Protein is an essential macronutrient for humans. They must be present in the diet and are made up of smaller pieces called amino acids .
Among all the amino acids that make up a protein, we find the non-essential (capable of being synthesized by the body itself) and the essential (which must be ingested through the diet).
Thus, we can say that a regular protein intake is essential for life. The most recent scientific articles claim that the consumption of this nutrient is able to prevent the development of diseases such as sarcopenia. However, there are several types of proteins depending on their origin and function.
Types of proteins: 2 possible origins
We can distinguish proteins of animal and vegetable origin . The former are of better quality than the latter. They are said to be of high biological value, because they have in their composition the 9 essential amino acids for humans.
In addition, they have the property of being highly digestible, which facilitates their absorption and use in human metabolism. The most perfect protein known to the animal world is that of the egg .
However, there are other sources like milk or very high quality meat. Indeed, protein supplements are generally based on whey protein isolates which allow a high intake of this macronutrient. Their use is recommended especially in intense exercise situations, according to research published in the journal Nutrients .
High biological value proteins are found in foods of animal origin. However, there are also plant foods that can provide us with this macronutrient, albeit in an incomplete way.
On the other hand, we have vegetable proteins which are generally incomplete. This means that they are deficient in at least one essential amino acid . It is therefore essential to combine different types of plant sources to obtain the correct intake of amino acids.
However, even if we manage to optimize this intake, the digestibility of vegetable proteins is much less . This means that their absorption and bioavailability are inferior to proteins in the animal world. In balanced diets, it is recommended that at least 50% of the intake of this macronutrient come from animal sources.
Functions of proteins
Proteins are macronutrients that have multiple functions in the body. One of the main, and what they are best known for, is their structural ability to build and repair bones, muscles, and other tissues . However, their functions go far beyond:
- They work like antibodies to defend us against foreign organisms.
- These are enzymes that speed up or enable physiological reactions that take place in the body.
- They allow internal pH balance by means of a buffer system.
- They play a role in muscle contraction.
- Proteins confer elasticity and resistance to organs and tissues.
- They are involved in the proper functioning of the nervous system.
- They can be a reservoir of energy.
- Proteins carry oxygen in the blood.
It is therefore clear that proteins can perform enzymatic, structural, defensive, storage, transport, receptor and motor functions .
Essential macronutrient
For all these reasons, protein is an essential macronutrient for human nutrition. Despite this, the current load of the Western diet tends to be higher than recommended .
While the literature recommends doses of between 1.2 and 1.6 g of protein per kg of weight for sedentary people, values of around 2 g are reached .
These values can be useful for strength or high intensity athletes. This is what a study carried out in 2015 confirms . However, in sedentary adults, it could be too stressful on the liver and kidneys , and does not offer too many benefits in terms of body composition.
Many people needlessly follow a high protein diet. In some cases, this is motivated by the sale of dietary supplements.
It is therefore recommended to reduce the protein intake slightly, except in cases of special needs. The combination of animal and vegetable sources is often a good dietary choice. It is interesting to choose foods from the plant kingdom with a high intake of this macronutrient, such as dried fruits .
Legumes are another interesting option, but in this case it is recommended to combine them with cereals to correct the intake of essential amino acids.
Include different types of protein in your diet
Proteins, along with fats, are the most useful macronutrients in the body. This is why protein intake is essential as part of a varied diet . Despite this, today’s society tends to over-consume it, especially due to the sale of protein supplements. Before consuming this type of supplement, it is worthwhile to consult a nutritionist to assess whether it is necessary or not.
In any case, the diet of a sedentary person should be marked by moderation and variety . Reducing the consumption of meat and increasing the consumption of fish, as well as introducing proteins from the plant world, are very healthy habits.
