Everything You Need to Know About Protein: The Building Block of Life - Coach Mark Carroll

Everything You Need to Know About Protein: The Building Block of Life

Aug 22, 2023
Roger Sutherland

In this blog by guest author Roger Sutherland – Shift Work Health & Wellbeing Coach, learn why protein is such an important macronutrient for health and muscle building and how to include it in your diet.


The first vision that comes to mind when we think about protein is a bulked-up gym “bro” strutting around the gym in a stringer singlet drinking from a shaker.  However, including protein sources in a daily diet is so much more than that for many health reasons.

Protein is an essential macronutrient that plays a crucial role in the proper functioning of our bodies. From repairing tissues to supporting muscle retention, and growth and maintaining a robust immune system, protein is often referred to as the “building block of life.” 

In this comprehensive blog, we will explore the importance of protein, the optimal daily intake, muscle protein breakdown and synthesis, and the differences between plant and animal protein sources. 

Whether you’re an athlete looking to maximize muscle gains or someone simply curious about their nutritional needs, this guide will provide you with valuable insights on all things protein.

What is Protein?

Protein is one of the 3 Macronutrients (MACROs) with the other 2 being Carbohydrates and Fats.

Our body needs these macronutrients in sufficient quantities in order to function properly.

These three macronutrients provide energy to the body.

Protein contains 4kcal per gram (carbohydrates 4kcal per gram and fats 9kcal per gram)

Protein is a complex molecule made up of amino acids, which are the basic units that join together to form various proteins. Think of amino acids as building blocks, and proteins as the intricate structures they create. 

Think of Lego blocks as the amino acids, and what they form when stuck together as the proteins.

These proteins are involved in countless biological processes, making them essential for our survival and overall well-being.

Our body does not store amino acids, so it must make them from scratch from the foods we eat.

There are 20 Amino Acids in total. 

  • Essential Amino Acids
  • Nonessential Amino Acids
  • Conditional Amino Acids

Essential amino acids (EAAs)

Cannot be made by our body, so we must get them from food.

    • Lysine
    • Tryptophan
    • Threonine
    • Methionine
    • Phenylalanine
    • Histidine
    • Leucine*
    • Isoleucine*
    • Valine*

*Branch Chain Amino Acids (BCAAs)

BCAAs play a crucial role in protein synthesis and muscle metabolism

  • Leucine: Leucine is considered the most critical BCAA for muscle protein synthesis. It activates the mTOR (mammalian target of rapamycin) pathway, which stimulates the creation of new muscle proteins and helps with muscle repair and growth. It also aids in regulating blood sugar levels and promoting wound healing.
  • Isoleucine: Isoleucine is involved in energy regulation, immune function, and haemoglobin synthesis. It can also enhance glucose uptake into cells, providing an additional energy source during physical activity.
  • Valine: Valine helps maintain proper nitrogen balance in the body and is involved in muscle metabolism. It can also act as a source of energy during intense exercise.

Do we need to supplement BCAA’s 

Supplementing BCAA’s is very popular, but is it necessary?

While BCAAs offer benefits for muscle health and exercise performance, it’s essential to note that a balanced diet that includes a variety of protein sources generally provides adequate amounts of BCAAs for most people.

Supplementing with BCAAs is generally unnecessary and really is just like watering your lawn with a sprinkler while it’s raining.  Such a waste of your hard-earned money.

BCAA’s for Vegans and/or Vegetarians

Whether a vegan or vegetarian should supplement BCAAs depends on their individual dietary habits, exercise routine, and health goals. In general, people who follow a well-balanced plant-based diet can obtain sufficient BCAAs from various plant sources. However, certain circumstances might warrant BCAA supplementation:

Protein Intake: Vegans and vegetarians who struggle to consume an adequate amount of protein through their diet might consider BCAA supplementation. BCAAs are essential for muscle protein synthesis and recovery, especially for individuals engaged in intense physical activities or strength training.

