Everything you need to know about proteins - why are they so important in your diet?

woman drinking a protein shake

What exactly is protein?

Proteins, alongside carbohydrates and fats are one of the three macronutrients. Proteins are chains of amino acids. There are twenty amino acids in total, of which nine are so called essential amino acids. Essential means that the body can’t produce them itself and instead must obtain them from its diet. In addition to that there are three semi-essential amino acids, which we only need to get from outside sources at particular times in our lives, for example as an infant or during an injury.

The non-essential amino acids can be created from the essential ones. Amino acids can be combined in various ways, resulting in tens of thousands of combinations. Each of the resulting combinations has an unique function. When we ingest food, it ends up in our intestine, where it is broken down into individual amino acids. The individual amino acids are then further processed in the liver and assigned their roles.

The biological value of protein

The essential amino acids should be at the focus of your diet. But how do you know which foods contain the essential amino acids?

There is a test for this. The test checks how many amino acids a particular food has and gives it a value out of 100. As a guideline, the chicken egg is deemed to have the ideal biological value and is therefore given a value of 100. As a rule, animal products tend to have a higher biological value than plant products, due to the similarities between animals and humans. Nevertheless, some plant products also have a high protein content and a high biological value. Examples of such foods are nuts and seeds. These are the only plant products to have a higher proportion of protein than carbohydrates. Other plant-based protein sources such as pulses or wheat, contain considerably more carbohydrates than protein.

Click here to learn more about the biological value.

Combining amino acids

We can and should combine foods in order to get a variety of amino acids and promote the biological value of a meal. An example of a food combination with a good biological value is eggs with potatoes. Just remember that potates contain only 1.5g protein per 100g so if you are trying to build muscle or lose weight then you should include a higher proportion of egg than potato in this combo.

Another combination is beef with potatoes. The meat should comprise 2/3 of the meal (this dish is a real protein source). As long as you are careful that the meat is not too fatty, meat and potatoes make an ideal meal. If you are on a diet, then choose beef fillets or chicken breasts over sausage meats and bacon. There are also combinations with a good biological value within a plant based diet. An example is a 50/50 mixture of beans and sweetcorn. To get a variety of different essential amino acids it is important to have a varied diet. (Tip: you can work out your optimal nutritional requirement with our BMI calculator). The following foods are important sources of animal and plant-based protein:

Top 10 Animal Protein Sources

Foods per 100g Protein in g Carbohydrates in g Fats in g Kcal
Beef Jerky 48 2,7 5,5 240
Harz cheese 30 0 0.7 126
Beef rump steak 28 0,3 12,6 229
Tuna 25 0 0,8 107
Turkey breast 24,6 0 1 107
Salmon fillet 23 0 7 159
Crab 18,6 0,7 1,4 91
Cottage cheese 13,3 3,3 1,4 81
Low-fat quark 13 4 0,2 75
Eggs 12 1 12 158

Top 10 Plant Protein Sources

Foods per 100g Protein in g Carbohydrates in g Fats in g Kcal
Spirulina (dried) 59,8 20,2 4,1 367
Sweet lupins 33 6,3 5,9 292
Soya beans 36 30 20 446
Sunflower seeds 26,1 34,7 26,3 590
Hemp seeds 33 12 44 587
Almonds 24 5,7 53 611
Chia seeds 17 42 31 486
Natto 17,7 1,8 11 176
Quinoa 14,7 62 4 355
Tofu 8,1 1,9 4,8 81

The role of protein in the body

Protein has many roles. The body uses it to build cells for example muscle-, hair- or skin cells. Our bodies’ antibodies are also made up of proteins. Proteins are required in every process of the body, since they form the enzymes required for metabolic processes. Broadly speaking, everything that happens in the body relies on there being enough protein available to form these enzymes.

In addition proteins can also serve as energy sources. In contrast to carbohydrates, there is no real storage area for proteins. The amino acid pool is constantly circulating as we are constantly building and breaking down cells. The real storage area is therefore anything that has been built from proteins, above all the basic musculature of the body.

How much protein should I eat?

In order to avoid muscle loss, the German Nutrition Institute recommends 0.8g of protein per Kg of body weight a day. If however, your goal is to build muscle, you should increase this to 2g per Kg of body weight. Amongst other things muscles are built from these proteins through a process called protein synthesis. The better condition you are in, the higher the level of protein synthesis, and the more protein you are able to metabolise.

How many calories you should consume, depends on your activity level, your training goal and the type of diet you follow. The proportion of these calories which should come from protein depends largely on your fitness goal. With a high protein diet it is important that you drink enough fluids because urea is produced as a by-product of protein consumption. The urea products travel via the kidneys and are excreted in the urine. It is important that the body has enough water to flush out these materials so that they don’t just build up in the body. You should make sure that your protein intake is spread across your meals. This avoids your kidneys becoming overly burdened with urea products and keeps your amino acid pool well stocked.

In general, we recommend a diet rich in protein, because only a small amount can be stored as fat or in the muscle glycogen. As a rule: in contrast to carbohydrates and fat, protein does not promote a rapid weight gain. It is scientifically proven that an increased supply of protein has a positive effect on muscle growth, hormones and health.

Summary of Proteins

Protein is made up of amino acids, the building blocks required for all important bodily functions. If you want to build muscle, and assuming you drink enough water, it is recommended that you consume 2g of protein a day for each Kg of body weight. Additionally seek out foods with a high biological value. The more essential amino acids you consume, the better for your body.

You want to learn more about the supplementation of protein? Click here to read everything about dietary supplements.

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