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Home » Body Recomposition: Build Muscle And Lose Fat At The Same Time

Body Recomposition: Build Muscle And Lose Fat At The Same Time


What is body recomposition?

Body recomposition is the idea of building muscle and losing fat at the same time. Or in other words, building muscle while on a caloric deficit.

This right here is one of the oldest and most controversial topics in the history of fitness and bodybuilding.

Speak your mind on the subject and you’re sure as hell going to have an angry mob after yourself.

I mean, after all:

One of the most common pieces of advice that you will hear from fitness experts and influencers is:

In order to lose body weight you need to be in a caloric deficit –  i.e. eat fewer calories than your body requires to maintain its weight.

And in order to gain muscle mass you need to be in a caloric surplus – i.e. eat more calories than your body requires to maintain its weight).

Breon Ansley, two time Mr. Olympia classic physique champion, famously said in a video where he was asked whether you can build muscle in a caloric deficit “NO!”.

Does that mean that if you want to build muscle, but you also want to lose fat that you need to cut first and then bulk. Or bulk first and then cut?

After all, asking whether body recomposition is possible is also asking whether bulking and cutting phases are necessary. It also touches on the topic of maingaining, but for now let’s just focus on recomp.

The short answer is that not only is body recomposition possible, it’s expected.

But why should you listen to me, while there are so many people telling you the exact opposite?

Allow me to take a more scientific approach and let’s first go over what exactly is the muscle building process.

The science of muscle growth



I’ll try and be less technical and boring.

Muscle growth is a signaling dependent process.

The signaling can be broken down into two categories – physical exercise signaling and nutritional signaling.

Let’s take a look at the physical one first.

We lift a weight heavy enough to create active mechanical tension in the muscle. This is called a stimulus.

The stimulus is sensed by sensors, which feel that the muscle is pulled into tension and pass that signal on to a molecule called mTOR. mTOR is one of the main things that control the growth of cells in the body.

From there, the mTOR goes to the nucleus of the cell and tells the DNA machinery to create a mRNA strand (sort of like a blueprint for building new muscle).

Those blueprints are sent to a Ribosome, which is like a muscle building factory, that manufactures a string of amino acids based on the blueprint in a process known as translation.

Translation is what you’ve commonly heard being referred to as muscle protein synthesis.

If protein synthesis is greater than protein breakdown (i.e. synthesis > breakdown) then new muscle fibers are created leading to more muscle size.

The nutritional signaling is triggered from amino acids in the protein we eat.

Here, the amino acids are transported into the cell where one of the 9 essential amino acids, Leucine, also activates mTOR.

Then the other 8 essential amino acids make their way to the ribosome where they are used as the fundamental building blocks for building muscle.

I know, I know.

Not the most exciting stuff. But understanding how muscle growth works is essential to understand why body recomposition works.

To summarize:

Exercise is what promotes muscle growth while protein helps support the process and provide the building blocks necessary to repair and build muscle.

So far nothing new. We already know this.

But the main keyword here is “caloric deficit” or “caloric surplus”. So, what role do calories play in all of this?

Well let’s have a closer look into what calories are.


What are calories


Calories are a unit of energy that are contained in food.

But not all calories are created equal.

There are three main caloric sources: carbs (1g = 4 calories), protein (1g = 4 calories), and fats (1g = 9 calories).

These three are commonly referred to as macronutrients or macros.

The energy gained from these macros is used differently by the body.

Carbs are used as your primary energy source – everything from walking to your brain function is powered by them.

Protein calories are used to rebuild and build tissue- from organs, to muscles, to hair.

Calories from fats are used by the body to support cell growth, energy when broken down into fatty acids, protect your organs, promote the production of important hormones, etc.

The calories you gain from these three macros serve a different purpose.

Yes, they all can be technically used for energy to fuel daily activities, but the body has a structure that makes the whole process more efficient and reduces waste.

So, does that mean that when you’re in a caloric surplus that you gain all of those calories just from protein. Is all of that excessive protein calories what drives muscle growth.


