Can You Build Muscle in a Calorie Deficit? A Trainer’s Opinion

Can you build muscle in a calorie deficit? If so, what’s the best way to go about doing so? Here’s everything you need to know.

Long story short, it is possible to gain muscle on a caloric deficit. Not everyone can do it, and not everyone can do it to the same extent.

But it can be done.

Today, I want to take a closer look at the results from one of the many studies showing that losing body fat and building muscle can happen simultaneously.

Then I’ll talk about how it happened, as well as explaining the best way to go about gaining muscle in a deficit.

Let’s jump right in.

What Is a Calorie Deficit?

You’re said to be in a calorie deficit when you’re burning off more energy than you get from your diet.

When you’re in a caloric deficit, there’s less energy coming from the food you eat than your body needs to move, pump blood around your body and all the other stuff involved in keeping you alive.

The total number of calories you burn in a day, also known as your total daily energy expenditure (TDEE for short) is a combination of several factors. These are:

• Your basal metabolic rate.
• The amount of energy you burn during exercise.
• Any daily activity you do outside the gym.
• The energy cost of digesting and processing the food you eat.

For example, if your total daily energy expenditure is 3000 calories per day, but you’re only getting 2500 calories from your diet, your total calorie deficit is 500 calories.

Because there’s now a mismatch between the amount of fuel your body needs and the amount it gets from food, it starts looking for something to plug the gap.

In most cases, that alternative will be the large depot of chemical energy stored in your body known as fat.

Some say that it’s impossible to gain muscle in a caloric deficit, mainly on the basis that building muscle is an energy intensive process requiring a calorie surplus.

In truth, a calorie surplus isn’t necessary in order to gain muscle tissue. That’s because your body can use the energy supplied by body fat to power muscle growth.

How Your Calorie Intake Affects the Amount of Muscle You Build

Research shows that muscle hypertrophy tends to happen a lot more slowly when you’re in a deficit compared to a surplus [1].

That is, eating fewer calories to the extent that you’re in a deficit makes the process of building muscle a lot slower compared to being in a calorie surplus.

That’s because one of the things that slows muscle protein synthesis – the key driving force behind muscle growth – is a restriction in the availability of energy.

Were you satisfied with your rate of muscle growth when you were in a caloric surplus?

Probably not.

You’ll be even less satisfied when you’re in a caloric deficit, because the gains will come a lot more slowly.

In an ideal world, you’d like your body weight to stay the same, with every pound of fat mass lost replaced with a pound of lean muscle mass (AKA body recomposition).

This is highly likely not going to happen.

With very few exceptions, you won’t build muscle tissue at anything like the same speed at which you lose fat. Which means that for most people, fat loss is going to mean weight loss.

How to Tell if You’re Gaining Muscle While Losing Fat

How can you tell if you’re losing fat while gaining muscle at the same time?

Stepping on the bathroom scales, the way that most people measure progress, gives you a limited picture about how your body composition is changing.

If you lose 10 pounds of fat while gaining 5 pounds of muscle, your weight will change by just 5 pounds. But your body composition has changed by 15 pounds.

Most tools available for tracking changes in body composition, such as DEXA or body fat scales, have a large margin of error. None can be relied on to give you an accurate assessment of your progress.

Instead, I suggest keeping track of your waist size, your weight on the scales, and your performance in the gym. 

And by performance in the gym, I’m talking about the amount of weight you can lift for a given number of reps, or the number of reps you’re able to do with a given amount of weight.

If your weight on the scales is going down, your waist size is shrinking, but your numbers in the gym are going up, those are all positive signs that you’re on the right track and what you’re doing is working.

How to Build Muscle in a Calorie Deficit

If you want to gain muscle in a caloric deficit, what’s the best way to go about it?

First, make sure that you do some form of resistance training at least twice a week. Three times a week will be better. And, if you’ve got the time, four workouts a week is better than three.

That’s not to say you can’t do more. In fact, there’s no good reason why you can’t lift weights 5-6 times a week, just as long as your workout program is set up properly.

However, for most people wanting to gain muscle while losing fat, four days of weight training a week is plenty.

Although there are many effective training programs out there, a 4-day upper/lower split, where you work the upper and lower body muscle groups on separate days, is one of my favorites.

