What Is A Calorie Deficit? (And How To Create One)

By JC Deen



caloric deficit intro

A calorie deficit is created when you eat fewer calories than your body burns over an extended period of time (anywhere from a day to multiple months). 

Hence, Losing weight is the result of creating a calorie deficit. 

To create a calorie deficit, we’re going to cover the various ways to go about this, which tends to happen through a combination of restricting your diet and regular exercise.

In one of the most recent nutrition reviews (July 2019), it’s clearly stated that a diet with a negative energy balance is what creates weight loss:

In the short-term, high-protein-low-carb diets and intermittent fasting are suggested to promote higher weight loss and could be adopted as a jump-start. However, due to the adverse effects caution is required. In the long-term, current evidence indicates that different diets promoted similar weight loss and adherence to diets will predict their success. Finally, it is fundamental to adopt a diet that creates a negative energy balance and focuses on good food quality to promote health.

JC’s emphasis in the bold.

While the body is more complex than a basic math problem, one of the easiest ways to understand how a calorie deficit works is to do simple math.

Let’s say you burn 2,500 calories per day.

To create a calorie deficit, one would simply eat fewer than 2,500 calories.

You could eat 1,800, 2,000, or 2,499 calories and still be in a caloric deficit, technically.

Here’s how the math works out:

  • 2,500 – 1,800 = 700 calorie deficit
  • 2,500 – 2,000 = 500 calorie deficit
  • 2,500 – 2,499 = 1 calorie deficit*

*Note: this is only an example to show you that a caloric deficit is all about how many calories you take in versus what you’re burning daily.

No one in their right mind would ever recommend that you try to eat 1 less calorie per day because it’s impossible to calculate and track calories that closely. 

While this is an elementary explanation, these are the fundamentals of how weight loss works through a caloric deficit.

However, there’s more to know about how to properly create a calorie deficit.

In order to unpack this in full, we’re going to cover every aspect of how to create a caloric deficit that helps you lose fat, not muscle

Because remember: weight loss isn’t the same as fat loss.

Fat Loss Requires A Caloric Deficit

Despite what you may have read or heard, there is no way to make fat loss happen without creating a caloric deficit.

For most people, the combination of restricting your calorie intake and exercising is ideal to lose weight and keep it off. 

You can increase your expenditure through exercising more or you can reduce how much you eat to ensure you’re creating a caloric deficit. 

How To Create A Caloric Deficit

As mentioned, there are two ways:

  • Exercise
  • Controlling your calorie intake

If you want to improve your body composition, then you’ll want to be doing some form of resistance training.

If you need specific instructions on how much you should workout, you can check out my programs and my free fat loss workout.

Exercise Burns Calories

Any time you exercise, whether you go for a walk, or hit the gym for an intense workout, you’re burning calories.

Exercise is often seen as the best way to lose weight because it helps you burn more calories over time.

However, you need to be brutally aware of one thing:

Exercise doesn’t burn as many calories as most tend to think.

In fact, there was a study showing that people perceived their caloric burn to be much higher than it actually was:

In this study, Normal weight men and women overestimate exercise energy expenditure, we get the following:

CONCLUSION: These results suggest that normal weight individuals overestimate EE (energy expenditure) during exercise by 3-4 folds. Further, when asked to precisely compensate for exercise EE with food intake, the resulting energy intake is still 2 to 3 folds greater than the measured EE of exercise.

JC’s emphasis in bold

This shows us that when studied, we tend to overestimate how much energy we burn during exercise. And it’s to the tune of overestimating calories burned by 3-4x more.

Let’s say an average cardio session or weight training workout lasting 45-60 minutes burns 200 calories.

That means most people would estimate they burned 600-800 calories during that session.

This is mostly due to your rate of perceived exertion.

But just because you perceive a workout to be incredibly challenging and tiring, it’s not actually burning as many calories as you think.

Here’s an illustration to understand this clearly.

calorie deficit

This is why you shouldn’t rely on how you feel in terms of exertion.

Just because you feel like you burned 1,000 calories on that hard run, doesn’t mean you actually did.

