For decades, it was considered a hard truth in fitness: to gain muscle, you need a calorie surplus; to lose fat, you need a deficit. However, recent research and real-world results indicate that body recomposition — building muscle while losing fat — is not only possible but also achievable with the right strategy.
In this article, we'll break down exactly how to do it: the nutrition, training, recovery, and hormonal mechanisms that allow muscle growth even when you're eating fewer calories than you burn.
Understanding the Traditional View
To understand how our understanding of gaining muscle in a deficit has changed, we will start with what we used to believe.
Keep in mind that the following was the traditional consensus, and even we used to believe it. This is a great illustration of how things are always changing, and we should never become close-minded.
Muscle Building Requires a Surplus
Muscle hypertrophy — the process of growing muscle tissue — is an anabolic process. "Anabolic" simply means to build up complex molecules from simpler ones.
Therefore, muscle growth typically requires extra energy as it's an anabolic process. This energy surplus provides the calories your body uses for various processes, including;
- Synthesize new muscle proteins
- Repair damaged tissue
- Fuel workouts
In general, this is the optimal choice, especially when aiming to build a significant amount of muscle. However, as we'll see, it's not as true as we once believed.
Fat Loss Requires a Deficit
On the contrary, fat loss is a catabolic process, meaning it's the breakdown of complex molecules into smaller ones. This occurs as your body needs to supply energy.
As such, fat loss only occurs when you consume fewer calories than you burn. This caloric deficit forces the body to tap into fat stores for energy.
So, how can you build something (muscle) while in a state of energy restriction? It seems contradictory — but with the right inputs, it's not.
Only Specific Populations Can Build Muscle While In A Deficit
Even in the past, researchers still believed that some populations could successfully build muscle while in a calorie deficit. These populations included;
- Beginners: Their bodies are more sensitive to training and adapt quickly.
- Detrained Individuals: People returning after time off often experience "a phenomenon known as 'muscle memory.'
- Overweight Individuals: Their stored fat provides ample energy for muscle building.
While this is still true, more research has shown that everyone can gain muscle and burn fat simultaneously.
Can You Build Muscle in a Caloric Deficit?
In short – Yes!!!
As research has evolved, we've learned that our bodies are much more complex than we previously believed.¹ These processes do not function in a box as many other variables can influence them.
Over the past few years, numerous studies have shown that you can definitely build muscle, even when not in a calorie surplus. In fact, here are just two studies that show you can burn fat at the same time – a true body recomp.
Study 1 - In 2015, Dr. Jose Antonio had two groups of resistance-trained individuals follow a heavy resistance training program. One group ate 3.4g/kg of protein daily, while the other group ate 2.3g/kg.²
Both groups experienced an increase in muscle mass, while the higher-protein group also saw a decrease in fat.
Study 2 - In 2020, researchers had two groups of aspiring women physique athletes follow two different diets: a low-protein diet and a high-protein diet.³
We should note that not all the participants were necessarily in a deficit. Some individuals appear to be on a hypercaloric diet, yet they are still able to build muscle and lose fat simultaneously.
Regardless, these show that our bodies do not function under strict guidelines.
5 Steps To Gain Muscle In A Deficit
Now that we know you can build muscle, here's what you need to do to achieve it.
1. Get In A Small Caloric Deficit (<200 Calories)
Building muscle in a calorie deficit requires that you enter a small caloric deficit. If you go too low, you can make it very difficult to put on muscle.
Therefore, although it is difficult to determine the exact amount, we recommend consuming less than 200 calories.
2. Eat High Protein
Of your three macronutrients, protein is the most important when it comes to building muscle – this is especially true when building muscle in a caloric deficit.
Adequate protein is essential for building muscle as it contains amino acids – the building blocks of muscle. As you're in a deficit, this is exacerbated.
At the same time, eating high protein has multiple benefits when performing a body recomposition as it;
- Keeps You Feeling Full - Protein has the highest satiety effect, meaning it keeps you feeling full. This helps manage your caloric intake.
- Has a High Thermogenic Effect of Food (TEF) - TEF is the amount of calories your body needs to digest food and utilize its nutrients.¹
Regardless, research indicates that achieving a successful body composition is associated with consuming a high-protein diet. Here are the necessary daily doses.
- 2.0g per kg (0.9g per lb) - This is the bare minimum you should eat if you want to build muscle while in a deficit.
- 2.5g per kg (1.15g per lb) - Research shows significantly better results when eating 2.5g/kg, and it should ideally be what you aim for.
- 3.0g per kg (1.4g per lb) - Having even higher amounts of protein could yield even greater results.
3. Train Heavy And With Intensity
To build muscle, you need to train in a way that promotes muscle growth.
When you go to the gym, remember that you still need to train with intensity – you're not just going through the motions.
Therefore, run a proper muscle-building program and still train with progressive overload as the goal.
If you need a full program, check out this article for an awesome 8-week body recomp program.
