Every cell in the body needs nutrients that come from food and the environment. The body breaks down substances and synthesizes from them others that are necessary for its growth and vital functions, and removes all unnecessary products of processing. Our body also uses nutrients to renew and repair (heal) organs and tissues.

The human body needs the following nutrients to function properly:

 Fats
 Carbohydrates
 Proteins
 Vitamins
 Minerals
 water.
 

Some substances are macronutrients (proteins, fats, carbohydrates), and the rest are micronutrients (vitamins, minerals).

Macronutrients are essential nutrients that the body needs on a daily basis in fairly substantial amounts. It is they who, during oxidation, provide the body with energy to perform all tasks and "patch up wounds".

Micronutrients are needed in small doses. By themselves, they do not provide energy, but they are necessary for the assimilation of food, the release of energy, the establishment of vital processes and the development of the body.

Different substances have different main functions in the body. Some of the nutrients can be produced by the human body itself, while others come exclusively from the outside – such substances are called essential substances.

Essential nutrients include 10 amino acids that make up proteins, certain fatty acids, as well as some vitamins and minerals that the body itself is unable to produce, and their lack leads to the development of various diseases.

Proteins
 

They are needed for the synthesis of essential amino acids. Our body is built from proteins. Proteins are divided into animal (meat, fish, milk, eggs) and vegetable (nuts, mushrooms, legumes). These two types of proteins have different properties. Mainly from animal proteins, the body receives essential amino acids, which are not produced by the body on its own.

Proteins are responsible for transporting nutrients through the bloodstream, maintaining water balance, and the functioning of the immune system. The lack of proteins in the body leads to physical exhaustion, ailments, fatigue, as well as a violation of the acid-base balance in the body.

The protein requirement is calculated using the formula of about 0.8 g per kilogram of body weight, or 25% of the total caloric intake per day. Of these, 20% should be proteins of animal origin.

Carbohydrates
 

The main source of energy. Carbohydrates are broken down into water molecules, CO2 and ATP (energy carriers). With an acute deficiency of carbohydrates, the body is forced to extract energy from proteins and fats, spending a large amount of resources and enzymes for this. The process puts a lot of strain on the digestive system, liver and kidneys.

Carbohydrates are divided into three types: simple, complex, and fiber. Simple (fast) ones are those that break down quickly and release energy, as well as raise blood glucose levels quickly. Sources of simple carbohydrates are white flour bread, fruits, sweets, honey, etc.

Complex (slow) carbohydrates are energizing for a long time, they are broken down into simple carbohydrates within about an hour, slowly raising blood glucose levels. Complex carbohydrates are found in cereals, potatoes, etc.

The human body needs carbohydrates, which are converted into glucose. Part of glucose is used for energy production, and part of it is stored in the liver.

Fiber helps in the organization of the normal digestive process. It stimulates the intestines, nourishes beneficial microflora. It is found in vegetables, fruits, wholemeal flour. The daily requirement for fiber is 20-60 g. You can always make up for its deficiency with the help of bran (if there are no contraindications). We wrote about how to properly introduce bran into the diet in the article "Wheat bran: benefits and harms for the body".

By the way, bran helps the body to get not only coarse fibers, but also an additional portion of vitamins and nutrients, in particular vitamin A, groups B, E, K, nicotinic acid, calcium, magnesium, sodium, phosphorus, magnesium, iron.

On average, a person needs about 300 grams. carbohydrates per day or 50% of the total caloric intake of the diet should consist of carbohydrate foods.

Fats
 

Fats help conserve energy and protect internal organs from damage. They also protect the body from hypothermia. Fats are also necessary for the normal absorption of vitamins A, D, E, K, and steroid hormones and phospholipids are synthesized from them.

Fats are made up of fatty acids (FAs). Fatty acids are divided into saturated and unsaturated. Saturated LCDs are LCDs of animal origin. Unsaturated FA is obtained from plant foods and fish oil.

The lack of fats in the diet disrupts the hormonal background. The amount of omega fatty acids (Omega-9, Omega-3, Omega-6) consumed, which equalize cholesterol levels, are necessary for the elasticity of blood vessels, work as antioxidants, and have anti-inflammatory activity, is important for health.