In fact, studies show us it was a fraction of that.

And that’s why you shouldn’t rely on exercise alone to create a caloric deficit.

Restricting Your Intake Ensures You’re In A Caloric Deficit

Now that you know humans are notoriously bad at estimating how many calories they’re burning during exercise, the only reliable way to put yourself into a caloric deficit is by managing your calorie intake.

And that’s why you’ll want to carefully track your food intake and make sure you stick to your diet

How do we go about creating a caloric deficit?

It’s all about math.

fat loss

Calculating A Caloric Deficit

The fastest way to get an idea of how much food you need to create a caloric deficit is to use my maintenance and fat loss calculator.


Napkin Math Caloric Deficit

If you’d rather do some napkin math, you can follow this short guide.

In general, a person will typically maintain their body weight within the range of 13-16 calories per pound of body weight.

This falls in line with the research and the tools I used to build my maintenance calorie calculator.

For fat loss, there’s also a range. And that tends to be 10-12 calories per pound of body weight.

For muscle gain, you need a caloric surplus, and that range can be 17-20+ calories per pound.

See my bulking guide for the full details on building muscle.

As you might imagine, if you’re trying to calculate your caloric deficit, the numbers will vary from person to person.

I always recommend you eat as much food as you possibly can while still being able to lose fat at a reasonable rate.

Let’s do some simple math.

If you weigh 150 pounds, you can create the calorie deficit like so:

  • 150×12 = 1,800 calories

Now that would be where I’d recommend you start because it’s at the upper end of the range. 

If you’re not consistently losing weight in the form of body fat after 2 weeks, you’ll want to lower your calories again. 

You could then multiply your body weight by 11 and track that intake for a few weeks and see what happens to your weight.

Ideally, you’ll lose anywhere from .5 to 1 pound of body weight per week.

How Big Should The Deficit Be?

Like I mentioned above, you want to eat as much food as you possibly can while still being able to lose fat.

Many ask the question: 

“Why not create a big calorie deficit, such as 1,000+ calories below maintenance in order to lose fat fast?”

While this sounds great on paper, it’s not ideal in the real world for two reasons:

  • You’re going to be very hungry, especially if slashing 1,000 calories from your maintenance means you’re living on less than 1,200 calories per day.
  • You’re more likely to lose muscle because the calorie deficit is too big.

In general, I recommend no more than a 500 calorie per day deficit throughout the week.

And then I recommend a substantial carb refeed one day per week.

The easiest method is to use my calculator and use that as a means for setting up your caloric deficit.

To be clear, I classify the size of caloric deficits below:

  • Small calorie deficit (-300 calories per day)
  • Moderate calorie deficit (-500 to -700 calories per day)
  • Large deficit (-800 or more calories per day)

Note: the larger the deficit, the harder it will be to stick with.

If you try to lose fat fast with a larger deficit, you’ll have to incorporate regular carbohydrate refeeds.

Should You Calculate Your Calories Burned From Exercise Devices And Machines?

No, and here’s why.

It’s been reported over and over that wearable fit band calorie trackers are way off in terms of their accuracy.

Here’s a quote from The Washington Post:

A team of Stanford researchers, however, recently called foul after testing these trackers. The scientists said in a paper published Wednesday in the Journal of Personalized Medicine that though the devices purport to help users track their calories — daily energy expenditure — the number is often markedly incorrect.

The least accurate, PulseOn, was off by an average of 93 percent. The most accurate device, Fitbit Surge, was off by an average of 27 percent, the Guardian reported.

In a statement to NPR, PulseOn said the extremely high level of inaccuracy may “suggest that the authors may not have properly set all the user parameters on the device.”

The consequences of such large margins of error could, of course, be significant.

And for exercise machines… well, that number on the display congratulating you on that 800 calories burned is probably way off. Here’s an excerpt from an article by Steve Ledbetter (Coach Stevo):

Your treadmill got that number the same way that the EPA gets gas mileage numbers: estimations and averages. Scientists had a lot of people run on a treadmill hooked up to a mask that calculated the amount of air they breathed, then used that to estimate the amount of calories were required to do the effort. Then they got an average over the sample and put that average into the treadmill, which spits out a number based on how much you weigh and how fast the drums were turning.