4. Prioritize Sleep
This isn't just rhetoric – Sleep is much more important for muscle growth than many people realize. Its role is then exacerbated when the body is in a deficit, as it can break down muscle for fuel rather than fat.
And research shows this. Being deprived of just 1-2 hours of Sleep during the week can put your body in an increased catabolic state.
GET YOUR SLEEP!
5. Consider Proper Supplementation
Supplementation is not the number one priority. Your primary priority is eating a whole-food diet and getting your calories and macros.
However, if all that is dialed in, supplementation can give you the boost you need.
Of all supplements, when it comes to building muscle, the two primary products we recommend are;
- Quality Protein Powder - Protein powder isn't necessary, but it does make hitting your protein.
- Creatine - Creatine is the most effective supplement we know of. It will help build muscle and provide energy as you're training in a deficit.
6. Use HIIT And Walking, But Stay Away From Long Cardio Sessions
We're definitely not anti-cardio or steady-state. However, when wanting to build muscle while in a deficit, excessive cardio can raise cortisol and create a greater catabolic state,
You don't want this.
Therefore, use either HIIT or increase your steps for cardio.
Full Plan To Put On Mass While In A Deficit
Below, we will outline a plan for adding lean mass with fewer calories.
Training Program For A Body Recomp
- Primarily use compound exercises
- Hit every muscle group twice a week
- Use a range of loads and reps (5-12)
- Increase steps and use HIIT for cardio
Diet Guidelines For A Body Recomp
Here's a breakdown of calories and macros.
- Calories - No more than a 200 caloric deficit.
- Protein - At least 2.5g/kg of quality protein daily.
- Fats - At least 30% of your total calories
- Carbs - Fill in the rest of your calories with carbs
Misc.
- Get at least 7 hours of quality sleep nightly
- Supplement with creatine
- Supplement with protein powder if you need help hitting your goals.
Frequently Asked Questions
Can fat turn into muscle?
No. Fat and muscle are different tissues. You lose fat through a calorie deficit and gain muscle through resistance training and adequate protein intake. They don't "convert" — but they can change your physique simultaneously.
Should I cut first or bulk?
It depends. If you have a body fat percentage of over 20% (men) or 30% (women), start with a fat loss phase. If you're leaner, you can attempt recomposition directly.
Can I do a recomp forever?
Ideally, you’ll reach a point where you have no more fat to burn! Jokes aside, we wouldn’t recommend staying in a deficit “forever”. However, you could be in a surplus and increase your protein intake to perform a recomp as well. Just keep in mind that it could become mentally draining as you must always be on point. Therefore, we would recommend some breaks.
Will I lose muscle in a deficit?
Not if you're lifting weights, eating enough protein, and getting enough sleep. The body will prioritize fat loss first, especially when proper training and recovery are in place.
Can You Gain Muscle In A Caloric Deficit? Final Analysis
In short, yes, you can. However, it requires you to be even more precise with your nutrition and training when compared with trying to lose weight. While the different physiological systems give you a pathway to make it possible, these systems can also prevent it if you don't find the right balance.
Also, muscle growth will occur at a slower rate than if you were in a surplus. So, while it may take time, you won't have to worry about gaining fat, making it a great option for those who are not in a rush and do not want to gain weight.
References
- Slater GJ, Dieter BP, Marsh DJ, Helms ER, Shaw G, Iraki J. Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated With Resistance Training. Front Nutr. 2019;6:131. Published 2019 Aug 20. doi:10.3389/fnut.2019.00131 https://pubmed.ncbi.nlm.nih.gov/31482093/
- Antonio, J., Ellerbroek, A., Silver, T. et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women – a follow-up investigation. J Int Soc Sports Nutr 12, 39 (2015). https://doi.org/10.1186/s12970-015-0100-0
- Campbell BI, Aguilar D, Conlin L, et al. Effects of High Versus Low Protein Intake on Body Composition and Maximal Strength in Aspiring Female Physique Athletes Engaging in an 8-Week Resistance Training Program. International Journal of Sport Nutrition and Exercise Metabolism. 2018;28(6):580-585. doi:10.1123/ijsnem.2017-0389 https://journals.humankinetics.com/view/journals/ijsnem/28/6/article-p580.xml
- Barakat, Christopher MS, ATC, CISSN1; Pearson, Jeremy MS1; Escalante, Guillermo DSc, MBA, ATC, CSCS, CISSN2; Campbell, Bill PhD, CSCS, FISSN3; De Souza, Eduardo O. PhD1. Body Recomposition: Can Trained Individuals Build Muscle and Lose Fat at the Same Time?. Strength and Conditioning Journal 42(5):p 7-21, October 2020. | DOI: 10.1519/SSC.0000000000000584 https://journals.lww.com/nsca-scj/fulltext/2020/10000/body_recomposition__can_trained_individuals_build.3.aspx
Garett Reid
Author