Can You Build Muscle And Lose Fat At The Same Time?

A pair of blue dumbbells with a pair of weight scales, blue medicine ball and black sneakers in the background

For as long as I can remember there has always been an argument circulating in the world of fitness that you must focus on either losing fat or gaining muscle, you can’t do both at the same time.

It’s true that the majority of people will choose a singular goal – either eat as many calories as possible whilst strength training to enable mass gains, or focus on a calorie restricted diet to put their bodies into a caloric deficit to shed unwanted fat.

But can you build muscle and lose fat at the same time? I say you can, and here’s why…

Losing Fat While Gaining Muscle Can Be A Challenge…

Trying to gain muscle and lose fat together can be problematic. I think the basis for differences of opinion on this from both sides of the argument centre around the following:

  • Your body needs to be in a caloric deficit to lose fat. It’s this deficit in calories your body consumes that forces it to use fat already stored in your tissues for fuel.
  • Your body needs to be in a caloric surplus to gain muscle. The surplus provides energy your body needs to repair and build your muscles to increase size.

If you go by these seemingly hard and fast rules it would appear that to build muscle AND lose fat at the same time would be impossible, right? But if we dig a little deeper into the human biology, it isn’t an impossible feat at all.

Let’s Break This Down…

Before I come onto how to lose fat while gaining muscle, let’s just quickly revisit the points above.

To lose fat:

A black and white close up image of a woman's waist as she measures it with a measuring tapeAs mentioned, in order to lose fat you need to consume fewer calories throughout the day than your body burns – this is fat lost explained in its simplest form. If your body doesn’t have enough calories and can’t obtain them through food, then it will start to break down parts of itself to gain this energy. Of course the expectation would be that your body will pull all of this from your fat stores, however energy can also be taken by breaking down muscle depending on how you are training – so it does get a little more complicated! But by training correctly, and consuming the right levels of nutrients from food, you can help prevent this and ensure your body focuses on breaking down excess fat and not muscle.

To gain muscle:
A shirtless, muscular black man flexing his right armTo build muscle you want to lift heavy things and eat enough calories to fuel your body to grow. Again I’m explaining this here its simplest form. To build muscle you need to:

  • Lift heavy – If you lift a weight heavy enough, and enough times, your muscles reach a point of failure which causes them to tear and breakdown. When a muscle rebuilds itself, it will do so bigger and stronger than before.
  • Eat more calories than your body needs – Because your muscles need to be rebuilt post-exercise, you need to obtain calories to fuel this repair and growth. Eating high quality, high protein foods forms a big part of the muscle gaining process.
  • Rest – Your body repairs and rebuilds itself while you’re asleep. The optimum amount of sleep needed is around seven to eight hours per night to enable maximum repair. If you’re not getting this, then you need to go to bed earlier!

Here Comes The Science Bit I Promised You!

When you consume calories from the food you eat your body very quickly gets to work deciding on where to send those calories. If we try to keep things simple here, your body has three routes it can send those calories down:

  1. Burn for energy
  2. Build muscle
  3. Store as fat

A majority of those calories will go down the first route – burn for fuel. This is because there are a certain number of calories your body needs each day just to function normally, i.e. to keep your heart pumping blood and oxygen around your body, to help your brain function, to regulate your body temperature (you get the idea!) so it will automatically direct a lot of the calories you consume into keeping you alive! This is also known as your ‘Total Daily Energy Expenditure’ or TDEE. There are many free TDEE calculators available online if you want to calculate your own TDEE – check out the one I use here.

So, once your body has used up the calories it needs to function normally, the two routes left are ‘Build muscle’ and ‘Store as fat’. If you’re not strength training and breaking down your muscles to create extra demand for these ‘left-over’ calories to be used, your body will take these excess calories and store them as fat. However, our goal is the opposite of this – we want to keep or grow our muscles while getting rid of fat.

So, by incorporating strength training into our daily/weekly routine AND reducing our calorie intake the following happens:

  • Regular strength training will create further demand for calories as you break down your muscles, which creates a need for them to be rebuilt.
  • As you’re not consuming enough calories to both fuel your body’s normal function requirements (TDEE as mentioned above) and rebuild your muscles at the same time, your body now looks to its fat stores for the additional fuel it needs. Your body pulls from your ‘Store as fat’ reserves to make sure it has the energy it requires to keep functioning and repair the damage you have inflicted upon your muscles from strength training.