This number is pretty good … if you’re close to the average and do everything the way the people in the tests did. But did you?

Do you weigh what they weighed? Did you put your hands on the rails? Do you have the same ratio of fat to muscle? Did you work as hard per minute?

Your detergent should be as powerful as you are. Shop Sweat X now.

The number on that treadmill is probably wrong as it relates to you and not the testers (unless you are very close to the average and do everything the same as the testers did). But the more you deviate from the mean, the less likely the mean is an accurate way to predict your actual calorie usage. Let me show you what I mean with gas mileage.

It’s common to want to eat back those calories they burned on an exercise machine.

But as noted in the reports above… you’ll see that idea is faulty due to the incorrect readings the device might give you.

Your Baseline Maintenance Requirements

Everyone burns a certain amount of calories throughout the day.

And it will vary based on many variables such as:

  • How active you are
  • How much sleep you got
  • Did you exercise? If so, how long?
  • What you ate
  • Stress levels

The amount of calories you burn to maintain your body weight are known as your ‘maintenance caloric intake.

That’s why you’ll see people often using the word ‘maintenance’ when they discuss their weight loss efforts. 

For instance, you might have seen someone say “I’m trying to figure out my maintenance intake.” or “I’m having a hard time staying under maintenance due to intense hunger pangs.”

Another way to think about your maintenance requirements is through your unique metabolic rate or your total daily energy expenditure.

To learn more, you’ll want to check out this article on maintenance calories.

Your Unique Energy Expenditure

Everything you do burns calories. From sleeping to eating to thinking hard trying to solve a problem.

And how we burn this energy falls into a few categories. Those are:

  • BMR (basal metabolic rate)
  • TDEE (total daily energy expenditure)
  • NEAT (non-exercise activity thermogenesis)
  • TEF (thermic effect of food)

Your BMR is what your body burns at complete rest. It’s the bare minimum you would burn if you slept all day and your body was just doing all of its automatic processes. Things like breathing, keeping your heart beating, cell repair, etc.

Your TDEE is your true body’s requirements in terms of how many calories you’re burning daily. It takes into account your BMR, plus all the activities you do during the day.

NEAT is just a way of labeling all the activity you participate in that’s not deliberate exercise. For instance, if you walk to the train every day for work, that’s not deliberate exercise. But going out for a run or to the gym to lift weights is.

TEF is the energy your body burns through digestion. This is really nothing to worry about because while some foods have a higher thermic effect than others, you can’t solely rely on those foods alone because your diet would be devoid of nutrients.

We’ve covered everything you need to know in our energy expenditure article, so make sure you check that out.

Determining Your Maintenance Intake

Now that you know what makes up your maintenance intake, you must determine what your maintenance intake is in order to establish a proper calorie deficit.

There are two ways to go about figuring out how much food it takes to maintain your weight:

  • Track what you eat over the next 10 days and take the average
  • Use my calculator (below)

Track Your Habitual Food Intake

This sounds simple, but it’s harder than you think.

Your job for the next 10 days is to track everything you put into your mouth that contains calories. That’s it. 

If you’ve never tracked your daily intake before, this can be an enlightening experience.

Here’s how to do it.

Step 1: Begin The Tracking Process

You’ll want to have a method of tracking. You can use an app (recommended) like Cronometer, MyFitnessPal, or another similar macronutrient tracking app. 

Here’s a quick video of how I use Cronometer:

Alternatively, you can use a pen and paper. (but c’mon, we live in the future with all kinds of apps and gadgets…)

Step 2: Track It All Accurately

You’ll need to start recording your food accurately.

Anyone can simply write down what they had for breakfast:

  • Cup of coffee with cream and sugar
  • 2 slices of toast
  • 2 fried eggs
  • Bowl of oatmeal with butter and brown sugar

If you’ve never kept a food journal, this is a good start.

Simply writing it down can be insightful.

