Protein – requirements, function and occurrence

Proteins are the building blocks of life and vital for our body. While carbohydrates and fats are primarily used for energy production, proteins are true all-rounders among nutrients: our body uses proteins to build muscles, repair tissue, produce hormones and strengthen the immune system. However, more on this below.

Proteins are made of amino acids. Only 20 different amino acids are needed to form all proteins in the body. Nine of them cannot be produced by our body itself - these are called ‘essential amino acids’. They have to be taken in with food.

The combination of amino acids determines the specific function of each protein – from muscle growth to wound healing. Proteins can be categorised according to their function, including structural proteins, transport proteins, signalling proteins, storage proteins, motor proteins and enzymes:

• Structural proteins serve as structural building blocks for the body. These include, for example, collagen, which gives skin, bones and tendons their stability, and keratin, which forms hair, nails and the outer layer of skin. These structuralproteins are, so to speak, the ‘scaffolding’ that holds our body together.
• Enzymes are highly specialised proteins that enable and drive chemical reactions in the body – from digestion to metabolism and energy production.
• Transport proteins serve as freighters for vital substances that need to be transported throughout the body. In addition to haemoglobin, which transports oxygen through the blood, and transferrin, which transports iron to the cells, these also include albumin, which distributes fats and hormones in the blood, as well as lipoproteins in LDL and HDL particles that transport cholesterol. Transport proteins also include ion channels – proteins in the cell membranes that regulate the targeted transport of ions such as sodium, potassium or calcium. In this way, they control important bodily functions such as nerve impulses, heartbeat or muscle contraction.
• Hormones are among the signalling proteins. Hormones are messenger substances that reach their target organs via the blood and control important functions such as growth, metabolism and reproduction.
• Storage proteins help the body to store certain substances (e.g. ferritin).
• Reserve proteins: Proteins can also serve as an energy reserve in the body. In times when the intake of fats and carbohydrates is insufficient, amino acids from proteins can be broken down to produce energy.
• Movement proteins: Actin and myosin enable muscle contraction and movement.
• But immunoglobulins (antibodies) and receptors also consist of proteins.

This list shows that proteins fulfil a fascinating range of vital tasks in our body. Without them, human life would not be possible.

In our daily diet, proteins are primarily important for building muscle and maintaining it. The branched-chain amino acids, which athletes usually know as BCAAs – an abbreviation derived from the English term ‘branched chain amino acids’ – are particularly important for muscles. These amino acids, which can be obtained from food and dietary supplements, are used in the muscles as an energy supplier or basic building block. For this reason, proteins also play an important role in muscle regeneration.

Proteins are not only important for our sporting performance, they are also important for our hair and skin – as both, as mentioned above, consist largely of proteins themselves. The protein keratin repairs damaged strands and ensures strong and healthy hair. The protein collagen in turn strengthens the skin – and because collagen production decreases with age, it can be useful to take this protein in the form of a dietary supplement.

Structural proteins such as collagen are also extremely important for the health and stability of bones. They give the bones strength and resistance to fractures by forming the ‘scaffolding’, so to speak, that gives them shape and strength. In addition, bone tissue also contains elastin proteins, which ensure that the bones are not brittle and rigid, but elastic and resilient.

Proteins are also essential for bone growth in childhood and adolescence, as they provide the building blocks for the formation of new bone substance.

Even if you break a bone or suffer any other kind of injury, your body needs a lot of proteins to repair the bones and heal the wound. Without the high proportion of proteins in our bodies, our bones would be much more susceptible to fractures and injuries – so proteins play a crucial role in their stability, elasticity and ability to regenerate.

Proteins are also vital for the immune system. They are crucial for building and repairing body tissue and for defending against infections. A deficiency can impair the immune system.

And proteins can even help you lose weight. This is because a higher protein intake is associated with greater satiation and thus greater weight loss in a diet than a lower protein intake. However, you should make sure you get the dosage right – ideally in consultation with a doctor who specialises in nutrition. The right amount of protein not only helps you feel fuller, but also protects our muscle tissue while dieting.

The European Food Safety Authority (EFSA) recommends that adult humans take in at least 0.83 grams of protein per kilogram of body weight every day. For a person weighing 75 kilograms, that would be 62.25 grams of protein per day.

On average, athletes need a little more: around 1.2 grams of protein per kilogram of body weight per day. For real endurance or strength athletes, the optimal dose is even slightly higher, in the range of 1.6-2.2 grams per kilogram of body weight.

So now we know that proteins are important for us, whether we do sports or not. But how do you get as much protein as possible from your diet? Tofu is a classic that can be used in many ways because it can be used whole or pureed and takes on any flavour. Other good sources include beans of all kinds, chickpeas and quinoa. If you don't want to go without meat, lean meat is the best source of protein.

In any case, the view that animal proteins contribute better to muscle building or regeneration than plant-based proteins is outdated. The only thing that matters here is the CS (Chemical Score). This refers to a WHO reference protein. The reference protein defines the ratio of amino acids in the protein. A CS of 100 means that the body can almost completely utilise the amino acids from the protein for its own protein. The vegan protein sticks from BIOGENA with a chemical score of 198, are therefore an excellent source of protein.

Which is better – vegetable or animal protein? In the context of a balanced diet, there is actually no big difference, provided that the total amount of protein is sufficient. If you tend to eat a rather one-sided diet, a protein shake with a high chemical score (see above for an explanation) can be helpful. It is important to choose foods that are as wholesome as possible – nuts, lentils, beans, lean meat, fish, dairy products or eggs.

In Europe, most people have no problem getting enough protein – a real protein deficiency is therefore rare. Nevertheless, there are situations in which people in this country can be affected by a protein deficiency.

Some possible causes are:

• Low intake: People who eat little or an unbalanced diet, such as those on extreme diets or unbalanced vegan diets, often don't get enough protein.
• Increased needs: Older people often need more protein to stay healthy and should therefore pay particular attention to a protein-rich diet.
• Increased loss: Some people lose more protein than they can take in due to their lifestyle or certain physical exertion.
• Plant-based nutrition: For vegans and vegetarians, it is important to choose the right protein sources and to ensure a balanced combination of essential amino acids. By combining different plant-based protein sources, a high biological value can be achieved even without animal products.

Symptoms of a protein deficiency can include muscle weakness, tiredness, slower regeneration and brittle hair and nails. A conscious approach to high-protein foods ensures that the body remains healthy and productive.