Cholesterol. Cholesterol deserves special attention in the topic of fats. It is an organic fat-like substance, a natural polycyclic lipophilic alcohol that is found in the cell membranes of living things. The body produces 75% of cholesterol on its own, mainly in the liver and small intestine. The remaining 25% comes from food.

It is believed that cholesterol is divided into "good" and "bad". In fact, the substance is the same, but the difference is in the "packaging", lipoproteins, which transport cholesterol throughout the body.

"Good" cholesterol is "packaged" into high-density lipoprotein (HDL). "Bad" cholesterol is in low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). They "cling" to microlesions inside the vessels and stick to the walls, forming plaques. "Bad" cholesterol comes from fatty meat foods, and "good" cholesterol comes from fish and vegetable oils. But even "bad" cholesterol is necessary for a person. It is an important structural component of cell membranes and is essential for maintaining their integrity and fluidity.

The daily requirement for fats is 25% of the caloric intake. Animal fats should be consumed in a ratio of no more than 10% of the total caloric intake.

Vitamins & Minerals
 

Vitamins and minerals are found in both animal and plant foods. They are necessary for the establishment of biochemical processes of the body. They are also activators of chemical reactions in the body. Individual vitamins affect certain bodily functions.

The importance of vitamins for the body

Name
Meaning
A – Retinol
Protein synthesis, support of immune responses, visual functions, skin elasticity.
B1 – thiamine
Extracting energy from carbohydrates, healthy nervous system.
B2 – riboflavin
Formation of red blood cells, regulation of growth and reproductive function, health of the skin, nails, hair.
B3, PP – niacin
Metabolism of fats and carbohydrates, memory.
B4 – choline
Fat metabolism, nervous system function, regulation of insulin and cholesterol levels.
B5 – pantothenic acid
Metabolism of fats and proteins.
B6 – pyridoxine
Metabolism, blood circulation.
B7, H – biotin
Balance of fats and proteins, synthesis of enzymes.
B9 – Folacin
Transmission of genetic information, hemoglobin level.
B12 – cyanocobalamin
Hematopoiesis, hemoglobin level.
C – ascorbic acid
Collagen formation, vascular elasticity, protective reactions of the body.
Group D – ergocalciferol, cholecalciferol, dihydrotachysterol.
Absorption of calcium and phosphorus, formation and growth of bones, development of teeth.
E – tocopherols
Protection of cell membranes from damage, blood circulation, muscle growth.
K – phylloquinone
Blood clotting.

Many minerals are also involved in the work of the body. Minerals are divided into two groups: macronutrients and micronutrients. They differ in that a person's need for macronutrients ranges from a few grams to a few milligrams per day, while the need for micronutrients is ten times less.

Deficiency of macronutrients and micronutrients also leads to the development of various pathologies.

The role of the most valuable minerals in the human body:
Sodium – Maintaining the volume of fluid outside the cells and helping the cells to function.

Calcium and fluoride promote healthy teeth and bones.

Iron – formation of hemoglobin, maintenance of cholesterol levels.

Zinc – growth, tissue repair.

Copper – hematopoiesis, cell respiration, collagen synthesis, glucose oxidation.

Manganese – cellular metabolism, muscle growth.

Chromium – Maintaining glucose tolerance.

Iodine is the synthesis of thyroid hormones, the health of the reproductive system.

Selenium – immunity, detoxification.

Molybdenum – metabolism of macronutrients, regulation of uric acid levels.

Water
 

Water is needed by the body to transport nutrients and oxygen to the body's cells. It also helps to convert nutrients into energy and assimilate them, and is involved in all chemical and biological processes of the gastrointestinal tract. Maintaining a normal body temperature also depends on water. It also plays a role in protecting internal organs, is involved in maintaining cell shape, and is important for the health of all tissues. Water, among other things, becomes a source of many minerals for us. It is believed that an adult needs to consume about 1.5 liters of fluid per day. The exception is residents of hot countries and athletes, they need more water compared to others.