Protein: Myths and Reality

Everything you need to know about protein.

Whenever I get a new client and they are a few days “in”, eating a healthy diet and experiencing what it feels like having a significant dose of protein with every meal, sooner or later I will get this question: “But isn’t eating so much protein bad?” I’m not sure where this fear stems from, but I blame the crappy fitness and health industry. No, it isn’t bad for you, quite the opposite is the case, it is healthy! Let me explain why.

The word protein comes from the Greek ‘proteios’, meaning ‘of first rank’, already indicating its importance. Proteins are responsible for most bodily functions and are found throughout the entire human body. They are your body’s worker bees. Over 40% of body protein is found in skeletal muscle, over 25% is found in body organs, and the rest resides mostly in the skin and blood. Check out Chantal’s article about protein for a quick reminder of what a protein is.

Functions of Protein

As already mentioned, proteins are of extremely high importance for your body, as almost every body function relies on them. A quick summary of the different roles of proteins:

  • Structural elements: Several proteins have structural roles in the body. They are effectively part of the bricks, mortar and steel that is your body’s house. We are talking of muscles, connective tissue, skin, hairs and so on…
  • Catalysts (a.k.a. Enzymes): Enzymes are proteins that speed up  chemical reactions and processes in the body. For example, in order to digest food you need enzymes.
  • Messengers: Certain proteins are hormones that act as messengers in the body to activate or deactivate other processes, think of insulin for example.
  • Buffers: Certain proteins act as buffers that regulate acidity levels of your blood and within cells. One prominent example is the hemoglobin found in red blood cells.
  • Fluid balancers: Certain proteins, such as albumin, act as fluid balancers that regulate water levels, keeping water in your cells.
  • Immuno-protectors and acute phase responders: Certain proteins are anti-bodies in your immune system that prevent you from getting seriously sick; other proteins have similar functions to keep you healthy when you do get unwell as well as repairing wounds.
  • Transporters: Certain proteins act as transporters, akin to tiny ships in your body that have nutrients, hormones or drugs as their cargo.
  • Other roles: Proteins carry out many additional roles in the body like cell adhesion and signal transmission in and out of the cells. In addition to their use in the synthesis of body proteins, amino acids are used to synthesize nitrogen-containing compounds that are not proteins but nonetheless play important roles in the body (like carnitine and creatine).

Essential amino acids

Amino acids are the building blocks of every protein and there are nine of them that are essential for the human body. Essential in this context means that the body is unable to produce them on its own and is completely reliant on constant intake of those essential amino acids from the food.

In other words: your life depends on eating enough essential amino acids!


As a strength trainee, you are interested in anabolism, the building process of your body. We want muscle tissue to grow and muscle consists mainly of protein, so we need sufficient protein intake.

Luckily protein intake is in itself a good signal for anabolism, so whenever we eat a meal that is rich in protein, we signal our body to grow, increasing protein synthesis acuetly.

Protein Myths

In the following I want to explore some common myths about the “overconsumption” of protein. Somehow protein got a bad reputation and as soon as “normal people” see somebody with serious protein intake, they are worried if this is good for his/her health.

Again, I’m not sure where this fear comes from. Nobody freaks out if you stuff yourself with bread and pasta, but as soon as you eat a whole chicken breast, people think your end is near. So let’s see why everybody needs to calm down.


You often hear that a high protein intake causes dehydration. In genereal it is true that a high protein intake causes a high water intake, however the overall inpact on hydration is only minimal. To back that up, we have research showing no signs of dehydration in men consuming 3,6g of protein per kg bodymass (that’s a lot!).

The dehydration myth seems to come from a study where dry rations for military personal were studied, showing a higher urine excretion with high protein rations. While this may prove useful in water restricted environments (like marshing through a desert), this isn’t of importance if you are able to drink as much water as you want.

Bone Health

Another popular protein myth is that protein is bad for your bones. The theory behind this belief states that sulfur-containing amino acids lead to acidification of the body and in order to neutralize this acidifying effect, calcium is removed from the bones. This is based on the observation that individuals on a high protein diet excrete more calcium in urine.

However, we now know that this acidifying effect isn’t detrimental to bone health, as your body is perfectly able to handle this on it’s own (as long as you follow some kind of healthy diet). The high calcium excretion can be easily explained by the effect that protein facilitates calcium uptake from your diet in the first place. Therefore your body has to get rid of the increased calcium in your body again, increasing calcium excretion.

Liver and Kidney Toxicity

Thirty years ago a scientist established an hypothesis that increased glomerular filtration rate (GFR) due to increased protein intake can lead to liver and kidney damage. GFR is a measure of how fast your kidney can eliminate waste products and the theory stated that a high GFR leads to higher pressure inside the organ, increasing the risk of damaging it.

Nowadays we have research showing that no organ damage is caused by high protein diets, even with very high protein intake (over 2,5g per kg bodyweight) over an entire year. Most experts agree that the higher GFR is just an adaptation of the body and is entirely physiological (not harmful in any way). GFR also increases during pregnancy, and as we know, being pregnant is not unhealthy in any regard.


There’s nothing inherently wrong or unhealthy about consuming more protein than your body can use to build muscle. The excess will simply be used as energy. Even highly excessive protein intakes consumed for months on end generally do not affect your health negatively and that includes your kidney health.

Proteins have a wide array of functions in your body and we need to consume them regulary to prevent catabolism, the state where your body “eats up” its own muscle mass to sustain its need for protein. This is even more important if you are in a calorie deficit! Live a healthy lifestyle, drink plenty of water, eat a balanced diet and enjoy your steak as often as you like 😉 .

Do you know of any other protein myths? Please let me know, comment down in the comment section!

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