What are proteins, fats, and carbohydrates needed for?

Lipids, fats: general overview

The fats that our body receives are represented by triglycerides, which are 10% glycerol and 90% fatty acids. According to nutritionists, the most healthy type of fat is the Omega family. All fatty acids are usually divided into two large groups. The first, monounsaturated, are essential, that is, if they are not in the diet, then the body cannot work fully, pathological conditions and diseases develop. Polyunsaturated fats are also essential. These are the basic elements of a healthy diet; they cannot be synthesized by the body and must come from outside. If this does not happen, then the consequences will not be long in coming. As a rule, this is a series of serious diseases that can exist asymptomatically for a long time.

What types of fats are there?

Unsaturated fats

To live and not strain, we need 4 polyunsaturated fatty acids: linoleic, linolenic, arachidonic and docosahexaenoic. They belong to omega-3 and omega-6 acids, the usefulness of which is well known among those who are interested in healthy eating.

These wonderful and well-known “omegas” lower cholesterol levels, cleanse and restore elasticity to blood vessels, prevent the formation of blood clots, have an antioxidant (also called “rejuvenating”) effect, normalize blood pressure, prevent strokes and heart attacks, improve blood supply to the brain and limbs, promote the renewal and development of central nervous system cells, accelerate the restoration of bone tissue and the formation of callus during fractures, and improve the condition of ligaments. Omega-3 acids also have an anti-inflammatory effect.

With a lack of omega-3, vision deteriorates, muscle weakness develops, and numbness occurs in the arms and legs. Children's growth slows down. Research suggests that when levels of omega-3 fatty acids in the blood are low, people are more susceptible to negative thoughts.

Omega-3 is found mainly in the inhabitants of the deep sea: fatty fish (mackerel, herring, sardines, tuna, trout, salmon, sprats, mullet, halibut) and other reptiles (squid, anchovies). In the plant kingdom, they are abundant in pumpkin seeds, soybeans, walnuts, dark green leafy vegetables, and vegetable oils (flaxseed oil, grapeseed oil, sesame oil, and soybean oil).

Linoleic acid (or omega-6 acid) normalizes fat metabolism, reduces dry skin, maintains the normal state of cell membranes, reducing fatty infiltration of the liver. Omega-6 acids are found in almost the same foods as omega-3. With a lack of omega-6, eczema can develop, hair loss, and dyslipidemia.

There is also an omega-9 fatty acid - monounsaturated oleic acid. The body can synthesize it, but it is advisable that it comes with food. Oleic acid is better absorbed and is the only one that has no effect on cholesterol levels. You can find it in olive and almond oil.

With a lack of omega-9: weakness develops, increased fatigue, poor digestion, constipation, dry skin and hair, brittle nails, vaginal dryness.

Saturated fats

They reduce sensitivity to cholesterol, and it leaves the bloodstream more slowly, which means the risk of cholesterol deposition in the walls of blood vessels increases. But saturated fatty acids have a plus: they provide the body with energy. The main thing is not to overdo it with them.

Saturated fatty acids “hang out” together with unsaturated ones. They are found in butter, lard, and meat.

Cholesterol

They scare them from television screens and in vain. Cholesterol, like all other fats, is very necessary, but in moderation and harmful if consumed in excess.

It is part of the cell membrane, from which sex hormones (estrogens, testosterone, progesterone) and stress hormones (cortisol, aldosterone), vitamin D and bile acids are synthesized. Cholesterol also increases the production of serotonin, the “good mood hormone,” so a depressed appearance with a low-cholesterol diet is quite natural.

However, the body produces most of the necessary cholesterol (approximately 80%) itself and approximately 20% comes from food. Excessive consumption of cholesterol threatens the formation of plaques in blood vessels with all the resulting diseases, such as atherosclerosis.

Cholesterol is found in animal products: eggs, dairy products, meat. The most cholesterol is found in animal brains and bird eggs, and slightly less in fish.

By the way, two egg yolks contain about 400 mg of cholesterol or the daily value.

Trans fats

This is a type of unsaturated fat. These fats are characterized by the presence of trans isomers of fatty acids, that is, the arrangement of hydrocarbon substituents on opposite sides of the carbon-carbon double bond - the so-called trans configuration. Actually, this explains their strange name for the average person.

The main breeding grounds for these not-so-healthy fats are margarines and spreads, which were created with good intentions as a cholesterol-free alternative to natural products. A small amount of trans fat is present in milk and meat.

