Protein, or more technically, is one of the three macronutrients, along with fat and carbohydrates, that supplies our body with energy, among other things. Proteins can be broken down into their smallest parts, the amino acids. These have countless functions in our metabolism. The formation of enzymes, support of Detoxification processes and the Immune defense , muscle development and maintenance are just a few examples. Hair, skin and nails are also formed and held together by proteins, and our DNA, which controls our genes, retrieves information via amino acids. It is obvious: high-quality protein sources are essential for life. There are many plant and animal protein sources - but which of them are well tolerated and suitable for a sports diet?

Why do we need protein sources?

protein is only secondarily an energy source that our body needs as fuel. Normally, it uses fatty acids and Sugar Protein has many other vital functions.
Approximately 15 to 17% of our body mass consists of Proteins 1 . The word protein is derived from the Greek term “proteos”, which means “first” 2 . This already says a lot about the importance of this nutrient: proteins have a number of functions in the human and animal body, which will be discussed in more detail in the next section.

There are numerous different Proteins , which accordingly also take on different tasks in our organism. First of all, it should be made clear that proteins consist of amino acid chains. In nature, there are several hundred different amino acids, but our body only needs 20 of them. Another blog article will follow on the topic of amino acids, because their individual components and specific functions should be described in more detail. However, it is important to know in order to understand proteins that they are made up of chains of these 20 different amino acids that are relevant to us. Our organism can actually produce twelve of them itself if necessary, but the remaining eight must be consumed regularly through food. This clearly shows that foods must be eaten whose Proteins consist of at least these 8 essential amino acids.

Our body can produce amino acids Proteins and break down proteins into amino acids. Both serve to form substance complexes that the organism needs for numerous functions and structures. Some Proteins The purpose of producing enzymes that are needed in many processes such as digestion. Many organs require amino acids to produce the right substances that contribute to their functions. The liver needs the substances to detoxify, convert other substances or regenerate cells.

Structural proteins hold our muscles, tissue, bones, cartilage, hair and nails together. Foods containing protein play a major role in building muscle.

How is protein digested?

When we eat protein sources such as fish, meat or nuts, the breakdown begins in the stomach. Strictly speaking, the food is broken down in the mouth by the teeth, but unlike with carbohydrates, no enzyme is released into the saliva that can break down the proteins.

In the stomach, however, the mucous membrane cells produce hydrochloric acid, which Proteins in a first step. The hydrochloric acid also activates the enzyme pepsin, which Protein chains split off from each other 3 .
The next and last important station in protein digestion is the small intestine. There, the smaller chains are broken down into amino acids, because ultimately only these small particles can pass through the intestinal mucosa and enter the bloodstream 3 . Only from there do the amino acids reach all the cells and organs where the body needs them.

What are good sources of protein?

It actually seems quite simple: you just have to eat enough protein sources - with proteins that consist of the 20 different amino acids that our body needs. You might think that it doesn't matter whether the source is animal or plant-based or whether it is partly found in industrially produced products.

However, this is not the case! It is crucial in which form the protein is present, because not all Protein structures can be easily digested by our body. This is called bioavailability and this is better or worse depending on the food:

Animal protein sources and protein bioavailability

The spatial structure of the Protein sources plays an important role: tendons, bones and cartilage in meat are so strongly interconnected that they are difficult for the gastrointestinal tract to break down 4 . This makes it more sensible to cook them for a long time so that, for example, the valuable structural protein collagen from the resulting bone broth can be easily absorbed by the intestines. Tender and cooked or fried meat is easier to digest than raw meat. However, tartar is still a quality animal dish due to its finer structure. Protein source .

In itself, what is most similar to our own body is also what has the most important amino acids and is well absorbed. Accordingly, many animal sources have a high bioavailability and a higher protein content than plant sources. However, this does not necessarily mean that you cannot consume protein from plant sources. However, certain things should be taken into account.

Especially with For animal protein sources , particularly meat but also fish and eggs, the origin plays a further role: meat should be organically produced, ideally from pasture-fed animals with access to the outdoors, without antibiotics or genetically modified feed. Fish is best obtained from sustainable fishing. The smaller the fish, the better, because that also means a smaller food chain. Eggs have a much better nutritional content if they come from free-range chickens that move around a lot and are fed natural food.

Dairy products , especially from cows, are less optimal protein sources . Although they theoretically contain larger amounts of protein, they can promote inflammation in the intestine, which means that more inflammatory substances enter the body 2 . This also leads to the body digesting many things less well and thus generally having more difficulty digesting complex Proteins to record.

