How Much Protein Do You Need?

Protein is required for the restoration, repair and growth of bodily tissues. For the purpose of this article we're mainly interested in Skeletal Muscle and protein's effects on Lean Body Mass (LBM).

Protein's are made from Amino Acids, also known as peptides. Two peptides together are called a dipeptide, three together are a tri-peptide and four or more are referred to as polypeptides.

There are 20 different amino acids (AA) within the foods we eat, that are referred to as either essential or inessential:

Essential means that the body cannot produce them itself and must acquire them through the diet. In contrast, the inessential amino acids can be synthesised from the other amino acids and so they don't need to be consumed within the diet (that is not to say that there isn't a benefit to them, it's just to say that you won't die)

At this point I'd like to state that unlike carbohydrate and fat, protein isn't effectively stored within the body for later use:

A 70kg human being with 20% body fat has 14kg of fat mass, the equivalent of around 108,000 stored calories ready to go, and as a bonus we have the ability to create new fat cells if we fill our current ones. Fat is an essentially limitless storage deposit. 

The average human has between 1200-2000 calories of Muscle Glycogen (stored carbohydrate) plus about another 440 calories of Liver Glycogen. Combined this is around 410g to 610 grams of stored available carbohydrate.

Proteins are a little different; they have a couple of options. 

  1. Use them to create new tissues and drive various bodily functions
  2. Break them down and excrete them.

The body maintains a small reserve of amino acids in storage that we call The Free Amino Acid Pool.

To quote Lyle McDonald, in his excellently titled and just generally excellent, The Protein Book:

"The free AA pool is relatively small, comprising roughly 1% of the total protein stored in the body. In an average 70 kg (154 lb) man, body protein may comprise 10 kg (22 lbs) of AAs; however, the free pool has been estimated to contain only 100 grams of AAs, not including taurine. Only 5 grams of AAs are actually present in the bloodstream. If taurine is included, the size of the free pool increases to 130 grams of AAs" 

The body maintains the Free AA Pool through the intake of dietary proteins and through the breakdown of existing tissue. As such not eating enough protein, or potentially not eating protein often enough, may lead to the loss of LBM. This is due to the body's attempt to maintain it's AA pool through the increased breakdown of existing proteins rather than adequate dietary intake.


Imagine you are attempting to put an extension on your kitchen. Here your skeleton represents your plot of land and sadly there is no more land for sale (at least not without some drastic bone surgery).

You want to make a bigger house (because no one wants to downsize their muscle duh) and so the only way of making a bigger house (growing more muscle) is by knocking down the existing kitchen wall (breaking down muscle tissue, through the use of appropriate training) and building an extension. 

What would happen if I knocked down the wall but forgot to order more bricks?

I can't build an extension without getting a delivery of the materials required to do so; instead I'm just smashing walls (kind of fun) but getting nowhere. As a result I either have to tear down another part of the house to rebuild the wall I've just destroyed (more protein breakdown) or I'm left with a gaping hole in the kitchen (making no progress).

As I think I heard Eric Helms say once and will now happily steal, "Nutrition is Permissive to Growth".

Training adaptations will not occur all that well if we don't fuel them. Remember that you get bigger, faster, fitter, stronger etc, after training not during it.


As an aside we often see the opposite thought when people are attempting to bulk a.k.a If I just eat more I will grow more. Sadly, you cannot force feed muscle growth. There is a finite rate at which muscle can grow and eating more than this just leads to unnecessary fat gain. If simply eating more led to muscle growth we'd have a bodybuilding epidemic rather than an obesity one.

So to the age old question of which is more important, diet or exercise, I would say this:

  1. Without training, nutrition isn't used effectively
  2. Without nutrition, we can't adapt to the training effectively

In other words you need both. This is not me saying that there isn't a hierarchy of importance here either; there is. But neither works as effectively without the other.

Factors Affecting Protein Requirements

Protein needs increase under two conditions that matter when trying to look great naked:

  1. Dieting
  2. Weight Training

Though it might seem counter intuitive, we actually have a higher need for protein when dieting than when trying to put on muscle. The reason is pretty straight forward; when dieting you are, by definition, not getting enough energy to sustain your body's day-to-day needs. As a result some of the protein that is normally available for growth and repair is used for energy, leaving less available for our precious muscle tissue.

Weight Training also creates a greater demand for protein, as a result of recovery and attempting to build more muscle tissue. However this is contingent on a few things from a training perspective (which we'll cover in more depth in a later article), but for now they are:

Volume (sets x reps x weight), Intensity (% of maximum) and Frequency

Everyone has helped lifted something really heavy, like a Fridge or a Sofa, which has a high level of Intensity (a.k.a it's bloody heavy) but you only did it once so you didn't get all jacked and sexy. Why? You needed more Volume

Equally if you were to curl a Coke can 1,000,000 times you're unlikely to have guns that would make Rambo blush. Why? Because although the Volume is high, the Intensity isn't enough.