Content of trans fats in food

Trans fats significantly increase the shelf life of products, which is why they are now replacing more expensive and perishable natural solid fats and liquid oils. The critical limit for trans fat consumption is 6-7 g per day. In order not to go over this norm, be especially wary of margarines, spreads, and cooking fats.

In addition, the problem with trans fats is the following - as a result of various manipulations, they lose most of their positive properties and acquire negative ones. They not only increase cholesterol levels, but also prevent the breakdown of unwanted fats and the formation of vital fatty acids.

The meaning of fatty acids

It is from fatty acids that highly active hormone-like substances are formed: prostaglandins, leukotrienes, etc. For example, prostaglandins control blood flow to organs, blood pressure, and in general, not a single physiological process takes place without their participation. Prostacyclins, for example, prevent blood vessels from sticking together and the blood from thickening. Leukotrienes are mediators of inflammation—the body’s defense response. In general, the entire family of polyunsaturated fatty acids protects the heart and blood vessels, converts cholesterol into more easily soluble forms, and the body removes it. A connection has been established between the deficiency of Omega acids and the occurrence of cancer pathologies and the more frequent formation of infectious diseases.

Omega-9 fatty acids

This Omega family includes several types of acids; their main sources are vegetable oils, seeds, salmon fish and other species.
The benefit of this family comes down to their active role in the prevention of metabolic syndrome, diabetes, and even some cancer pathologies.
These acids are also important for maintaining the functioning of the immune system. This class of acids prevents the formation of atherosclerotic plaques in blood vessels, which significantly reduces the likelihood of developing atherosclerosis and its consequences. Every day, Omega-9 acids should account for about 15-20% of the total caloric intake of the diet.
It is noteworthy that this need does not change depending on age.

Omega-6 fatty acids

This group includes linoleic and arachidonic acid. The sources of these acids are very extensive: vegetable oils, some berries, poultry, eggs, seeds, cereals, bread, etc.
Omega-6 fatty acids are especially useful for women and girls, as they maintain the beauty of the skin, but also reduce cholesterol levels and maintain normal blood clotting.
Omega-6 should account for 5-8% of the total calorie intake per day,
which is approximately 4.5-8 g of acid per day, but it is important to take into account the correct ratio of Omega-6 to Omega-3, which should be 4:1 . But, as practice shows, this ratio is not observed in the diet of modern people, and sometimes the diet contains tens of times more sources of Omega-6.

Omega-3 fatty acids

The source of these acids is seafood, especially in fatty and semi-fat fish.
They can also be preserved in canned food, although the benefits of canned fish cannot be compared with fresh fish.
Sources of these acids will also be vegetable oils, which are obtained from flax and sesame seeds.

Omega-3 fatty acids are found in smaller quantities in nuts, legumes, leafy vegetables, and broccoli. The main role of fatty acids is:

• strengthening cell membranes;
• improving the functioning of the brain, heart and blood vessels;
• normalization of emotional state;
• reducing pain sensitivity in joint diseases;
• normalization of sexual function in men and women;
• lowering cholesterol levels;
• normalization of hormonal levels;
• skin regeneration, that is, rapid healing of wounds;
• reducing the likelihood of developing cancer pathologies.

Omega-3 fatty acid deficiency

Research shows that today many people consume very little fatty acids - barely 50-70% of their daily requirement. Therefore, you need to reconsider your eating habits and make appropriate adjustments. The first thing you need to know is the optimal amount of acids in the diet. For example, a person needs only one gram of Omega-3 fatty acids daily.
But for them to be fully absorbed, you need 4 grams of Omega-6 fatty acids. Another important condition is the completeness of the diet in terms of caloric composition. If a person experiences a calorie deficit, in other words, is malnourished, then all fatty acids are broken down into simpler components and used to cover energy costs. And they cannot fulfill their intended purpose.

Text: Yulia Lapushkina.

What is fat and why do we need it?

Anyone who thinks about proper, balanced nutrition and the prevention of various diseases probably knows that the main components (macro-nutrients) of our food are proteins, fats and carbohydrates. The balance of calories, proteins, fats and carbohydrates in the diet is the basis for the harmonious growth and development of a person starting from childhood, the key to a long and healthy life in the future. But how to properly balance your diet? Should you count calories? How much protein should you eat per day and how to combine it with other food components? How to eat deliciously and not gain weight? How to eat so as not to get sick?