You’ll find a complete 4-day upper/lower split here.

As for cardio, it’s useful in certain circumstances, but not essential. As long as your diet is set up properly, losing fat doesn’t have to involve any cardio at all.

Nutrition for Building Muscle and Burning Fat

On the nutrition side of things, there are two key things to focus on:

1. Make sure the calorie deficit isn’t too large
2. Eat a high-protein diet

If the number of calories you eat each day is too low, you’ll struggle to hold on to the muscle you have right now, let alone gain any more.

Setting your daily caloric intake will depend on a number of factors, one of the main ones being the amount of fat you have to lose in the first place.

If you’ve got a large amount of fat to lose, you can still build muscle while maintaining a relatively large energy deficit. But as you get leaner, the more extreme the deficit, the higher the risk of muscle loss.

How much of a calorie deficit should you be in to lose fat and gain muscle?

As a general rule, aim for a calorie deficit somewhere between 15-20% below your maintenance calorie intake.

And by maintenance calorie intake, I’m talking about the number of calories you need each day to maintain your weight.

That is, if you need 2500 calories each day to maintain your weight, you’d aim for somewhere between 2000 and 2125 calories per day.

Can you build muscle on a calorie deficit with enough protein?

What about protein intake? How much protein should you eat to gain muscle while losing fat?

Aim for roughly 0.7 grams of protein per pound of body weight per day, or around 1.6 grams per kilogram [2, 3].

Without enough protein, you’ll find it extremely difficult to retain muscle mass, let alone gain any.

Once your protein intake is taken care of, the rest of the calories in your diet will come from carbohydrate and fat.

For most people, carbohydrate intake should average somewhere between 30 and 50 percent of daily calorie intake. 

There’s no rule that says it has to stay the same from one day to the next. Some days you might eat a little more carbohydrate, others a little less. But on average, it should be around 30-50 percent of total calories.

In summary, some people can and do build a decent amount of muscle while they’re in a calorie deficit.

But it’s a phenomenon that’s generally limited to people who are very overweight and have never lifted weights before, or those who are returning to exercise after a layoff, where muscle memory comes into play.

Once you’ve move past the “overweight beginner” stage, building a significant amount of muscle while losing fat is a goal that becomes progressively more difficult.

Frequently Asked Questions

Is bulking necessary or can you build muscle well enough in a deficit?

Overweight beginners can expect to build a decent amount of muscle in a deficit. But more advanced lifters are better off focusing on fat loss or muscle growth, using a traditional bulk or cut approach.

Can I lose muscle mass in a calorie deficit?

Yes, you can lose muscle in a calorie deficit. Cutting calories too much, combined with a low-protein diet and little or no resistance training can increase the rate of muscle protein breakdown, which will lead to muscle being lost.

If I am eating in a calorie deficit but also gaining muscle should my weight go up or down?

If you’re eating in a calorie deficit, but gaining muscle at the same time, it’s far more likely that your weight will go down rather than up.

That’s because fat is lost more quickly than muscle is gained tends to happen a lot faster than gaining muscle. Most people can lose a pound or two of fat over the course of a week without too much trouble.

But gaining the same amount of muscle can take anywhere from several weeks to several months (and eventually a lot longer), depending on your training status (beginner, intermediate or advanced) and what your muscle-building genetics are like.

What happens if I eat enough protein but not enough calories

If you eat enough protein but not enough calories (meaning that you’re in a calorie deficit), then you’re going to lose weight. Add weight training to the mix, and you’ll likely gain some muscle at the same time.

Why am I gaining weight in a calorie deficit and working out?

There are two possible reasons why you’re gaining weight in a calorie deficit. The first is that you’re gaining muscle more quickly than you’re losing fat. That is, if you gain 5 pounds of muscle while losing 4 pounds of fat, you’ll have gained a pound in weight.

However, while this scenario is not impossible, it’s highly unlikely. Most people lose fat a lot more quickly than they gain muscle.

The second reason is that you’re not actually in a calorie deficit. You might think you are, but you’re not. This is the most likely reason why someone is gaining weight in a (supposed) calorie deficit, and is typically due to underestimating your calorie intake and/or overestimating calorie expenditure.