, hemoglobin in the body, the formation of whey proteins, a growth factor. The younger the age, the higher the need for tryptophan (1.0).

But tryptophan is difficult to get enough. 100 g of meat, eggs contain only 0.2 g.

In milk, tryptophan is found in albumin, which, when heated above 70 ° C, denatures and precipitates on the walls of the dishes, therefore, tryptophan is also lost. It is best to consume raw milk from a healthy cow.

Foods - sources of complete protein (%)

Meat - 16-22 fish - 14-20

poultry - 6-24 eggs - 12.5

egg powder - 52 milk - 3.4

lean cottage cheese - 17.5 fat cottage cheese - 13

different cheeses - 18-25

Proteins from plant products are less complete in terms of amino acid composition.

But the inadequacy of the amino acid composition of plant proteins is compensated for when eating mixed food and especially due to the rational selection of various products of plant and animal origin.

In addition, among plant foods, there are legumes that contain a large amount of complete proteins:

Peas - 19.8%

Beans - 19.6%

Lentils - 20.4%

pea flour - 22%

5) fat-free soy flour - 41.4%

The proteins of these products have a sufficient amount of especially valuable amino acids, such as tryptophan, lysine, methionine, and soy contains even more of these amino acids than meat, and it contains the same amount of methionine as in cottage cheese.

(66) The need for phosphatides is 5-10 g / dayki.

Of plant products, unrefined oils are mainly characterized by a significant content.

Soy lecithin is used abroad as a source of phosphatides.

In our country, phosphatide concentrates are produced - sunflower and soybean ones, used for refined vegetable oils and margarine. An obstacle to the use of these concentrates is their unsatisfactory taste properties, rapid oxidation and rancidity.

A balanced ratio of proteins, fats, carbohydrates coming with food is the key to proper nutrition and the formation of a healthy, beautiful body.

Fats are arguably the most questionable. For many, their very name is associated with something unhealthy. However, not all of them are harmful, moreover, without certain types of fats, an active sports lifestyle will lead to depletion of the body. The attitude towards them is most often negative, but how reasonably can fats be considered harmful to the body and its functioning?

What are fats and their varieties - harmful and useful

Fats are naturally complex organic compounds. From a chemical point of view, these are esters of a trihydric alcohol of glycerol and carboxylic acids. From the point of view of ordinary people, fats are complex chemicals with a large molecule that, when broken down, releases a huge amount of energy. However, in order to effectively release energy with fats, the body must be saturated not only with them, but also with carbohydrates and oxygen.

Today the following classification of natural fats is adopted:

• Saturated or animals. These are the so-called harmful fats, an excess of which leads to various complications from the heart, blood vessels, and liver.
• Unsaturated or vegetable fats are trivially called "healthy" fats. They, in turn, are divided into mono- and polyunsaturated. Monounsaturated fats have a small molecule, so they break down more easily than others into their constituents - water and carbon dioxide, while releasing almost twice as much energy as the same amount of carbohydrates. Polyunsaturated fats are broken down somewhat more difficult, but they are practically the only source of essential acids for the body. In addition, they are resistant to heat treatment.

The value of fats for the body

The beneficial functions of fats in the body are as follows:

• When fat is broken down, a large amount of energy is released.
• Participate in the life of epithelial cells.
• They are a building material for human brain cells.
• Some vitamins, getting into the human body, are not absorbed by them without fats.
• They are sources of essential acids.

Adult Fat Intake Rates

The average rate of fat consumption by an adult is calculated based on the ratio of 1 g of fat per 1 kg of body weight, that is, the approximate rate of their consumption per day for men is 80-100 g, for women 50-60 g. At least 80% of this quantities should be vegetable fats. Moreover, the share of unsaturated mono compounds should account for more than half of the total daily intake of healthy fats.

Fat intake from sports and unhealthy unnatural fats

Sports enthusiasts should increase the vegetable fat content of their diet to 90% of the daily fat intake. The remaining 10% should be animal fats.

In addition to the classification of natural fats described above, there are two more types of harmful fats, the appearance of which is due to the development of society. These are oxidized (transgenic) fats and trans fatty acids. It is an integral part of fast food and high-calorie sweets:

• deep-fried dishes;
• shortbread cookies, biscuits, creams;
• sauces including ketchup and mayonnaise.

Any person should limit the use of these "goodies", because the price for love to them is too high: heart disease, obesity, diabetes mellitus, oncology. Athletes should avoid using these products altogether, as they add unnecessary stress to the body when combined with training.

Fats in foods

Vegetable fats:

• Monounsaturated fats (Omega-9) lower total bad cholesterol levels. They contain olive, peanut, hazelnut, sesame oil, avocado, pistachio, hazelnut, cashew, sesame, olives.
• Polyunsaturated fats. A source of healthy Omega-3s for the cardiovascular system is oily sea fish, shrimp, oysters, lake trout, flaxseed and oil, hemp seed and oil, pine nuts and walnuts. Omega-6s are found in corn, sunflower, soy, oils, and seeds.