There is a lot of information, the Internet is full of contradictory facts, and it can be difficult to understand. Having accumulated enough questions and controversial answers to them, I eventually came to a serious study of nutritionology - the science of nutrition, which comprehensively and comprehensively studies the problems of nutrition of a healthy and sick person. I completed training in the specialty of General Nutrition from specialists (practicing nutritionists, therapists, cardiologists, endocrinologists and others) at the Center for Nutrition and Adaptive Nutrition at the Russian State Social University.

The knowledge gained during the training helped me understand the various processes occurring in the human body during the consumption and assimilation of food, and the relationship between these processes. Certain aspects that previously raised many questions and the answers to which had to be taken on faith have become clear. Now, having knowledge, you can draw sound conclusions and find the causes of this or that phenomenon. Nutritionology is now very actively developing, especially in the West, and this is a trend in the development of medicine in general. Every year more and more research is conducted in this and related areas, new data appears, and old knowledge is reevaluated. For myself, I realized that nutritional science captivated me so much that I am ready to constantly deepen my knowledge in this area (which I do regularly) and share it with those who are also interested.

Therefore, I am starting to publish a series of articles in which we will understand in detail how balance in nutrition is achieved, what role proteins, fats and carbohydrates play in the diet, and what other aspects of nutrition you need to pay attention to if you consciously approach your diet. health and the health of your family.

And we will start with such an ambiguous and demonized macro-nutrient as fats.

photo from open source

Fats

Fats in the chemical sense are water-insoluble organic compounds, also called lipids, which provide a variety of vital functions of the body. It is an essential component of human nutrition and a concentrated source of energy.

The term lipids basically describes fats as a chemical element in our body, while the terms fats and oils are most often used to describe dietary fats. The difference between oil and fat is that fats are solid at room temperature, while oils are liquid. Exception: tropical oils such as palm or coconut remain solid at room temperature, while fish fats, on the contrary, are liquid. At the same time, most liquid oils are of plant origin, and solid fats are predominantly animal.

If we talk about the human body, then fats are part of its composition. Everyone knows perfectly well where we can visually observe this fat, especially when it is in excess, but not everyone knows how important it is for us.

Why does a person need fats?

• Fats are part of cell membranes along with proteins, affect cell permeability and the transport of substances from and into the cell, regulate the activity of many enzymes, participate in the transmission of nerve impulses, muscle contraction, the creation of intercellular contacts, etc.
• Fats supply the body with energy and are stored in our body as an energy reserve or a kind of energy depot; with the complete oxidation of 100 g of fat, 38.9 kJ (9.3 kcal) is released, while with the oxidation of the same amount of carbohydrates or proteins, more than 2 times less is formed - 16.7 kJ (4.1 kcal).
• The layer of fat protects the body from hypothermia and mechanical damage, protects blood vessels and nerves from compression, and secures some internal organs (for example, kidneys).
• Fats regulate the functioning of the body at the hormonal level (some hormones are made up of them, for example, corticosteroids and sex hormones), they help the absorption of fat-soluble vitamins, participate in the synthesis of bile salts and vitamin D, and increase the bioavailability of lycopene and beta-carotene.
• Fatty acids are involved in the process of digestion and absorption of many important food components.
• Fats are a source of endogenous (formed by the body) water : after the oxidation of 100 g of fat, 105 g of water is produced, which, for example, is especially important for desert animals.

Almost all types of food contain all three components (proteins, fats, carbohydrates), but in different proportions. Food fats are a source of lipids in our body and also play an important role in our life:

• As mentioned above, fats provide us with energy in an amount twice as high as that from proteins and carbohydrates.
• the polyunsaturated fatty acids they contain . PUFAs are essential nutritional factors and must be supplied with food.
• Fats in food improve its taste and appearance, help you feel full , and it lasts longer, since fatty foods take longer to process in the stomach.
• A number of biologically valuable substances are supplied with fats: phosphatides (lecithin), sterols, tocopherols, PUFAs, etc. Insufficient intake of fat can lead to disorders of the central nervous system, weakened immunity, hormonal imbalances, deterioration of the condition of the skin, kidneys, vision organs and others problems. Experimental animals on a low-fat diet had less endurance and a shortened life expectancy.

As you can see, the role of fats for our body is very significant, and it is not for nothing that nature has endowed us with a mechanism for storing fat. However, nature had no idea that we would begin to absorb fat with or without reason, while taking a permanent sitting-lying position.