Plant protein sources

Legumes, for example, have a very strong structure and unfortunately also contain antinutrients that are actually there to protect the plant from pathogens. These inhibit some of our digestive enzymes and can thus prevent the absorption of micronutrients and the breakdown of the Proteins They should therefore always be soaked in water and lemon for 8 to 12 hours and then rinsed well before being boiled in fresh water. This process optimizes tolerance and bioavailability.

Soya is often considered to be the super plant- based protein source . Tofu is currently very popular with vegans. The bean does indeed have a very high Protein content , but it contains many of the antinutrients mentioned above, is usually contaminated with heavy metals due to washing in special tanks, can be genetically modified and also contains phytoestrogens. These are substances that act on our estrogen receptors and thus disrupt our hormone balance. If soy is still considered, the slightly better source would be tempeh, as this product is better tolerated due to the special fermentation process.

Seitan is one of the most problematic meat substitutes!
Industrially produced food consists largely of the Gluten is a protein that comes from grains, especially cheap wheat. Gluten is one of the main allergens that can damage our intestines and, especially in large quantities, triggers more and more intolerances. This plant-based protein source is therefore not a good option, because the proteins are very difficult for most people to digest and also trigger inflammatory processes.

Highly recommended plant-based protein sources are quinoa, buckwheat, millet and rice. However, it should not be forgotten that they also have a higher carbohydrate content. Quinoa actually provides all 8 essential amino acids and contains 14g per 100g protein but also 60g of carbohydrates. Meat has higher Protein values and contains no carbohydrates, which is why it is always a little harder to get rid of plant-based products. Protein requirements Nuts are similar, although they have a relatively high Protein content , but also contain a lot of fat, which is why they should only be consumed in small quantities, which then reduces the amount of protein per portion.

For vegans it is recommended Protein in powder form to take in. Rice, hemp or pea protein is very well tolerated and is filtered out of the respective products so that the carbohydrates are no longer present. Vegan-produced amino acids are important for the Protein requirements recommended.

How much protein do we need?

Depending on the source, different recommendations are given. The German Society for Nutrition says that at least 0.8g per kilogram of body weight should be consumed daily. However, new findings show that the body can cope with more protein Especially athletes and people who have more muscles or want to build them should consume 1.5 to 2g protein per kilogram of body weight. However, it is always important that the acid produced during the metabolism of protein is produced, can be neutralized by the body. Lots of vegetables help with this and calcium and vitamin D3 play another important role in the acid-base balance. This is because calcium neutralizes acid.


Protein sources are essential for our body. It needs the macronutrient Protein to carry out vital metabolic processes and to hold its components together. Therefore, enough protein should be consumed daily. The source plays an important role. Above all, animal protein sources have a high bioavailability, but also some plants such as quinoa, rice or nuts can help to Protein requirements cover up.

1 Doccheck Flexikon: Protein. [; 15.08.2020].

2 Nischwitz, Dr. Dominik (2018): Nutrition design according to Dr. Dominik Nischwitz.
The basis for your health. Tübingen: DNA Health & Aesthetics. Center for Biological Dentistry
Andreas Nischwitz Msc, Dr. Dominik Nischwitz.

3 Bütikofer, Markus; Hopf, Zensi; Rutz, Guido; Stach, Silke and Grigoleit, Andrea (2015): Human Biology 1: Basics, Metabolism and Defense Systems. Zurich: Compendio Educational Media.

4 Helmich, Ulrich (2020): Protein digestion. [; 15.08.2020].

Ines Schulz
Ines Maria Schulz, born on December 1st, 1992 in Basel, Switzerland, also completed her Master of Education in Biology and WAH there, laying the foundation for understanding physiology and anatomy as well as nutrition. She is also a trained primary school sports teacher. For two years she has been a coach at MTM Personal Training, the most successful personal training studio in Berlin. There she supports customers every day who want to exploit their maximum potential in terms of mental and physical health and performance. In cooperation with doctors such as Dr. Dominik Nischwitz and a laboratory for intestinal health as well as constant exchange within the team, she can give her customers optimal advice on training, nutrition, micronutrients and lifestyle. She has already written a breakfast book and a large part of a lifestyle booklet for MTM. She also writes the weekly newsletter, which publishes nutritional tips and recipes she has created. Ines has completed seminars and certificates with various successful coaches and specialists and is constantly expanding her skills. The young trainer has been writing blog articles for Supz Nutrition since January 2019.

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