A quick takeaway from this is, if you have fat stores (and we all do) then you don’t need to be in a calorie surplus to build muscle as the calories your body converts from your fat stores will make up the deficit you’ve been unable to consume through food. BUT, here’s where you need to be careful. Remember above where I said your body can also break down muscle to generate energy as well? There’s a way you can help prevent that from happening.

The Importance Of Protein

A plate of grilled chicken, with red and orange peppers and vegetablesWhen your daily calories are already running at a deficit it’s extremely important to ensure you’re consuming enough protein. Protein is an important component of every cell in the human body, and it’s also used to build and repair tissue, including muscle tissue. Typically, when you reduce your calorie intake, your metabolism (the process by which your body converts what you consume into energy) slows down, which is partly due to muscle loss. However, research indicates that a higher protein intake can help protect against muscle loss and keep your metabolism high. By achieving a higher metabolism you reduce the rate at which your body will use muscle to burn as fuel, and it will instead turn to your fat reserves. When incorporating strength-based training and a low calorie diet into your routine, the result is a decrease in fat and a gradual increase in muscle.

The Takeaway From All Of This?

I’ve tried to keep this article as simple as possible to avoid throwing too much science and confusion around. So let’s keep this summary simple as well.

  • Incorporate strength training into your workouts and eat at a calorie deficit and your body will pull from its fat stores to fuel itself and potentially build muscle too, on the proviso that you…
  • Consume enough protein to keep your metabolism rate high and protect against muscle loss (anywhere between 0.7 – 1 gram of protein per pound, or 1.6 – 2.2 grams per kg, of bodyweight is a good starting point). Remember protein is the number one nutrient for creating new tissue. Studies have shown you can gain muscle even when in a calorie deficit as long as you eat enough protein. I’ve created another blog post on the best high protein foods to gain muscle so check that out.
  • Get enough rest. Your body will only repair and restore itself while you rest, in particular while you sleep, so ensure you get a sufficient amount of sleep per night (aim for between 7-9 hours if you can).

Of course eventually, you’ll reach a point where there isn’t enough fat left on you to help with rebuilding muscle and at this stage you’ll no longer be able to stay in a calorie deficit to grow. Instead, you’ll need to switch to being in a calorie surplus to continue gaining muscle.

Remember That Everyone Is Different

I should perhaps end here by saying that everyone is different. You may find that you’re unable to build muscle whilst eating in a calorie deficit – which is OK. Instead, focus on increasing your calories steadily to a point where you start to see muscle growth while minimising fat gain (a good indicator of this is to regularly weigh yourself and measure yourself around your waist – if your weight is going up but your waist measurement is staying the same, or decreasing, then you’re building muscle not fat).

The point I’m trying to make, in a roundabout way, to end this article is that it CAN be done. So if you want to shift some excess fat but maintain your hard-earned muscle, or you want to continue gaining muscle while losing fat because you don’t want to sacrifice those steady gains, then give it a go.

Have you tried gaining muscle and losing fat at the same time? Did it work for you, or are you an advocate of focusing on doing one thing at a time? I’d love to know so please comment below and let’s talk!



  1. Thank you for this article regarding muscle and fat loss which I found really interesting. I think that it is really important to do strength training as our muscle needs to work and grow so we can go about our daily life Picking up shopping, walking upstairs etc. It is also important to combine a good diet with fitness so what you mentioned about protein is so important whether you eat meat or are a vegetarian. 

    Great article thank you 

    • Thanks Imelda. Yes it’s important to keep yourself strong and active – even just to do the every day stuff we often take for granted – the muscles we use in the gym are the same we use to pick up our shopping, throw a ball, run for a taxi etc! And absolutely protein is a key macronutrient – not just for muscle maintenance and mass but for cell regeneration and hair and nails too. 

  2. Hi, thanks for this informative article on building muscles at the same time as losing weight. 

    I tried a lot of stuff in my life, and never got so much into the rules. It always seemed to be too complicated for me to follow everything when comes to making food. I loved to exercise with Saun – T and at one point became a PRO insanity addict lol 

    I will use your advice as you made this “complicated” topic so simple. As I am someone who’s been working on cruise ships where is difficult to maintain your own diet (you can guess why), so now during the pandemic, the ships are not sailing and I am at home. So now I can actually do something about this matter. 

    Thanks a lot,

    • Thanks for your comments Sunny, and I’m glad you found it simple to understand. If you need any further advice or support just let me know. Best of luck to you and I hope you get sailing again soon!

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