How much dietary fat should we consume?

photo from an open source
The physiological need for fat in men is on average from 70 to 154 g per day, in women - from 60 to 102 g, which approximately corresponds to 30-35% of the calorie content of food eaten per day. At the same time, vegetable fats should account for at least half of their total amount. For children and adolescents, consumption rates are slightly higher (30-35% from 2 to 3 years and 25-35% from 4 to 18 years), due to the high energy and plastic needs of the growing body. The minimum required amount of fat for feeding infants is 30%; breast milk usually contains 40-55% fat, which covers all the baby’s needs.

Excessive intake causes an increase in the amount of fat (namely, saturated fatty acids and cholesterol) in the blood and leads to excessive calorie intake. And limiting intake below 20% of the total caloric intake can cause a lack of fat-soluble vitamins, primarily vitamin E, and essential fatty acids, and will also reduce the level of “good” cholesterol in the blood plasma, which, in turn, will lead to increased levels “bad” cholesterol and other pathological changes.

However, you shouldn’t bother yourself with these numbers and specifically calculate the amount of fat in your diet. Our food, as a rule, contains a sufficient amount of fats for all necessary functions to proceed normally, and often there is too much of them , since they can be disguised in finished products (such as sausages, semi-finished products, fast food, etc.). What's really important for us is to reduce fat intake overall, but not eliminate fat altogether . To do this, you need to keep frying in oil to a minimum (giving preference to such cooking methods as stewing and baking) and not buy products with a fat content above 5% if you already have prerequisites for obesity or problems with the cardiovascular system . Since saturated fat and trans fats are the most dangerous for us, we first of all pay close attention to products containing them - there should not be too much of them in the diet. We’ll talk about what types of fat these are, where they are found and why they are dangerous, but first we’ll figure out what kind of fats there are.

What types of fats are there?

There are animal fats and vegetable fats. The main sources of animal fats include: lard (90-92% fat), butter (72-82% fat), fatty meat (up to 50% fat), sausages (20-25% fat), cheeses (15-40 % fat), sour cream (10-30% fat), cream (10-30%) and other dairy products. The main sources of vegetable fats are vegetable oils (contain up to 99.9% fat), nuts (53-65% fat), plant seeds (up to 50% fat), cereals (for example, oatmeal - 6.1% fat, buckwheat - 3.3% fat).

Fatty acid:

Products are sources of fat (photo from an open source)
An important component of any fat is fatty acids. Depending on the type of hydrogen bonds between carbon atoms, the following types of fatty acids are distinguished: saturated , monounsaturated and polyunsaturated . The fewer hydrogen bonds, the harder the fatty acid molecule (these are solid fats, usually of animal origin). Accordingly, the more polyunsaturated bonds a molecule contains, the more flexible it is in structure and therefore unsaturated fats are liquid at room temperature.

Skeletal muscles use both glucose and fatty acids for energy. Glucose is used primarily during short-term intense muscle work, and fatty acids are the main source of energy for resting or long-term working muscles. Muscles are able to store carbohydrates in the form of glycogen, and fats in the form of triglycerides, but in a certain, rather limited amount.

All fatty acids that the muscles were unable to store in reserve go to the liver, which uses them to synthesize triglycerides, which in turn pass into the blood. But you don’t need a lot of blood fat - it simply won’t be able to “use” it for its intended purpose (for plastic and other needs). Since fat does not dissolve in water (read: blood), it needs special transport - like a car for an official. This transport is carried out by lipoproteins – transport molecules of fat. If at some point the body has less lipoproteins than synthesized triglycerides, then the excess of the latter accumulates in the liver cells in the form of fat droplets, which in an advanced state leads to the development of fatty liver degeneration. This is far from the only problem that arises from excess fat in the diet, and we will return to discuss it later. It is important to understand that not all fats are dangerous for us, but only one of them is the so-called “bad cholesterol”. And even he was conceived by nature as a helper (more about this here), but man himself makes him an enemy, mindlessly absorbing in wild quantities those products that, under the conditions of civilization and developed industry, suddenly turned out to be so easily accessible. In everything you need to know when to stop.

In the next article we will talk to you about the difference between saturated, mono- and polyunsaturated fatty acids and their families such as omega-6 and omega-3.

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Hidden fats

A lot of fat is hidden in foods that we are not used to thinking of as fatty: avocado, doctor's sausage (“After all, there are no “eyes”!”) or chocolate. A person can eat 100 grams or more of such hidden fats per day without noticing.

Where is the most fat?