Calorie Deficit for Losing Weight

calorie deficit for weight loss

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When you take in fewer calories than you burn, you create a calorie deficit. This is also sometimes called an energy deficit because calories are a unit of heat or energy. Regardless of the terminology, a caloric deficit is an important part of losing weight.

It should be noted, however, that not all nutrition experts or researchers agree that shedding excess weight is as simple as cutting a certain number of calories per day. Here we explain more about calorie deficits and how to keep realistic weight loss expectations when reducing your food intake.

Calories—Basic Facts

A calorie is a unit of energy. It is the amount of heat needed to raise the temperature of one gram of water by one degree Celsius. Calories in food provide energy in the form of heat so our bodies can function even when they are at rest.

The total number of calories you burn each day is called your total daily energy expenditure or TDEE. When TDEE is calculated, it includes:

  • Calories burned through exercise and non-exercise movement
  • Calories burned during digestion, called the thermic effect of food or TEF
  • Calories you burn to maintain basic bodily functions, such as breathing and blood circulation

To figure out how many calories your body needs to perform basic functions, you can estimate your resting metabolic rate (RMR). Once you know your RMR, you can use a calculator to estimate your total daily energy expenditure. You can also get tested in a lab setting or health club.

What Is a Calorie Deficit?

If you take in fewer calories than your body needs to perform all of its necessary functions, you create a calorie deficit. For instance, if you use 2,000 calories today but only take in 1,800, you have a deficit of 200 calories.

When a calorie deficit exists, your body gets energy or fuel from stored fat. In this case, stored fat is stored energy. Your body can use it to keep moving instead of using energy from food. When your body burns fat for energy, you lose weight.

Calorie Deficit for Weight Loss

As mentioned previously, there are differing opinions as to calorie deficits and how they contribute to weight loss that is healthy and sustainable.

The 3500-Calorie "Rule"

Some nutrition-based organizations suggest that you need a calorie deficit of 3500 calories per week to lose one pound of fat. For instance, the National Institute of Health suggests cutting 500 calories per day to achieve this goal.

Research suggests that the notion of there being 3500 calories in a pound of fat dates back to the 1950s, when Max Wishnofsky, a New York doctor, wrote this in a report. Since that time, many top health officials and agencies have continued to echo this statement.

If you've ever tried to lose weight by cutting calories, then you may have experienced these effects yourself. However, there are many opponents of this ideology who say that losing weight isn't as simple as creating a specific calorie deficit.

Calorie Deficits Aren't That Simple

In an article published by the International Journal of Obesity, researchers explain that the idea of a 3500-calorie deficit resulting in the loss of one pound of fat "grossly overestimates actual weight loss."

They back this up with several studies where subjects reduced their caloric intake by a certain amount each day, yet lost significantly less weight than predicted under the 3500 calorie rule. Based on their findings, they concluded that losing weight is more of a curve than a line.

In other words, even though subjects continued to eat fewer calories than they expended, their weight loss started to taper off versus continuing at its initial rate. Some dietitians agree, adding that several factors affect weight loss, from gender to exercise habits and more, and calorie deficits are only one.

The Bottom Line

One thing that most experts seem to agree on is that a calorie deficit can assist with weight loss. However, the amount that it is able to help varies based on a variety of factors. Keeping this in mind can help you maintain realistic expectations when trying to lose weight.

How to Create a Calorie Deficit

While it seems simple to create a calorie deficit and lose weight, many people struggle with the process because it's not as easy as it seems. The good news is that you don't have to starve yourself with a fad diet or juice fast. In fact, there are three healthy ways to create a calorie deficit for weight loss.​

Eat Less Food

If you cut your portion sizes, cut back on snacking, and choose lower-calorie foods at mealtime, you'll consume fewer calories each day. Reduce your caloric intake enough and you'll create a calorie deficit that is large enough for weight loss.

Get Active

The number of calories your body needs each day depends on your activity level. This includes the exercise you do and also your non-exercise physical movement. If you increase the number of calories your body needs but still consume the same number of calories from food, you'll have a calorie deficit. 

Combine Diet and Exercise

Studies have found that, although both diet and exercise can help with short-term weight loss, the best way to maintain weight loss long-term is by combining them. Taking this approach creates a calorie deficit in two ways, providing optimal results.

A Word From Verywell

If you've set a goal to slim down, you'll find countless plans on the market that promise to provide results without counting calories or reducing your food intake. But every plan must create a calorie deficit to some degree in order to be effective long-term.

Most of the plans that sidestep calorie counting help you make lower-calorie food choices or time your meals so you consume less. In short, they are just creative ways to reach the same outcome. Sometimes they work, but often they don't.

Keep in mind that you don't need to spend money on expensive programs to slim down. Create your own calorie deficit by setting small goals and making small changes throughout the day.

You can also get help from a registered dietitian. These professionals can design an effective meal plan that meets your personal needs. Over the long term, a plan that is created based on your individual needs is usually a plan you are most likely to stick to.

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6 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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