Intense Exercise: If someone follows a plant-based diet and engages in high-intensity or prolonged exercise, BCAA supplementation might be beneficial for supporting muscle repair and reducing exercise-induced muscle breakdown.

Low Leucine Levels: Leucine is the most critical BCAA for muscle protein synthesis. Some plant-based protein sources may have lower leucine content compared to animal-based proteins. In such cases, a targeted leucine supplement might be considered to ensure sufficient intake.

It’s essential to note that whole-food, plant-based protein sources can provide all the essential amino acids, including BCAAs. Foods such as legumes (beans, lentils, chickpeas), tofu, tempeh, seitan, quinoa, nuts, and seeds are rich sources of protein and can contribute to BCAA intake.

Conditionally Non-Essential

(Newborn babies and and people with diseased livers do not synthesise these)

  • Cystine
  • Glutamine
  • Proline
  • Tyrosine
  • Arginine
  • Glycine


  • Alanine
  • Asparagine
  • Serine
  • Aspartate
  • Glutamate

Consuming a diet rich in Protein means you will be getting enough essential amino acids.   These proteins are available in both animal and plant-based foods.

Some foods contain “complete” proteins, and this means that they contain all 9 essential amino acids in adequate amounts.

Complete protein-containing sources include.

  • Red Meat
  • Poultry
  • Fish
  • Seafoods
  • Milk
  • Eggs
  • Cheese
  • Yoghurt
  • Chia Seeds
  • Quinoa
  • Tofu

Why is Protein Important?

Never, ever underestimate or underrate the value of protein in your everyday intake.

Protein serves a multitude of vital functions in the body. Firstly, it is crucial for tissue repair and growth. When we engage in physical activities, our muscles undergo wear and tear, and protein helps to rebuild and strengthen them. Additionally, proteins are responsible for enzymatic reactions, hormone production, and transportation of nutrients and oxygen throughout the body. Proteins also play a significant role in maintaining healthy skin, hair, and nails.

Proteins are essential macromolecules that play a vital role in the structure, function, and regulation of almost all aspects of living organisms. They are made up of long chains of amino acids and are involved in various biological processes. 

Protein is also known as the satiety macronutrient as increasing protein in your diet reduces hunger.   

We burn more calories digesting protein than we do carbohydrates or fats.

Let’s look at some of the reasons why proteins are crucial for life in detail:

Structural Support: Proteins serve as the building blocks of tissues, muscles, organs, and cells. Collagen, for instance, is a structural protein that gives strength and flexibility to connective tissues like tendons, ligaments, and skin.

Enzymes: Many proteins act as enzymes, which are biological catalysts that facilitate and speed up chemical reactions within the body. Enzymes are involved in digestion, metabolism, DNA replication, and almost every other biochemical process that sustains life.

Transport and Storage: Some proteins transport molecules like oxygen (e.g., haemoglobin in red blood cells), ions, and nutrients throughout the body. Others store essential substances like iron or provide a reservoir of amino acids for the body to draw upon when needed.

Hormones: Certain proteins function as hormones, acting as chemical messengers that regulate various physiological processes. For example, insulin is a protein hormone that helps control blood sugar levels.

Immune Function: Antibodies are specialised proteins produced by the immune system to recognize and neutralize foreign invaders, such as bacteria, viruses, and other pathogens.

Cellular Signalling: Signalling proteins transmit information within and between cells, regulating processes like cell growth, differentiation, and apoptosis (programmed cell death).

Muscle Contraction: Proteins like actin and myosin are essential for muscle contraction, enabling movement and bodily functions.

Cell Adhesion: Proteins are crucial for cell adhesion, allowing cells to stick together and form tissues and organs.

Gene Expression: Some proteins are involved in regulating gene expression, controlling when and how certain genes are turned on or off.

Energy Source: In times of energy deprivation, the body can break down proteins into amino acids and convert them into energy.  This is called gluconeogenesis, but our body is not efficient at it hence why we can feel very average when on a low-carb diet.

