The Role of Protein in The Human Body

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You would have to be living in a cave to have not heard or read anything about the importance of protein as a human. New studies are coming out regularly confirming this theory as fact. 

But what does that actually mean, and why is protein so important?

The Three Macronutrients

Firstly let’s understand the role of the other two macronutrients, carbohydrates and fats. These macronutrients are used primarily as fuel for the body, specifically carbohydrates which is the only non-essential macronutrient. These are converted into ATP which produces the energy required for the body to move around.

Protein can be used for that if absolutely necessary, but is not its primary role. 

The Primary Role of Protein

The role of protein is to be broken down into its constituent amino acids via the digestive tract, and then for those amino acids to enter the bloodstream. Once they are in the bloodstream, they are not prioritised as fuel like carbohydrates and fats. They are prioritised to rebuild the proteins in your body. 

Proteins are found in everything from your skin to your hair, to your vital organs and muscles.

However, if you are not eating enough food and living in a caloric deficit, your body will actually convert more of the protein into an energy source instead. This is because your body in a caloric deficit is focused on survival, breaking down your muscle tissue to be used for energy.

This is a mistake many people make when trying to lose weight or stay lean. They keep themselves in such a high caloric deficit, that any protein eaten is not doing its primary role to restore tissue.

Being in a maintenance or slight caloric surplus is the best place to be, as the foods you eat will be used for their primary purpose helping you build and retain muscle tissue.

Thermic Effect of Food

There is another minor issue to consider about protein, and that’s the amount of energy required to break down the constituent parts of the foods. This is why the caloric effects of protein vs carbohydrates are different. Even though 1 gram of either is equal to 4 calories. In actual fact, because the process to break down and use protein is more energy consuming, effectively the ultimate calories absorbed by eating protein is less than carbohydrates.

Best Sources of Protein

There are 9 essential amino acids required from protein for your body to function optimally. Food that includes all 9 essential amino acids are called “complete proteins”. Complete proteins are found in:

Animal Sources

  • Meat (beef, pork, lamb etc)
  • Poultry (chicken, duck, turkey etc)
  • Fish
  • Eggs
  • Dairy products (whey, milk, yoghurt, cheese etc)

Plant Sources

  • Quinoa
  • Tofu
  • Edamame
  • Hemp seeds
  • Chia seeds

One of the major differences between animal and plant protein is the amount of available protein in comparison to the amount of food.

As an example, there is approximately 60 grams of protein in a 250 gram beef tenderloin. Whereas to get the same 60 grams of protein from quinoa, you would need to eat 1kg. I love quinoa, it’s a great food source. But try eating 1kg of it and you will soon become quite bored with a very tired jaw.

These comparisons are similar throughout the animal vs plant protein debate world. Which is why animal protein sources are considered superior, and the main reason why it is not easy to ingest enough essential amino acids from food protein sources on a vegan diet.


There are many resources throughout the podcasts I listen to on the importance of protein. But in The Genius Life #369 Max talks to Angelo Keely, the co-founder of the Kion supplement company whom I buy my Essential Amino Acids from, as well as Omega Fish Oils, Flex joint support, and creatine supplements. I also love their dark roast organic pesticide free coffee.

Their discussion dives deep into the scientific reasons behind the importance of protein and amino acids, how they affect your energy and longevity, and why you need to focus on protein as your number one most important food source. 

Dig in to continue your self education process to discover how you can use essential amino acids to Live Stronger & Live Longer!

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