What Is A Calorie Deficit, And Is It The Best Way To Lose Weight?

Anyone who has attempted to lose weight before has likely counted calories but is perhaps unsure of what a calorie deficit is.

Perhaps you used a popular calorie-counting app like MyFitnessPal, where you record everything that you ate and drank in a day, or maybe you were less disciplined but still tried looking at the calorie count on the foods you were eating.

However, some people find that even when they are counting the number of calories they are eating and don’t see the numbers on the scale start to trend downward, their weight loss results are not as significant as they would like.

In general, to lose weight, it is not necessarily ideal enough to just consume fewer calories than you are already consuming. You need to create a calorie deficit. 

But what is a calorie deficit, and how much of a caloric deficit do you need to lose weight?

In this article, we will answer these questions, covering the basics such as the calorie deficit meaning, how to create a caloric deficit, and if you need to create a calorie deficit to lose weight.

We will cover: 

  • What Is a Calorie?
  • What Is a Calorie Deficit? Calorie Deficit Meaning
  • How to Create a Caloric Deficit
  • Do You Have to Be In a Caloric Deficit to Lose Weight?

Let’s dive in! 

A word jumble with words related to calories.

What Is a Calorie?

Before we cover what a calorie deficit is and how to create a caloric deficit, let’s do a quick primer on what a calorie is.

A calorie (or Kcal) is a unit of energy. One calorie is the amount of energy required to heat one gram of water by one degree Celsius. When discussing calories in food, the caloric content of food describes the amount of energy your body can get from that food.

Every type of food—and some beverages—contain a certain profile of macronutrients (carbohydrates, proteins, and fat), which are biological molecules that provide energy stored in the bonds between the atoms. 

As these bonds are broken down during the digestive process, energy is released.

Each of the different macronutrients provides a different amount of energy, or calories, per gram based on the arrangement of the atoms. Carbohydrates and proteins both contain 4 calories per gram, fat contains 9 calories per gram, and alcohol contains 7 calories per gram.

The body uses these calories for everything from keeping your heart beating and contracting your muscles to digesting food.

The word deficit.

What Is a Calorie Deficit? Calorie Deficit Meaning

Many people are familiar with the concept of a calorie deficit, even if they are unfamiliar with the term. So, what is a calorie deficit?

A calorie deficit, typically referred to as a caloric deficit, refers to the situation in which the number of calories you are consuming in a day, week, or another period of time is less than the number of calories you are burning over that same time period. 

For example, if you burn 2000 calories a day and you only eat 1500 calories, you have generated a 500-calorie deficit that day.

In general, to lose weight, you need to create a caloric deficit.

Most research has concluded that a caloric deficit of 3500 calories is enough to lose one pound of stored body fat. If you think about this over the span of one week, this works out to a daily caloric deficit of 500 calories.

A notebook that says calories, an apple, fork and measuring tape.

How to Create a Caloric Deficit

The only way to create a caloric deficit is to consume fewer calories than you are burning, which can also be thought of as burning more calories than you are eating.

Whether you think about this in terms of a microscopic time scale, such as your daily energy balance, or on a more macroscopic scale, like your weekly energy balance, the results will be the same: “the calories in” have to be less than the “calories out” over that time period.

With that said, it is important to distinguish that you can be in an energy surplus some days of the week (eating more calories than you are burning on those days) and still maintain a net caloric deficit over the course of the week, enabling you to lose weight.

Let’s consider a scenario of a 37-year-old man who has an average total daily energy expenditure of 2400 calories.

His week looks like the following:

  • Monday: Consumes 1800 calories
  • Tuesday: Consumes 2000 calories
  • Wednesday: Consumes 1800 calories
  • Thursday: Consumes 2000 calories
  • Friday: Consumes 1800 calories
  • Saturday: Consumes 1800 calories
  • Sunday: Consumes 3000 calories
A person putting calories into an app.

Even though he has a “cheat day“ on Sunday, he will still be in an overall caloric deficit for the week of about 2600 calories, putting him on track to lose 3/4 of a pound every week or 39 pounds per year.

Although creating a caloric deficit is simple in theory, it can be difficult to calculate your own “calorie math, “ and it is also difficult to put it into practice.

“Calorie math” essentially involves trying to accurately calculate both the number of calories you are eating in a day and the number of calories you are burning in a day so that you can make sure you are generating a caloric deficit rather than being in an energy balance or a caloric surplus.

When the number of calories you eat is equal to the number of calories you burn (energy balance), your weight will not change.

When you are in a caloric surplus, you are eating more calories than you are burning, and you will gain weight.

So, how exactly do you estimate the number of calories you are eating and burning?

It is a little easier to calculate the energy intake side of the equation as long as you are meticulous in recording all of the food and beverages you consume that contain calories and can accurately measure your portion sizes. 

An apple, calculator, and a notebook.

You can use the nutrition facts on the ingredients panel of the food product you consume to then calculate the number of calories in what you are eating based on the serving size.

When you consume foods that do not have a nutrition label, you can use online resources and food-tracking apps that have the nutrition facts for natural foods, restaurant meals, and other common foods that might not have a readily accessible label.

Calculating energy expenditure is a little more difficult, as there are four main factors that go into your total daily energy expenditure (TDEE): 

  • Your basal metabolic rate, which is the calories your body burns at rest just to keep your body alive. The American Council on Exercise reports that your BMR represents about 60-75% of the total calories you burn in a day, though it depends somewhat on how active you are both in terms of planned exercise as well as physical activity accumulated as you go about your day.
  • Calories burned during planned exercise, termed EAT, (exercise activity thermogenesis), which can be estimated using a heart rate monitor or a fitness watch such as the Garmin Forerunner 955 and the WHOOP 4.0
  • Calories burned during physical activity above baseline levels, termed NEAT (non-exercise activity thermogenesis).
  • Calories burned digesting food, termed the thermic effect of food.

You can estimate your BMR with online calculators such as the one here. Learn more about calculating your TDEE here.

You can also estimate your caloric needs here.

A variety of foods with their calorie count on them.

Do You Have to Be In a Caloric Deficit to Lose Weight?

Although the general consensus among health and fitness experts is that your overall energy balance—calories in vs. calories out—does play a major role in your weight loss, weight maintenance, or weight gain, some evidence suggests that calories aren’t the only thing that affects weight changes and fat loss.

According to the Centers for Disease Control and Prevention (CDC), cutting calories and getting 30 minutes of exercise daily is the most effective way to manage weight. Of note, the CDC reports that cutting calories doesn’t necessarily mean you have to eat less food. 

Focusing on volumetrics with your eating, which means trying to eat nutritionally dense but not calorically-dense foods, is the best way to feel satiated while cutting calories.

This involves eating lower-calorie foods that still fill you up, such as foods high in fiber and water. 

For example, consuming more vegetables and fruits instead of refined grains, packaged snacks, and sweets will fill your stomach up and keep hunger at bay even if the caloric content is less.

Finally, although the CDC does recommend creating a caloric deficit to lose weight, a deficit of no more than 3,500-7,000 calories per week—which would yield 1-2 pounds of fat loss—is the suggestion for effective and sustainable weight loss. 

Again, the suggestion is to generate this caloric deficit through a combination of dietary limitations and daily physical activity.

If you are also looking to add some exercise to your weekly fitness routine to help with your weight management, check out our guide to 16 Fun Cardio Ideas to spice up your daily workouts!

A watch with calories on it.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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