They are the substances with the most functions in our bodies. Find out how and from where to get them.

The word protein is Greek: proteios means primary. This shows just how important proteins are to our lives. In fact, they are the most abundant component of our bodies, after water.

They are the structural component of our bodies, in other words the bricks and building materials with which the tissues of the organs are built: muscles, bones, ligaments, nails and hair. As well as making new tissues or repairing those existing, these molecules control bodily fluids such as urine and bile, and they are responsible for making hormones, enzymes, antibodies and haemoglobin in the blood.

In short, proteins are a part of all processes of life, from creating defences to disease to ensuring the proper functioning of the body.

How much should we ingest?

Everyone, regardless of age, needs protein. However, our daily requirements are different depending on age, sex and physiological condition. The World Health Organization recommends ingesting 0.8 gram per kilo of weight every day:

• Children from seven to ten years: 28 g/day
• Men aged more than 25 years: 63 g/day
• Women aged more than 25 years: 50 g/day

During growth, pregnancy or breastfeeding, these needs increase (by 10 to 12 grams daily).

With this in mind, every week it is recommended you eat fish seven times, pulses twice, white and lean meats twice, eggs twice and red meat once.  Likewise, you must control portion sizes (a normal portion is 20 grams): 120 g of white fish contains more or less this amount of protein, as do two eggs or a 100-gram chicken breast.

The Spanish Nutrition Foundation says that we eat far more protein than we should. If we eat more fish or meat, we absorb double the protein, which raises cholesterol levels and puts pressure on the kidneys and liver.

Which foods contain them?

Proteins are made up of basic units called amino acids. There are 20 different types of these: Nine are essential and the body is not capable of making them (such as tryptophan and leukine) and the others are non-essential fatty acids, which the body synthesises internally (cystine and glutamic acid)

Our bodies need to get proteins with essential amino acids from food, so it is essential to include certain ingredients of animal and vegetable origin in our diets.

• Of animal origin:

Proteins of animal origin are large, complex molecules, which is why they contain large qualities and more different animo acids. This gives them higher biological value than those of vegetable origin.

However, they are more difficult to digest, and they tend to be accompanied by unsaturated fats, which may increase the risk of suffering from cardiovascular diseases.

• Of plant origin:

Although vegetable protein is of lower quality than animal proteins, when combined with cereals and pulses, they can replace meat and eggs. For example, eating peas with noodles, chick peas with rice or cereals with milk gives the body balanced amino acids.

From this group, the healthiest proteins come from legumes, cereals (oats, quinoa, soybeans), dried fruits and vegetables (broccoli, spinach, green beans). They do not increase cholesterol and are a source or fibre, which is easy to digest.

This post is also available in: Spanish