Overall, proteins are the workhorses of the body, carrying out a wide range of functions necessary for the growth, repair, and maintenance of tissues and organs. 

A well-balanced diet that includes an adequate amount of protein is crucial for maintaining overall health and supporting these essential biological processes.

As you can now see, insufficient protein in our diet will severely impact our health.

What is the Optimal Amount of Protein We Should Consume Daily?

Protein is not only for our gym friends who want to build muscle.

Inadequate protein compromises our immune function, causes sarcopenia (progressive age-related loss of muscle and strength) which increases a fall risk and also inhibits recovery from immobilisation (e.g.: post-surgery)

Next time Nanna is hospitalised, take her a protein shake, not a box of chocolates.  She’ll recover a lot quicker.

The optimal amount of protein a person should consume daily can vary based on various factors.  Factors to consider are age, sex, activity level, and individual goals (e.g., building muscle, weight loss, general health maintenance). There isn’t a one-size-fits-all answer, but I can provide you with some general guidelines.

The Recommended Dietary Intake (RDI) for protein intake is 0.8 grams of protein per kilogram of body weight per day for adults. This means that a sedentary adult who weighs 70 kilograms (154 pounds) would need about 56 grams of protein per day. However, research studies suggest that higher protein intake might be beneficial for certain populations:

Active Individuals: People who engage in regular physical activity, especially strength training or endurance exercises, may benefit from higher protein intake to support muscle repair and growth. For active individuals, protein intake in the range of 1.6 to 2.5 grams of protein per kilogram of body weight per day might be more appropriate.

Weight Loss: When trying to lose weight, a higher protein intake can help with satiety and muscle preservation. In this case, protein intake in the range of 1.6 to 2.5 grams of protein per kilogram of body weight per day might be useful. The higher end of the range is more suitable for someone who is very lean when in a calorie deficit, and the lower end of the range is for someone who has high body fat.

Older Adults: Older adults may also require slightly higher protein intake to prevent age-related muscle loss. Protein intake in the range of 1.6 to 2.5 grams of protein per kilogram of body weight per day could be beneficial for this group who are also active.

Athletes: Athletes, particularly those in endurance or strength-based sports, might need even higher protein intakes, potentially in the range of 1.6 to 2.7 grams of protein per kilogram of body weight per day, depending on the sport and intensity of training. (Phillips & Van Loon, 2011)

So why is the RDI so low?    This is because the RDI is the absolute bottom level before being severely deficient and your health suffers.

Excessive protein intake isn’t necessarily more beneficial, but it is essential to consider the quality of protein sources. Lean meats, poultry, fish, eggs, dairy products, soy, legumes, nuts, and seeds are good sources of protein.

It is also important to add here that, if you have two normal functioning kidneys, over time your body will digest all protein consumed.   This debunks the myth that you can overconsume protein.

Individuals with specific health conditions or those with unique dietary needs might require personalised recommendations. If you’re unsure about the right amount of protein for your situation, it’s a good idea to consult with a registered dietitian or a physician who can provide personalised guidance based on your individual needs and goals.

If you’d like to learn your protein and calorie requirements please use our Free TDEE Calculator.

Muscle Protein Breakdown (MPB) Vs. Muscle Protein Synthesis (MPS)

It should not only be our goal to maintain or build muscle through muscle protein synthesis (MPS) but the key is to prevent muscle protein (MPB) breakdown as much as possible.

To explain further, let’s break both of these down and look at them in detail.

What is Muscle Protein Breakdown, and How Do We Prevent It?

Muscle protein breakdown is a natural process that occurs during exercise, particularly in resistance training. It involves the breakdown of muscle protein to release amino acids for energy. While some level of protein breakdown is normal, excessive breakdown can hinder muscle recovery and growth. Let’s explore some strategies to prevent muscle protein breakdown and promote optimal muscle repair.

