Macronutrients: what they are, types and functions in the human body

Macronutrients They constitute one of the most important concepts in the world of health and nutrition. Let's see how they are, what are their types and how they influence the functioning of our body.

• Related article: "What is the difference between food and nutrition?"

What are macronutrients and what is their importance?

From a nutritional point of view, macronutrients are those compounds that provide most of the body's metabolic energy. These are carbohydrates, fats, and proteins.

We must bear in mind that we are facing a merely utilitarian grouping, because despite having all these nutrients Composed of molecules of an organic nature, they have little to do with each other beyond the energy contribution that they suppose for the human being.

Even so, like all classification criteria, this way of grouping foods is of immense use in the nutritional field. If you want to know the particularities of each of the macronutrients and what is the role they play on our physiological well-being, stay with us

The terminological conglomerate that refers to diet and health is increasingly present in the general population and it is not for less, since the World Health Organization calculated that in 2010 20% of the adult population and 10% of the child population had some type of disorder related to obesity. In 2016, these figures reached more than 650 million people.

Therefore, it is not at all strange to know that the leading cause of death in high-income countries is heart disease. This type of information is not merely anecdotal, as it shows that it is necessary to know the distribution of calories in our diet, what is best for us to eat and what limit. Again, it is not about prohibiting but about knowing, because few foods are truly harmful. As they say, control is the key.

Types of macronutrients

Once the importance of dietary knowledge by the general population has been defined, it is time to immerse ourselves in the world of macronutrients. Read on, as we thoroughly dissect each of the groups with data and statistics of great interest.

1. Carbohydrates

Carbohydrates or carbohydrates group a series of biomolecules that are composed mainly of carbon, hydrogen and oxygen. It is necessary to emphasize that these macronutrients are the main source of energy for humans, as they are the fuel of 50 to 80% of the daily metabolic expenditure of a relatively active person.

Beyond being an excellent source of immediate energy, carbohydrates form an integral part of our physiology and genes: our species has about 10 grams of carbohydrates for each kilogram of tissue, and the pentoses that give rise to each of the nucleotides of our RNA and DNA chains are carbohydrates simple.

We can divide carbohydrates into monosaccharides, disaccharides, oligosaccharides, and polysaccharides according to their chemical structure. Nor do we want to turn this space into a complex lesson, so we will limit ourselves to saying that monosaccharides are the simplest molecules and polysaccharides the most complex, the latter being made up of chains of more than 10 monosaccharides.

Special mention is required of monosaccharides and disaccharides considered as free sugars, since of course they are the most controversial group within carbohydrates. Here we find galactose, fructose or glucose among others, which are usually found in fruits or are added artificially in sweet products.

The World Health Organization recommends that only 5% of daily nutritional energy come from these sources, as it has been shown to have an oxidizing activity that promotes cell aging, in addition to other more immediate effects such as the formation cavities.

On the other hand, the rest of carbohydrates such as starch (a polysaccharide) are excellent nutritional elements. This is found, for example, in potatoes, rice, corn, cereals and fruit. We must bear in mind that carbohydrates make up the majority of the dry weight of plant matter, so we are dealing with the most abundant nutrient on Earth.

• You may be interested in: "Carbohydrates: what are they, types and characteristics of these molecules"

2. Protein

In the next group we have proteins, a series of linear macromolecules made up of chains of amino acids. From a nutritional point of view, it is estimated that they should not account for more than 15% of the daily caloric intake in the individual. In most Western countries, meat is the most consumed protein source, since together with milk and certain cereals it accounts for 75% of the proteins consumed in the diet.

Beyond what many people believe, protein is not a macromolecule only linked to the animal kingdom, since vegetables such as lentils, chickpeas and many others also produce them. In recent years, products such as red and processed meats (such as hamburgers or sausages) have been placed in the spotlight, as they have been classified into groups of "potentially carcinogenic" and "confirmed carcinogenic" respectively. What does this mean?

Consuming 50 grams of processed meat per day has been observed to increase the risk of cancer colorectal by approximately 18%, which is why they have been classified as carcinogenic compounds confirmed. This is because, during its production, harmful compounds such as N-nitroso and polycyclic aromatic hydrocarbons are formed. Red meat does not have such a clear direct correlation with carcinogenic processes, but it is still suspected that they may also favor them.

Even so, proteins are necessary for the development of tissues, for the maintenance and repair of the body, for enzyme production and many other vital processes, so we cannot reject its consumption of no way. For this reason, protein sources alternatives to red or processed meat are increasingly on the rise, such as such as chicken, turkey, tuna and a diverse group of legumes that can be deliciously combined in the diet.

3. Fats

Finally we have the group of fats, a generic term that designates several classes of lipids, a series of organic molecules that are mainly made up of carbon and hydrogen. As surprising as it may sound, nutrition experts recommend that 20-30% of daily calories should come from fat, that is, more than protein.

For a large part of the general population the term "fat" refers to the sebum of animal tissues, but this is a wrong preconception. Unsaturated fats are positive for the human body, as they are an excellent source of energy and are found naturally in vegetable oils, nuts, fish such as salmon or trout and dairy products such as yogurt or cheese.

The problem comes when we approach the field of unsaturated or trans fats, that is, those found in cakes, fried foods and other ultra-processed foods. Fat consumption must be balanced and of natural origin, as this type of processed food is clearly associated with heart disease and other ailments.

It is not strange that the United States breaks obesity records on an annual basis, since more than 36% of the caloric intake of an inhabitant in this country corresponds to fats, especially of natural unsaturated. On the other side of the coin we have various countries in the global South, where daily fat intake rarely exceeds 8-10% of the total metabolic requirement. Therefore, we are not surprised to learn that more than 821 million people suffer from hunger.

Resume

These last lines have yielded a key idea that we want to emphasize: none of the macronutrients are bad if eaten in the right amounts. Even the most dubious famous terms such as fats are essential for the diet and metabolic expenditure of the body. In general, we can affirm that more than half of the energy obtained in the diet must come from carbohydrates such as starch (always limiting the free sugars), an approximate 15% should come from animal or vegetable proteins, and the remaining 20-30% from fats, especially unsaturated from origin natural.

This does not mean that we should categorically reject processed meats for their carcinogenic potential or ultra-processed foods for the “empty calories” they entail. Emotional well-being is as important as physical well-being, and therefore becoming a slave to dietary numbers is never a good idea: control is the key.

Bibliographic references:

• Distribution of macronutrients and food sources in the Spanish population: results obtained from the ANIBES scientific study. Picked up on October 11 at http://www.fen.org.es/anibes/archivos/documentos/ANIBES_numero_7.pdf.
• Hunger in the world continues to increase, warns a new report from the UN, World Health Organization (WHO). Picked up on October 11 at https://www.who.int/es/news-room/detail/11-09-2018-global-hunger-continues-to-risenew-un-report-says.
• Macronutrients: Carbohydrates, Fat and Protein, FAO.org. Picked up on October 11 at http://www.fao.org/3/w0073s/w0073s0d.htm#:~:text=Los%20carbohidratos%20son%20compuestos%20que, of% 20starches% 20y% 20various% 20az% C3% BAcares.
• Obesity and overweight, WHO. Picked up on October 11 at https://www.who.int/es/news-room/fact-sheets/detail/obesity-and-overweight.
• Reducing the intake of free sugars in adults to reduce the risk of non-communicable diseases, WHO. Picked up on October 11 at https://www.who.int/elena/titles/free-sugars-children-ncds/es/.