What is a proteins?
A proteins is one of the three macro nutrients (= nutrient that provides energy ) essential to the proper functioning of our body, alongside carbohydrates and lipids .In common parlance, we often tend to speak of “proteins” through misnomer. In reality, there is a difference between the two terms. Unlike proteins, proteins are, so to speak, a “family” of proteins, amino acids and peptides – while proteins are molecules that are part of the family of proteins.
The role of the proteins
Proteins are essential in the functioning of the human being: they are present in all the cells of our organism .
Present in many forms, they perform various functions within our organization :
- They form and maintain the structure of the components of our body(e.g, bones, muscles, etc.).
- They participate in cell renewal:The amino acids found in the proteins we eat are absorbed and then used by the body to replace damaged or ineffective cells.
- Thanks to their nitrogen content, they have what is called a compensatory role: they compensate for our losses in urine (nitrogen released by the urinary or fecal route) thanks to the ingested nitrogen contained in the diet: in the proteins in the occurrence.
- Proteins can perform specific functions such as the protection of our body face to face the outside (example: hair, nails, skin …) or the contraction of muscles (case of “contractile” proteins: actin).
- Other proteins provide physiological functions such as digestion(case of enzymes), the transmission of information (case of neurotransmitters), immune defense (case of immunoglobulins), etc.
- Proteins also have an energetic role. Indeed, they allow the creation of energy. This role is nevertheless secondary and appears only in the case of prolonged fasting: the body then degrades the proteins to provide energy to our organism, nevertheless this has the disadvantage of causing muscular fetuses, decreases of the muscular tone, to see more serious problems.Protein deficiencies As we have seen, proteins are present in all cells of our body and they perform a whole lot of different functions. For this reason, insufficient intake of protein would have serious consequences for our body .Not knowing how to synthesize amino acids and having no reserves, our body will draw the proteins in the muscles to be able to function properly. This results in significant muscular wasting – just as important for athletes as for the rest of the population.Risks of excessA hyper-protein diet leads to risks of deficiencies in minerals and trace elements . It can also cause kidney complications because the extra protein is very demanding on our kidneys.The main sources of proteins
Proteins can come from two different sources: foods of animal origin and foods of plant origin :
– Animal proteins are provided by red and white meats, cold cuts, fish and seafood, eggs, milk, cheese and dairy products (yogurt, cottage cheese). They are richer in essential amino acids than vegetable proteins and better digested . Foods of animal origin are characterized by their high protein content of high nutritional quality (essential amino acid composition, digestibility, etc.).– Vegetable proteins, they come from two major sources: cereals (wheat, oats, rice, corn, etc.) and legumes (soy, lentils, beans, peas). Some vegetable proteins may have a limiting content of essential amino acids, so it is recommended to combine different plant foods to provide our body with all the necessary amino acids and thus allow the optimal functioning of our cells. Indeed, because the absence or insufficiency of an amino acid blocks or limits the synthesis of new proteins, which could have disastrous consequences on the functioning of our organism.
It is important, however, to vary the origin of the proteins . This can affect the coverage of other nutrient requirements. So:
- a diet exclusively of plant origin can lead to a risk of vitamin B 12 deficiency .
- a diet rich in animal protein can lead to insufficient fiber intake and excessive saturated fat .