Protein is one of the three macronutrients that make up the food you eat (with the other two being fats and carbohydrates).
With this, I would argue that it is the most important macronutrient.
But why is this the case? And more importantly, how much do you need?
Why is protein important?
When you consume the protein molecules in food, they are broken down in your digestive tract into small compounds known as “amino acids” -- which are then absorbed into your body.
And this is important.
See, amino acids are commonly referred to as the building blocks of the human body [1].
They are used to make the hormones and enzymes found throughout your body, the neurotransmitters in your brain. They are also used to build and repair your tendons, organs, ligaments, skin and hair, and muscle tissue.
Now, it is important to note that there are a total of 20 amino acids found in your body -- but not all of them are created equal.
Eleven of these amino acids are considered “non-essential” because they can be made within your body. Considering this, the remaining 9 amino acids are known as “essential” because they cannot be made in your body, and therefore must be obtained through your diet.
This means that you need to eat a substantial amount of protein each day to optimise your health and function irrespective of whether you exercise, or not.
And if you actively weight train to get bigger and stronger, then this becomes even more important...
Every time you lift weights, you place your body under a significant amount of stress. This stress tells your body that it needs to adapt so it can better tolerate that stress in the future. It is this that causes your muscle tissue to grow bigger and stronger.
However, if you have insufficient protein available, then this growth cannot occur -- and you leave a lot of gains on the table.
Which begs the question: how much protein do you need on a daily basis?
How much protein do you need?
When it comes to protein intake, there is a little bit of contention between the Australian dietary guidelines and more recent research on the topic -- which can make finding clear recommendations somewhat difficult.
The most common recommendation you are likely to see comes from the Nutrient Reference Values for Australia and New Zealand, which were developed back in 2006 by a bunch of health professionals (mostly medical practitioners).
These guys set the recommended daily intake (RDI) of protein at:
- 64 grams per day for men aged between 19-70 years, and
- 46 grams per day for women aged between 19-70 years.
They also suggest that individuals aged above 70 years should increase their intake of protein by a further 25% to mitigate age-related loss of bone and muscle tissue.
But, I should note that these are the recommended daily intakes set by health professionals to ensure health and function -- and not to maximise muscle growth, which is another kettle of fish entirely.
In fact, if your goal is to build muscle and gain strength, I would argue that this is gross underestimation of how much protein you need to eat each day.
And the research supports this…
How much protein do you need to maximise muscle growth?
In my mind, if your goal is to build muscle, then there are two glaring issues associated with the above recommendations:
- They are simply too low to optimise muscle growth
- They are not based upon the individual.
It may seem a little obvious, but if you have someone who weighs 100kgs, and someone who weighs 60kgs, then there is a good chance that the heavier person will need more protein, no matter the circumstances.
And this is where recent research on the topic shines.
A meta analysis (a study that combines the results of multiple studies) of 49 studies found that the minimal threshold to maximise muscle growth when people perform resistance training is 1.6 grams of protein per kilogram of body weight, per day [1].
And I should note that this is the minimum amount to optimise muscle growth.
Additional research has suggested that going as high as 2.2 grams per kilogram of body weight may have further benefits [2] -- especially for people undertaking a cut, and are trying to maintain as much muscle as possible while maximising fat loss.
This means that if you weigh 70kgs, you should be eating somewhere between 112 and 154 grams of protein each day.
While this may sound on the high side, research has also shown that consuming as much as 3.3 grams of protein per kilogram of body weight does not have any adverse effects on health at all (yes, even kidney health) [3] -- indicating that you will be fine.
How often should you eat protein?
There is a common misconception in the fitness industry that you can only absorb 30 grams of protein at a time -- which is completely false.
However, when you eat a serving of protein, it increases “muscle protein synthesis”, which is the process your body uses to build new muscle tissue. Interestingly, 30 grams of protein appears to be enough to maximise your rate of muscle protein synthesis, which remains elevated for about 2-3 hours after eating [2].
This means that if you want to promote as much muscle growth as you possibly can, you might want to break up your daily protein intake into 4-5 servings throughout the day.
So, using the same 70kg individual above, a day of protein intake might look like this:
- Breakfast: 20 grams of protein
- Lunch: 30 grams of protein
- Pre workout snack: 20 grams of protein
- Post workout protein shake: 30 grams of protein
- Dinner: 30 grams of protein
All of which leads to a total intake of 130 grams, which sits smack bang in the middle of the 112-154 gram range we discussed above.
Best Sources of Protein
When you are looking for protein sources, there are a couple of boxes you want to tick when possible.
Firstly, you want to make sure that the food provides a substantial amount of protein per serving. Secondly, you want to make sure that the food provides all nine essential amino acids (and would be considered a “complete” protein source) [4].
Arguably the best sources of protein when adhering to these criteria are animal sources, including:
- Beef
- Eggs
- Chicken
- Poultry
- Seafood
- Milk
- Greek yoghurt
Although animal sources are generally considered the best source of protein, you can also obtain them from non-animal sources, such as:
- Quinoa
- Buckwheat
- Soy
- Quorn
- Oats
- Beans
- Lentils
You should also be aware that protein from vegetable sources are generally absorbed less readily than those derived from animal sources. While this is not a huge issue if you are eating enough protein, it is something that needs to be considered.
Finally, if you are after a simple complete source of protein that won't break the bank, it is hard to look past whey protein powder.
Whey protein is derived from dairy, and therefore contains all nine essential amino acids. It is also absorbed very quickly, making it the perfect option if you are looking for ways to increase your daily protein intake.
Final Message
If your goal is to build muscle and gain strength, then you probably need to be eating more protein.
In fact, striving for somewhere between 1.6 and 2.2 grams of protein per kilogram of body weight per day appears to be optimal for muscle growth. Moreover, you want to try and separate this into 4-5 servings throughout the day to boost muscle protein synthesis where possible.
No matter where you get your protein from, if you stick to these guidelines, you can be assured you are eating enough protein to meet your goals.
So what are you waiting for? It's time to chow down.
References
- Morton, Robert W., et al. "A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults." British journal of sports medicine 52.6 (2018): 376-384.
- Stokes, Tanner, et al. "Recent perspectives regarding the role of dietary protein for the promotion of muscle hypertrophy with resistance exercise training." Nutrients 10.2 (2018): 180.
- Antonio, Jose, et al. "A high protein diet has no harmful effects: a one-year crossover study in resistance-trained males." Journal of nutrition and metabolism 2016 (2016).
- Hoffman, Jay R., and Michael J. Falvo. "Protein–which is best?." Journal of sports science & medicine 3.3 (2004): 118.