Optimise Protein Intake: Regularly consuming an adequate amount of high-quality protein is essential. Include sources like lean meats, poultry, fish, eggs, dairy, legumes, and plant-based protein sources. Protein provides the necessary amino acids for muscle repair and growth.

Strategic Meal Timing: Fasting for extended periods is less than optimal to prevent muscle protein breakdown, which can impact muscle health. If we plan our meals and snacks to ensure a consistent intake of protein and Include protein-rich snacks, this will provide a steady supply of amino acids.

Consuming protein every 3-5 hours ensures a continuous supply of amino acids in the bloodstream, stimulating muscle protein synthesis, which prevents the breakdown of muscle.

Prioritise Sleep: Poor and insufficient sleep will contribute to MPB. Focus on creating a conducive sleep environment, including a cool, dark and quiet room. Develop a consistent sleep schedule, even on non-working days, to regulate circadian rhythms.

Hydration: Dehydration can affect muscle function and recovery. Stay adequately hydrated by consuming water.

Manage Stress: Chronic stress triggers the release of cortisol, a hormone that can promote muscle breakdown. Incorporate stress management techniques such as deep breathing, mindfulness and lighter less stressful exercises.

Exercise: Engage in regular physical activity that includes both resistance training and cardiovascular exercises. Resistance training helps maintain muscle mass, while cardio supports overall cardiovascular health.

Supplementation: Always consult a healthcare professional before considering any supplements. 

At Coach Mark Carroll we do not consider protein powder as a supplement.  It is a very beneficial food that can assist with protein intake in your day.

Monitor Progress: Watch your energy levels, muscle soreness, and overall well-being. Adjust your nutrition and lifestyle strategies based on how your body is feeling.

Preventing Muscle Protein Breakdown is a multi-pronged approach, that combines proper nutrition, sleep management, stress reduction, and physical activity. By implementing these evidence-based strategies, you will be doing your best to prevent muscle protein breakdown.

What is Muscle Protein Synthesis?

We have addressed preventing muscle breakdown, which is essential, so let’s now look at the optimal way to increase lean tissue.

Muscle protein synthesis is the process of building and repairing muscle tissues. This occurs when the rate of protein synthesis is higher than the rate of breakdown.   This results in muscle growth and adaptation. 

We will discuss how factors like exercise, diet, and timing can influence muscle protein synthesis.

Exercise: Regular physical activity, especially resistance training, is a key player in stimulating MPS. Engaging in well-rounded exercise routines that include both strength and endurance training, not only supports overall fitness but also boosts MPS, aiding muscle growth.

Diet:  Nutrition is the key.   Adequate protein intake is paramount for MPS. We must prioritise high-quality protein sources like lean meats, fish, eggs, dairy, legumes, and plant-based proteins such as soy. While individual needs vary, a general guideline is around 1.6 to 2.5 grams of protein per kilogram of body weight per day for muscle protein synthesis.

Timing: The timing of protein intake around training can impact MPS. Ensuring you are consuming protein-rich meals or snacks every 3-5 hours assists with MPS. The protein post-training capitalises on the heightened sensitivity of muscles to protein-induced growth.

No, you do not need to whoop down a protein shake as soon as you finish your last rep.

The evidence supports every 3-5 hours regardless of when you trained.  However, if you did not consume protein prior to training then a whey protein shake would be beneficial immediately after.

If you’d like to learn more about pre-workout nutrition and meal ideas please download our Free Workout Nutrition Guide.

Sleep: Sleep is critical.  Sleep deprivation can disrupt hormone levels, including those related to MPS. Optimise sleep hygiene and create a conducive sleep environment.

Hydration: Often overlooked, hydration plays a role in MPS too. I encourage adequate water intake throughout the day, as dehydration can impair protein synthesis and muscle function.

How much is enough?  Clear or straw-coloured urine = sufficiently hydrated.

Stress Management: Chronic stress elevates cortisol levels, which can hinder MPS. Incorporating mindfulness, meditation, or relaxation techniques can support both mental and physical wellness.