And if you only did it once every 6 months, it's going to do nothing for you. Why? Because you had about as much Frequency as the Daily Mail issuing an apology; it basically never happened and if it did it was almost certainly by mistake.

Take Home Point - Higher Protein Intakes have a positive effect on LBM that are especially pronounced when dieting and weight training.

So hopefully I've now convinced you that the aim of a diet is Fat Loss not Weight Loss. If you're still not sure why I'm making that distinction, look up!

Those guy's sure as shit lost a boat load of weight but I'm going to go out on a limb and guess that that isn't the look you had in mind? 

Good. I'm glad you're with me on that. So when we talk about successful dieting we're really talking about achieving Fat Loss without Muscle Loss. When done really well, it looks something like this:

There are three factors you need to consider and master to ensure fat loss without lean body mass loss:

  1. Resistance Training
  2. Rate of Weight Loss
  3. Adequate Protein

Resistance Training will be the subject of it's own article in the near future but it's safe to say it's the most important factor affecting Muscle Mass.
The Rate of Loss can affect the amount of Fat Mass versus Lean Mass you lose while dieting. For more information, read here.
Adequate Protein; let's talk about how much you need and then where to get it from.

Set Protein Between 2.3-3.1g/kg/lbm/day



Gemma has 27% Body Fat at 69kg, meaning she has:
18.63kg of Fat Mass  
50.37kg of LBM
At the low end of 2.3 grams per kg/day she would have:
115g Protein per day
115 x 4 = 460 calories*
At the high end of 3.1 grams per kg/day she would have:
156g Protein per day
156 x 4 = 624 calories*


Tom has 15% Body Fat at 85kg, meaning he has:
12.75kg of Fat Mass
72.25kg of LBM
At the low end of 2.3 grams per kg/day he would have:
166g Protein per day
166 x 4 = 664 calories*

At the high end of 3.1 grams per kg/day he would have:
224g Protein per day
224 x 4 = 896 calories*

*We need to know the number of Calories from Protein per Day in order to work out how many we have left over for your Carbohydrate allowance.

How To Decide When To Use 2.3 - 3.1

I'm going to be a little annoying here and state that there aren't fixed rules governing when you must use 2.3 or 2.5, 2.7 or 3.1. They are flexible and open to change. But as a general rule if you find that you are losing muscle tissue you may wish to up your protein slightly BUT I would advise you to check whether your training is effective or whether your caloric deficit is too severe first.

Assuming you have done that, here are my recommendations when setting protein (please refer to the picture underneath for a ballpark comparison if you're unsure of your current body fat percentage):

Again, let me point out that these are not set in stone and I may change my recommendations slightly over time.
You may have noticed that the highest body fat percentage recommendation is below 2.3 grams per kg of LBM. That is intentional. For this person, it's really not worth overly worrying about protein targets so much as getting their calories in order. If they can do that, then any sensible amount of protein is great.

Where Do We Find Proteins?


It makes sense to start here, as animal produce (sorry vegetarians) generally contains larger amounts of protein, and importantly has a complete amino acid profile (meaning they contain all of the essential AAs). Animal proteins also score highly in bioavailability - a measure of how easily a protein is absorbed and used by the body; usually scored out of 100 (when compared to egg protein).

It has limitations which are nicely summed up by Wikipedia here (don't judge me, they did a good job)

Biological Value (BV) provides a good measure of the usability of proteins in a diet and also plays a valuable role in detection of some metabolic diseases. BV is, however, a scientific variable determined under very strict and unnatural conditions. It is not a test designed to evaluate the usability of proteins whilst an organism is in everyday life — indeed the BV of a diet will vary greatly depending on age, weight, health, sex, recent diet, current metabolism, etc. of the organism. In addition BV of the same food varies significantly species to species. Given these limitations BV is still relevant to everyday diet to some extent. No matter the individual or their conditions a protein source with high BV, such as egg, will always be more easily used than a protein source with low BV.

The current best practice (used by WHO) for measuring the quality of protein from foods is called the Protein Digestibility-Corrected Amino Acid Score (PDCAAS). It is a method of evaluating protein quality based on the amino acids contained within them compared to human requirements for them. Feel free to google the proteins you eat regularly to see how they score on their PDCAAS. Here's a few for you to have a quick look see, NPU stands for Net Protein Utilisation.


Arguably the most commonly used source of protein amongst fitness focused people, and for good reason - it's low in fat (though certain parts like the thigh will be higher so always check never assume) and is therefore a good concentrated protein source that isn't compounded by fat or carbohydrate calories coming along for the ride.


Red meat includes Beef, Lamb, Buffalo, Zebra etc. It's another great choice of protein, though generally contains more fat than its white meat counterpart and as a result has a higher calorie count. It's also high in iron, zinc and vitamin B12, all of which are common deficiencies in athletic populations and females in particular. Sadly females usually eat less red meat so let's change that; ladies its time to up your steak game!