Sources of animal fats:

• Butter and milk fats.
• Animal fats such as beef tallow, lard.
• Palm oil.

Animal fats contain "bad" cholesterol, and the liver suffers from excessive consumption. Such fats are difficult to digest, creating a great burden on the body. Milk fats load the body less, if it is difficult to do with only vegetable fats, you can use a small amount of butter. Just remember that it cannot be stored and heated for a long time! All animal fats are not suitable for cooking!

Fat and weight loss

Fats are high in calories, but you can't completely stop eating them. With a deficiency of fats, first of all, brain cells will begin to suffer and the appearance of the skin will deteriorate.

You should choose the right fat strategy:

• Reduce their intake to a physiological minimum.
• When planning your meals, remember that fats are an essential part of many other foods.
• Eat only vegetable fats.
• Purchase only virgin oils.

A competent diet is the first step towards a healthy body and a beautiful figure. Remember that the human body is a complex mechanism in which everything is interconnected. The intake of proteins, fats, carbohydrates with food is necessary for them to perform their functions useful for the body. However, an excess or deficiency of each element can lead to the development of serious complications, especially for people who have regular physical activity. A balanced and healthy diet for you!

Fats (lipids) are a group of complex organic compounds, which include triglycerides and lipoid substances (phospholipids,).

Triglycerides are ester compounds of glycerol and fatty acids.

In the gastrointestinal tract of a healthy person, at a normal level of fat intake, approximately 95% of their total amount is absorbed.

Among foods that are sources of fats, they are presented in the form of fatty products (oil, lard, etc.) and the so-called hidden fats, which are found in many foods.

Foods containing hidden fats are the main suppliers of dietary fats to the human body.

The fatty acids that make up dietary fats are divided into three large groups: saturated, monounsaturated, and polyunsaturated.

Essential fatty acids of food and their physiological significance

* HDL - high density lipoproteins.

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“Chemistry is everywhere, chemistry is everywhere:

In everything we breathe

In everything we eat. "

In everything we wear

People have long learned to isolate fat from natural objects and use it in everyday life. Fat burned in primitive lamps, illuminating the caves of primitive people, grease was used to lubricate the runners along which ships were launched. Fat is the main source of our food. But improper diet, a sedentary lifestyle leads to excess weight. Desert animals store fat as a source of energy and water. The thick fat layer of seals and whales helps them swim in the cold waters of the Arctic Ocean.

Fats are widespread in nature. Along with carbohydrates and proteins, they are part of all animals and plant organisms and constitute one of the main parts of our food. Sources of fats are living organisms. Among animals, these are cows, pigs, sheep, chickens, seals, whales, geese, fish (sharks, cod, herring). From the liver of cod and shark fish oil is obtained - a medicine, from herring - fats used to feed farm animals. Vegetable fats are most often liquid, they are called oils. Fats of such plants as cotton, flax, soybeans, peanuts, sesame seeds, rapeseed, sunflower, mustard, corn, poppy, hemp, coconut, sea buckthorn, rose hips, oil palm and many others are used.

Many animals and humans use fat as an insulating shell, for example, in some marine animals, the thickness of the fat layer reaches a meter. In addition, in the body, fats are solvents of flavorings and dyes. Many vitamins, such as vitamin A, dissolve only in fats.

Some animals (most commonly waterfowl) use fats to lubricate their own muscle fibers.

Fats increase the satiety effect of food, as they are digested very slowly and delay the onset of hunger.

History of the discovery of fats

Back in the 17th century. German scientist, one of the first analytical chemists Otto Taheny(1652-1699) first suggested that fats contain "hidden acid".

In 1741 a French chemist Claude Joseph Geoffroy(1685-1752) discovered that when soap (which was prepared by cooking fat with alkali) decomposes with acid, a greasy mass is formed.

The fact that glycerin is part of fats and oils was first discovered in 1779 by the famous Swedish chemist Karl Wilhelm Scheele.

For the first time, the chemical composition of fats was determined at the beginning of the last century by a French chemist Michel Eugene Chevreul, the founder of the chemistry of fats, the author of numerous studies of their nature, summarized in a six-volume monograph "Chemical research of bodies of animal origin ".

1813 E. Chevreul established the structure of fats, thanks to the reaction of hydrolysis of fats in an alkaline environment.He showed that fats are composed of glycerin and fatty acids, and this is not just a mixture of them, but a compound that, by adding water, decomposes into glycerol and acids.

Total Fat (Triglyceride) Formula

Fats - esters of glycerol and higher carboxylic acids. The common name for such compounds is triglycerides.

