Proteins
Proteins are one of the three energy-providing macronutrients. They serve as building material for the body’s own proteins, which have many different functions. The sufficient supply of proteins and their quality is crucial for a healthy diet.
Our facts in brief summarized for you!
- Proteins are important building materials for the body.
- They are used to build the body’s own proteins, which make up 15–17% of the body’s mass.
- Proteins provide excellent satiety and are important for a healthy body.
- Both animal and plant foods are optimal sources of protein
What are proteins?
Proteins are components of our food and belong to the macronutrients. Structurally, proteins are long chains of individual amino acids. There are 20 proteinogenic amino acids, 9 of which are essential. The body cannot produce them itself and must therefore obtain them from food. Amino acids are necessary to produce the body’s own proteins. Not only our food contains proteins, they are also present in our body in certain quantities. Proteins are the most important biochemical function carriers. The total amount of proteins is 15–17% of the body mass of an adult.
What are proteins needed for?
Since the body is made up of over 1/7th proteins, they take on some important functions. If you think of proteins as muscle building, you only know part of the truth. Because proteins or the individual amino acids serve as starting material of most diverse substances. They are building material, enzymes, hormones, receptors, transport proteins, neurotransmitters or muscles: they are all built with the help of proteins.
In contrast to fats and carbohydrates, proteins are used less as a source of energy. One could almost think they are too valuable for that. In hunger phases, however, they can also serve as a source of energy. This involves the release of amino acids from the muscles and sugar is produced from them in the course of gluconeogenesis.
Muscle tissue is metabolically highly active. More muscle usually means a healthier body. However, muscle breakdown occurs in middle age and increases with age. Since muscle loss not only increases the risk of falling in old age, but also increases the risk of chronic diseases, it is important to counteract this. This is best achieved with physical exercise such as strength training, as well as by consuming sufficient, high-quality protein.
How much protein does the body need?
The German Nutrition Society (DGE) recommends a daily protein intake of 0.8 g per kilogram of body weight. A person weighing 100 kg would therefore have a protein requirement of 80 g per day. However, protein requirements are subject to age-related fluctuations and other influencing factors. For example, infants and children, heavy workers, pregnant women and strength athletes have a higher requirement.
Preventing muscle loss or even building up muscle is therefore an important pillar for a healthy body. Physical activity also results in a higher protein requirement. A good rule of thumb is 1g/ kg body weight protein for non-athletes and 1.5 g/ kg body weight for athletes. However, more is usually not necessary.
The consumption of protein has a particularly satiating effect, which is why a protein source should be part of a full meal. By the way, as long as enough is drunk, high protein consumption does not harm the kidneys. If kidney disease already exists, increased protein consumption can be a problem and should be discussed with a doctor.
What are good sources of protein?
Not only is a sufficient amount of protein important, but also its quality. This can be assessed with the help of the biological value. The composition of the amino acids of the dietary protein determines the value. The more this corresponds to the composition of body protein, the higher the biological value.
In general, it can be said that animal protein sources such as fish, meat and eggs have a higher value than vegetable protein sources. However, studies have shown that combining different plant protein sources increases their overall value. Thus, while plant foods in isolation are inferior to animal foods, in combination they can match the value of animal foods. Good examples of plant-based protein sources include cooked legumes, soy, tempeh, nuts and seeds. A good protein supply with a purely plant-based diet is challenging, but can be designed with the right and high-quality protein combination.
Since consumption of plant-based protein is associated with numerous health benefits and animal protein sources have the best composition of amino acids, combining the two probably makes the most sense from health perspective. A healthy diet should generally be largely plant-based, but can be usefully supplemented by combining select animal products.
Text-Sources:
(1) Biesalski, H. (2018) Ernährungsmedizin. (5. Auflage) Georg Thieme Verlag.
(2) https://next.amboss.com/de/article/Jo0s1S?q=protein#Y377144bcd24f3eb9bdd5aff10e9cd01a
(3) Wilkinson DJ, Piasecki M, Atherton PJ. The age-related loss of skeletal muscle mass and function: Measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans. Ageing Res Rev. 2018 Nov;47:123–132. doi: 10.1016/j.arr.2018.07.005. Epub 2018 Jul 23. PMID: 30048806; PMCID: PMC6202460.
(4) Martin, W.F., Armstrong, L.E. & Rodriguez, N.R. Dietary protein intake and renal function. Nutr Metab (Lond) 2, 25 (2005). https://doi.org/10.1186/1743-7075-2-25
(5) Young VR, Pellett PL. Plant proteins in relation to human protein and amino acid nutrition. Am J Clin Nutr. 1994 May;59(5 Suppl):1203S-1212S. doi: 10.1093/ajcn/59.5.1203S. PMID: 8172124.
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