That would be impossible, if you had to be in a 500 caloric surplus that means that you’d have to eat 125 grams of protein ABOVE what you’re already eating.

When you’re bulking, the majority of your calories come from carbs and fats – both of which have NOTHING to do (sort of) with muscle growth.

What you are essentially doing when you’re bulking is introducing a lot more energy in your body than what it needs to maintain your weight. 

And what happens with all of that excess energy?

It gets stored as body fat.

This study shows how by placing participants in a caloric surplus of 600 calories. What happened?

They gained three times as much fat and they gained…

Wait for it.

0.5% more muscle than the control group who were not in a caloric surplus.

body recomposition study

I’ll repeat that again, 3 times more body fat and only 0.5% more muscle than the group that was not in a caloric surplus.

And even bold it.

And there’s this study, where the researchers concluded:

“…there does not appear to be any metabolic or functional benefit to the source of the energy surplus”

Here’s the worst part.

Even if you gained more muscle during your bulking phase, you’re probably going to lose it all during your cutting phase.

Bulking only creates a short-term illusion of adding strength and size. And once you enter in a caloric deficit, and your body weight drops as a result, and you’re not able to push as heavy loads at the gym, you’re going to lose all of the bonus muscle you had gained.


Let’s do some muscle math.

In a realistic example, let’s say that you’ve been working out for 3 months.

Let’s say you’ve gained 2kg of muscle (4.4lbs) and lost 1 kg (2.2lbs) of fat.

We know that 1kg of muscle is equal to 1,800 calories.

While 1kg of fat is equal to 9,400 calories.

This is because muscle is mostly made up of water, it has a lot less stored energy than fat does.

So that means that in the time span of those three months you would’ve gained 3,600 calories.

And lost 9,400 calories.

So even though you would’ve gained 1kg (2.2lbs) of total bodyweight, there was a total net energy deficit of 5,800 calories, spread across those three months.

Or a deficit of 65 calories per day.

And this is only scratching the surface, there is a plethora of scientific literature that shows us that body recomposition is absolutely achievable.

This 2016 study, for example, shows that on average subjects lost about 5kg (11lbs) of fat mass, while gaining about a 1kg of lean muscle mass.

But most participants in such studies are usually novice trainees. People who had just recently started working out and gotten on a high protein diet of 1g per 1lbs. And they were using progressive overload in their workouts – i.e. gradually increasing the weight, frequency, or number of repetitions and sets when exercising a muscle.

So this begs the question:

Is body recomposition possible for someone who has been exercising for some time now.


Is body recomposition for everyone?

For the longest time, people used to believe that body recomposition can only occur in untrained new lifters and overweight people.

Makes sense, new lifters have the tendency to easily put on muscle and overweight people have large reserves of energy stored as body fat.

But recent data shows us that even experienced athletes are capable of building muscle while losing fat as shown in this study.

What about people with low body fat percentages?

Probably the only people who cannot benefit from body recomposition are those who already have low body fat percentages – say 6-10%.

But then, you don’t need to be in a caloric deficit.

If you continue dieting you’re going to increase the risk of losing muscle mass. As your body fat percentage drops, your body will do its best to maintain its body fat storages and will break down muscle tissue to decrease the total amount of calories necessary.

Because more muscle also means you burn more calories. Your BMR increases.

As a result you will also lack the necessary calories to help fuel your workouts and be able to lift heavier weights and maintain the intensity of your training.

If you’re in such a situation it would benefit you to eat more.


Bottom line

In conclusion, you can absolutely build muscle in a caloric deficit.

It’s not just for novice lifters or overweight people. It’s achievable by anyone.

But body recomposition is not desired when you’re already at low body fat percentages. As you’re going to jeopardize your muscle mass and strength.

Make sure that you’re eating a high protein diet of 0.8g to 1g of protein per pound of bodyweight. So, if you weigh 170lbs (77kg) eat about 136g to 170g of protein.

And make sure that you’re using progressive overload in your workouts.

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