Classification of fats

Soaps are potassium and sodium salts of higher carboxylic acids.

2. Hydrogenation of fats- the transformation of liquid vegetable oils into solid fats - is of great importance for food purposes. The product of the hydrogenation of oils is solid fat (artificial lard, salomas ). Margarine - edible fat, consists of a mixture of hydrogenated oils (sunflower, corn, cotton, etc.), animal fats, milk and flavorings (salt, sugar, vitamins, etc.).

This is how margarine is obtained in the industry:

Under the conditions of the hydrogenation of oils (high temperature, metal catalyst), some of the acid residues containing the C = C cis bonds are isomerized into more stable trans isomers. The increased content of trans-unsaturated acid residues in margarine (especially in cheap varieties) increases the risk of atherosclerosis, cardiovascular and other diseases.

The reaction of obtaining fats (esterification)

The use of fats

• 1. Food industry
• 1. Pharmaceuticals
• 1. Manufacture of soap and cosmetics
• 1. Lubricants production

Fat is a food product. The biological role of fats.

To provide the body with energy in unfavorable conditions, fat reserves are created in it, which are deposited in the subcutaneous tissue, in the fatty fold of the peritoneum - the so-called omentum. Subcutaneous fat protects the body from hypothermia (especially this function of fats is important for marine animals). For thousands of years, people have performed hard physical work, which required a large expenditure of energy and, accordingly, increased nutrition. To cover the minimum daily energy requirement of a person, only 50 g of fat is enough. However, with moderate physical activity, an adult should receive a little more fat with food, but their amount should not exceed 100 g (this gives a third of the calorie content with a diet of about 3000 kcal). It should be noted that half of this 100 g is contained in food in the form of the so-called latent fat. Fats are found in almost all food products: they are found in small quantities even in potatoes (there are 0.4% of them), in bread (1-2%), in oatmeal (6%). Milk usually contains 2-3% fat (but there are also special types of skim milk). There is quite a lot of hidden fat in lean meats - 2 to 33%. Latent fat is present in the product in the form of individual tiny particles. Almost pure fats are lard and vegetable oil; in butter about 80% fat, in ghee - 98%. Of course, all the recommendations given for fat intake are average, they depend on gender and age, physical activity and climatic conditions. With excessive consumption of fats, a person quickly gains weight, but one should not forget that fats in the body can be synthesized from other foods. It is not so easy to “work off” extra calories through physical activity. For example, after jogging 7 km, a person spends about the same amount of energy as he gets from eating just one 100-gram bar of chocolate (35% fat, 55% carbohydrates). Physiologists have found that during physical activity, which is 10 times higher than usual, a person on a fat diet was completely exhausted after 1.5 hours. With a carbohydrate diet, a person withstood the same load for 4 hours. This seemingly paradoxical result is explained by the peculiarities of biochemical processes. Despite the high "energy intensity" of fats, getting energy from them in the body is a slow process. This is due to the low reactivity of fats, especially their hydrocarbon chains. Carbohydrates, although they provide less energy than fats, "release" it much faster. Therefore, it is preferable to eat sweets before physical activity, rather than fatty ones. An excess of fats in food, especially animals, increases the risk of developing diseases such as atherosclerosis, heart failure, etc. Animal fats contain a lot of cholesterol (but we should not forget that two-thirds of cholesterol is synthesized in the body from non-fat foods - carbohydrates and proteins).

It must be remembered

Saturated fatty acids negatively affect fat metabolism, liver function and contribute to the development of atherosclerosis. Unsaturated (especially linoleic and arachidonic acids) regulate fat metabolism and participate in the elimination of cholesterol from the body. The higher the unsaturated fatty acid content, the lower the melting point of the fat. The caloric content of solid animal and liquid vegetable fats is about the same, but the physiological value of vegetable fats is much higher. Milk fat has more valuable qualities. It contains one third of unsaturated fatty acids and, remaining in the form of an emulsion, is easily absorbed by the body. Despite these positive qualities, milk fat alone should not be consumed, since no fat contains the ideal fatty acid composition. It is best to consume both animal and vegetable fats. Their ratio should be 1: 2.3 (70% animal and 30% vegetable) for young and middle-aged people. The diet of the elderly should be dominated by vegetable fats.

Fats are not only involved in metabolic processes, but are also stored in reserve (mainly in the abdominal wall and around the kidneys). Fat reserves provide metabolic processes, preserving proteins for life. This fat provides energy during physical activity, if little fat has been received from food, as well as in severe diseases, when due to decreased appetite it is not enough supplied from food.

Abundant consumption of fat with food is harmful to health: it is stored in large quantities in reserve, which increases body weight, sometimes leading to disfigurement of the figure. Its concentration in the blood increases, which, as a risk factor, contributes to the development of atherosclerosis, coronary heart disease, hypertension, etc.