Protein - what’s all the fuss about?

Why is everyone always banging on about protein?

I used to wonder what the big deal was about protein. I assumed protein would just help me build muscle. But it wasn’t until I began studying for my PT qualification that I began to realise the extent of just how important protein really is.

I’ve tried to simplify this as best I can, so bear with me whilst I get into this…

“Building blocks of life…”

Protein is one of three macronutrients (the other two being fats and carbohydrates), and arguably the most important. Why? Well, because protein is the only macronutrient to contain nitrogen, without which we cannot grow or reproduce.

My NASM textbook explains it a little better than me:

“Proteins are the building blocks of life. The body needs protein to repair and maintain itself. Every cell in the human body contains protein. It is a chief component of the skin, muscles, organs and glands. Protein is also found in all body fluids, except bile and urine. Protein is needed in the diet to help the body repair cells and make new ones.” ¹

How much protein do I need?

Whilst protein is essential for human life, more isn’t necessarily better. If you consume too much, like anything, your body may store the excess as fat.

But the exact amount we need to eat is still widely contested today.

The Dietary Guidelines for Americans recommend the following daily amounts² of protein for different age groups:

Children under 4: 13 grams

Children ages 4 to 8: 19 grams

Children ages 9 to 13: 34 grams

Women and girls ages 14 and over: 46 grams

Boys ages 14 to 18: 52 grams

Men ages 19 and over: 56 grams

However, the National Academy of Sports Medicine (NASM) argue:

“The amount of protein required for effective function will vary significantly from person to person. It’s very difficult to get it right with a simple calculation, and it takes some trial and error and fine-tuning to find what works best for an individual.”

“In the UK it is often the case that the only decent amount of protein eaten during the day is in the evening meal. Protein should be a major part of every meal consumed. A basic starting point to work out how much protein an individual needs is to consider body weight and physical activity levels. Table 1.5 provides some suggested intakes (set by the American College of Sports Medicine (ACSM)) of grams of protein per day dependent on an individual’s activity type and levels.” ³

For the average sedentary adult, they recommend 0.8 grams of protein per kilogram of bodyweight. But for adults seeking muscular hypertrophy (to build muscle size), like me, the recommended intake is almost doubled to 1.5 - 1.7 grams of protein per kilogram.

That’s quite a lot of protein to consume in just one day! For me to get at least 1.5 grams of protein per kg of bodyweight means I need to eat around 99 grams a day. Looking at my calorie tracker today, I’ve only consumed 47 grams and that has been a push!

Above: My afternoon snack today. Not the healthiest way to get my grams in, but I find protein bars and shakes are a quick and convenient way to boost my protein intake.

As NASM state above, the exact amount each person will need is likely difficult to pin point. For sedentary adults, as long as they’re getting the minimum recommended amount, it’s less of a concern. However if you’re training regularly, you will need additional protein in order to repair and regrow muscle, as muscle catabolism occurs during intensive exercise - as a result of both micro-tear damage and the partial utilisation of key amino acids as fuel. To repair, regenerate and grow, you'll need sufficient protein intake.

Now, what was that about amino acids...

The 9 essential amino acids…

All proteins are made from organic compounds (think of them like building blocks) called amino acids, and there are 20 amino acids in total. However, only 9 of these amino acids are considered essential to human life, purely because the body is unable to produce or synthesise them itself - we can only get them from food. Without those 9 amino acids, we could grow neither healthy hair, skin and nails, nor strong bones and muscle, and our immune systems would be impaired.

Amino acids can be found in two types of proteins: complete and incomplete.

Complete proteins contain all nine essential amino acids and can be found in meat, fish, poultry, eggs, soy and dairy products. Some experts claim that there are a number of plant-based complete proteins, but the density of essential amino acids is generally higher in animal-based proteins.

Incomplete proteins can be found in cereals, legumes, fruits and vegetables. Plants also contain protein, however these proteins are considered to have a lower biological value since they are usually lacking one or more of the essential amino acids. Plants also generally contain smaller concentrations of protein, making it difficult to ingest enough solely from plant produce.⁴

Whilst it’ll certainly be easier to ingest your recommended complete protein intake if you’re omnivorous, and whilst the density of amino acids is higher in animal-based proteins, NASM state that “we do not have to eat animal products to get all the protein our bodies require”.⁵

Protein requirements can be met by consuming complete, incomplete and complementary proteins. For many years nutritionists have advised vegetarians to vary or combine plant-based protein sources to boost amino acid intake. This may help to provide a full spectrum of the essential amino acids in the diet.

Something to keep in mind for the next heated plant-based VS omnivore debate. You can get all of the protein and amino acids you need following a plant-based diet that encompasses a variety of plant-based foods. It just might be easier if you’re an omnivore.

I could go on…

This blog is already too long and there is still so much I have yet to cover! But I think this is a good starter to cover the fundamentals of protein and why our bodies need it, guidelines for how much protein we need, and how to get the nine essential amino acids.

I’ll leave it for now, but I’m interested in covering some other related topics soon including protein as a tool for weight loss, using it to beat age related muscle loss (sarcopenia), and more. Stay tuned.

Sayonara!

Ari

References:

1. p62. Level 3 Certificate in Personal Training, Active IQ. 2017.

2. https://www.webmd.com/diet/benefits-protein#1. 2021.

3. p66. Level 3 Certificate in Personal Training, Active IQ. 2017.

4. p64. Level 3 Certificate in Personal Training, Active IQ. 2017.

5. Kris Gunnars, The Truth About High Protein Diets and Kidney Damage, 2013.

6. p63. Level 3 Certificate in Personal Training, Active IQ. 2017.