White fish is very similar to chicken and turkey in terms of their macronutrient content. Whereas most lean meat tends toward 25g of protein per 100g, fish is usually closer to 20g of protein per 100g.


Oily fish, as the name suggests contains higher amounts of fat compared to white fish. They are high in a group of fats called omega 3's which are beneficial for a whole host of health markers. We will cover these in more detail in the coming section on fat. As well as the fat, the protein content is very similar to white fish at around 20g per 100g.


Another complete amino acid profile protein source. Eggs have long been a staple in fitness circles and for good reason. If consumed with the yolk they are also a great source of fats. At one point in time, there was a concern that this may increase cholesterol levels and potentially contribute to heart disease but that has not born out and there is no longer a recommendation to watch egg intake. So enjoy, but I'd advise you to be aware that like oily fish, it can be easy to go over your fat target if you attempt to get all of your protein intake from food sources that are also high in fat. An easy way around this, when making scrambled egg or omelette's is to use 1-2 whole eggs and a couple of egg whites mixed together


Dairy choices include yoghurt, cheese, milk and ice-cream amongst others. They are all derived from mammal milk of one kind or another, typically cow or goat. This means that almond, rice or soy "milk" is not dairy but a dairy substitute. 
Dairy is typically a combination of whey (a fast digesting) and casein (a slow digesting) proteins. For example whey takes around 4 hours to digest (under fasted conditions) whereas casein will still be seen to affect amino acid levels 7-8 hours later. Both whey and casein are complete amino acids and so are great protein sources.

Clearly we can have high fat dairy proteins, cheese and whole milk. And we can have low fat dairy proteins, cottage cheese and skimmed milk. So the type of dairy choices you make can influence your calories and macros. This can be useful when both dieting, a simple switch to lower fat milk or when trying to add weight, switching to fuller fat alternatives. 


And so we arrive at the vegetarian or plant based options. Generally speaking, most plant proteins have incomplete amino acid profiles which makes them an inferior choice to animal proteins. They are also less bioavailable; you will find most vegetable proteins scoring below 70.

Now that 100% doesn't mean you can't hit your protein targets and get all sexy on a vegetarian (or even vegan) diet. You can. It just means that it is likely a little harder. And, due to the inferior nature of the proteins you can use (especially if you can't consume eggs or dairy) you may need to consume a slightly higher amount of protein to offset the lower bioavailability of the proteins you can eat. This can be difficult to do without crazy amounts of fibre (which will bloat and gas the crap out of you - pun completely intended) coming along for the ride. My advice at that point is usually a protein supplement of some kind - soy, hemp or a combination of brown rice & pea.


Legumes refers to both beans and nuts. Beans tend to be quite high in fibre while nuts tend to be high in fat, though there are exceptions to this; chickpeas for example are a bean that is high in fat. 

It is also quite common to suffer with some bloating when consuming large amounts of legumes, due to sugar fermentation producing gas. Practically speaking this may make hitting your protein targets through only legumes quite difficult - particularly if you wish to keep friends or polite company! 


Other than oils (purely fat) and sweets (purely sugar) most other foods contain proteins. For most fruits and vegetables it is quite an innocuous amount however if you were to eat a sandwich with a few slices of bread a couple of times a day this can actually add quite a bit of protein to the diet. And while they are incomplete protein sources, this is not really an issue in the context of the whole diet (assuming a variety of good sources are consumed). 


Soy is also a legume in that it comes from the soybean. It is special however in that it is has a complete amino acid breakdown; It's only limitation is that it's not as digestible as animal proteins. There is also a slight concern over phytoestrogens, a compound that binds to estrogen receptors in the body and produces a slight estrogenic effect, though it should be noted that the amount required to do so may vary and may be more of a problem, if it is at all, for men than women.


The most commonly used protein powders are either whey or casein based; as mentioned they are both dairy proteins and as a result can cause problems for those with a lactose intolerance (casein in particular).

Other commonly used protein powders include soy, hemp, egg and brown rice & pea.

I'd encourage you to think as protein powders as a food alternative rather than as supplements. They are not magical and are simply a way of getting more protein into the diet quickly and easily. In most of the western world it is more than easy to find carbohydrate and fat sources while on the go, finding a decent protein source while out can be more difficult. As a result keeping a protein shake in your bag is a great way of ensuring you can make a good choice if meetings run late or you find yourself stuck anywhere without access to smart options. In other words it's great for convenience.

Key Points For Protein

Get between 2.3-3.1g per kg of lean body mass per day.
The leaner you are the more protein you need.
If you are larger and are just starting out, please don't worry about any of this, just get your calories right.
When you are dieting and/or weight training, the more protein you need.
Animal Proteins provide a better amino acid profile and are more bioavailable.
If only using Plant Proteins, add an extra 10% to your protein requirements to compensate.