And while you could look up these foods and their caloric values, you’re not going to be as accurate as you could be.

By the way, I have a comprehensive guide on how to count macros

A better way to track would be using a kitchen scale to measure how much you’re actually getting.

A regular cup of coffee contains almost no calories… maybe 5-10 at most. 

But a cup of coffee with cream and sugar contains far more than 5 calories per cup. 

And the amount of cream and sugar you use will determine how many calories are in that coffee.

2 slices of toast… not too hard to track. Just look at the bread bag’s nutrition facts. But what if you buttered that toast? 

The calories will go up.

This same process applies to the rest of your breakfast (or any other meal).

Now if you don’t know how to use a kitchen scale for counting macros, I have you covered.

Here’s how to use a kitchen scale (and why I recommend it over a scoop):

Step 3: Do This For 10 Days

Follow the rules above to track Every. Single. Thing. you eat for the next 10 days. The goal is to know with high accuracy how much food you ate daily over that 10 day period.

And during this time, you’ll also want to track your daily weight. Yes, that means you’ll step on the scale every day during this period.

The reason for this is because your body weight fluctuates on a daily basis, so just randomly weighing yourself throughout the week will tell you very little about how much you actually weigh.

And oftentimes, when someone is trying to lose weight, they will get discouraged about their lack of weight loss whenever they see the number on the scale move upward.

But in reality, any single recording on the scale weight is meaningless without having more data.

Case in point: I can weigh myself in the morning before eating or drinking anything and after using the restroom. 

Then I can weigh myself at night after a full day of eating and be up 3-4 pounds in the matter of a day.

So you might imagine how detrimental it can be for someone if they’re trying to lose weight but only weigh themselves a few times per month and at random times during the day.

Step 4: The Average Matters Most

Keep a running average of your calories and body weight during this 10-day period.

This is one of the best ways to know how much you’re actually eating, versus what you think you’re eating.

For a period of 10 days, you will do the following:

  • Step on the scale in the morning before drinking/eating anything and after you use the restroom. 

This process ensures you keep the conditions for an accurate weight measurement as accurate as possible.

  • Track every morsel of food in an app like Cronometer or MyFitnessPal and be as accurate as possible.

At the end of 10 days, you’ll have two pieces of data:

  • An average of your daily caloric intake (plus macro intake if you’re using an app like those mentioned above)
  • An average body weight measurement

Why Tracking Your Food *Really Matters*

It’s been shown in the scientific research that humans are notoriously terrible at accurately reporting how much we eat. What we perceive and what is actually happening are two different things altogether.

In this study, Discrepancy between self-reported and actual caloric intake and exercise in obese subjects, we see the following:

CONCLUSIONS: The failure of some obese subjects to lose weight while eating a diet they report as low in calories is due to an energy intake substantially higher than reported and an overestimation of physical activity, not to an abnormality in thermogenesis.

JC’s emphasis in bold

An example of this behavior is someone who swears up and down they’re eating 1500 calories per day. But when they’re required to accurately track for a few weeks, we’ll see they’re averaging much more than 1500 calories.

In this study, Normal weight men and women overestimate exercise energy expenditure, we get the following:

CONCLUSION: These results suggest that normal weight individuals overestimate EE (energy expenditure) during exercise by 3-4 folds. Further, when asked to precisely compensate for exercise EE with food intake, the resulting energy intake is still 2 to 3 folds greater than the measured EE of exercise.

JC’s emphasis in bold

I already mentioned this study above, but it bears repeating.

Calorie Deficit Recap:

1. Remember… a calorie deficit is created through increasing exercise or managing your calorie intake. Preferably, you’ll do both because that will enhance your results.

2. A caloric deficit is an absolute necessity for fat loss to occur. No one will lose weight without it.

Studies have shown people are more successful with their weight loss efforts when they have a program to follow, clear guides, and a support system to keep them in check. Want to make sure you succeed with your fat loss goals? Check out The Results Crew

You’ll want to read these next:

JC Deen is a nationally published fitness coach and writer from Nashville, TN. Currently living in the blistering Northeast. Follow me on X/Twitter