Consistency: Consistency is the name of the game. Progress takes time. I encourage you to adhere to an exercise routine and nutrition habits consistently to see meaningful results in MPS and overall well-being.

It takes a lot longer to build muscle than it does to lose body fat, so the key is to stay consistent and be patient.

If Wanting to Build Muscle, How Often Should We Consume Protein?

If you are looking to optimise building muscle, protein consumption becomes even more critical. Not only the quantity but also the distribution of protein intake throughout the day plays a significant role in supporting muscle growth. We will explore the concept of protein timing and the benefits of spreading protein intake across meals.

So far we have covered protein requirements, preventing muscle breakdown and stimulating muscle protein synthesis, but all you want to do is build some serious muscle, right?  So how often should we consume protein and how much?

As has been flagged previously, the key is to ensure you are getting a complete protein source every 3-5 hours if you want to optimise muscle growth. (Prevent breakdown)

But what’s the best way to go about this?

I will demonstrate using an example of a client that weighs 65kg (143lbs)

Protein Shake 0.3g Protein per kilogram of body weight (19.5g Protein)

Mixed Meal (P/C/F) 0.5g Protein per kilogram of body weight (32.5g Protein)

Before Bed 0.6g Protein per kilogram of body weight (39g Protein)

We use this amount to ensure that there is sufficient Leucine, the amino acid that stimulates MPS, at each feeding of protein.

It is vital to check the amino acid profile of your protein powder of choice (whey or plant).

Ensure that each serve (not per 100g) is a minimum of 2.4g of the branch chain amino acid leucine.

This can be found on the nutrition label or the manufacturer’s website.

Is Plant Protein Equal to Animal Protein?

The debate between plant-based and animal-based proteins is a common one. Both sources contain protein but offer different amino acid profiles and come with their unique benefits.

Generally, animal proteins are complete proteins, which means they contain all 9 of the essential amino acids in adequate amounts.

When it comes to plant proteins, only a few are considered complete proteins on their own and most are very low in some essential amino acids.

What this means is that the majority of plants, while they contain protein, are missing 1 or more of the essential amino acids.

All is not lost though; a well-balanced and diverse plant diet ensures that all amino acids can be covered to form a complete amino acid pool.

Examples of this, are a peanut butter sandwich or beans and rice.

While bread and peanut butter are not complete proteins on their own, when consumed together they form a complete protein.   Beans and rice are the same.

To settle a time-honoured argument.  The current evidence reports that if equated, plant proteins are equal to animal proteins.

Great Sources of Animal Protein

  • Animal-based protein sources provide a rich and complete amino acid profile. 
  • Poultry, Seafood and Fish
  • Dairy Foods including yoghurt, milk, cheese
  • Red Meat should be limited and consumed in small amounts and with a good serving of vegetables.
  • Processed meats, while animal, should be avoided

Great Sources of Plant Protein

Plant-based protein sources are abundant and offer various health benefits, such as being lower in saturated fats and cholesterol, with plants also being high in fibre.

When it comes to health, it could be argued to get your protein from plants where possible.

It’s important to ensure that you mix sources to make sure no “essential” amino acids are missing and are available in adequate amounts.  This takes some education.

Legumes: Lentils, edamame/soybeans(tofu, tempeh, etc.) peas (green, snow, snap, split etc.) beans

Nuts and seeds: Flax, pumpkin, sunflower, cashews, hemp, pistachios, chia

Whole grains: Wheat, quinoa, rice, wild rice, oats, buckwheat.


Protein is undeniably one of the most crucial nutrients for human health and vitality. From supporting muscle growth to aiding in the repair of tissues, it is a vital component of a well-balanced diet. By understanding the importance of protein, its optimal daily intake, muscle protein breakdown, and synthesis, and the diversity of both animal and plant-based protein sources, you can make informed decisions to improve your overall health and well-being. Remember, it’s not just about the quantity of protein you consume, but also the quality and balance that matters most.

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Roger Sutherland

A Healthy Shift