In the field of nutrition, we speak of macronutrients to refer to the nutrients that the human being needs to ingest in large quantities. They are generally defined as the nutrients that provide most of the metabolic energy and most of the substances necessary for tissue formation and biochemical reactions.
Following this criterion, there are three groups of macronutrients: carbohydratesthe fats and the proteins. Some authors include water and dietary fiber as macronutrients, since they are necessary in the diet in large quantities although they do not provide energy.
Some substances that provide calories are not considered macronutrients because they are not substances necessary for life or because of their toxic effects, for example alcohol and some organic acids.
Some minerals, such as calcium, sodium, magnesium, and potassium, are known as macro minerals, there are even those who include them in the macronutrients, since they are needed in quantities much higher than the rest of the minerals. At the level of chemical elements, the elements most consumed by humans are carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, and they are referred to as macroelements.
carbohydrates
The human being needs to consume large amounts of carbohydrates. Are the most important energy nutrient group and dietary recommendations are typically above 50% of daily caloric intake. The RDA (Recommended Dietary Allowances) is the 50 – 55%with a maximum content of 10% simple sugars.
Carbohydrates provide an average of 4 cal/g and among them, without a doubt, the glucose, the main energy substrate for any cell in the body and essential for the functioning of the nervous system, the renal system and the muscular system, including the myocardium. In addition, they participate in many physiological processes, since they are part of numerous molecules, some as important as ATP, enzymes or DNA itself.
Most dietary fiber is made up of indigestible carbohydrates. Although they do not provide energy, dietary fiber is essential due to its effects on intestinal health and its consequences throughout the body, such as a lower risk of obesity or an improvement in cholesterol levels and the general lipid profile.
The main source of carbohydrates are cereals, fruits and vegetables, foods that also provide large amounts of other nutrients, such as vitamins and minerals. This nutritional contribution separates fruits and vegetables from other carbohydrate-rich foods with high caloric density but low amounts of other nutrients; These foods are said to provide empty calories and industrial bakery products and most sugary products stand out, the consumption of which should be sporadic and limited.
Meat, fish and animal products provide low amounts of carbohydrates, with some exceptions such as milk that is high in lactose and other carbohydrates.
protein
The main function of proteins is not energy but they are essential for many other reasons. For example, proteins make up the enzymes that catalyze most biochemical reactions and form antibodies that defend us from infections. Proteins are the main cell constituentgenerally represent more than 50% of the dry weight of a cell.
Although proteins provide calories, approximately 4 cal/g, the same as carbohydrates, their use as an energy source occurs in extreme cases when cells have a low availability of carbohydrates and lipids, which usually occurs in states of malnutrition
The RDA recommendations for protein is in 10% of daily caloric intake. The foods with the highest protein content are meat, fish, legumes, nuts, cereals and whole grains. The intake of protein of animal origin must be sporadic, especially of red meat and processed meat productsespecially due to the high amount of saturated fat and its carcinogenic effect.
lipids
Lipids, also known as fats, are the macronutrient that provides the most calories, 9 per gram. In energy metabolism, lipids have a role mainly of booking and not as a direct source of energy. Fats are also important for absorbing other nutrients, for example the fat-soluble vitamins (A, D, E, K).
Lipids are also necessary to form the biological membranesall of them are composed of a double lipid layer, cholesterol and various proteins.
The RDA is from 30 – 35% of daily caloric intake. Saturated fatty acids and high cholesterol levels are linked to an increased risk of cardiovascular diseasesThat is why the main sources of lipids should be vegetables, since they have a high proportion of unsaturated fat and do not contain cholesterol.
You should also avoid industrially produced fatty foods that may contain trans fat, a type of modified fat that also increases the risk of cardiovascular disease and other health problems.