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A calorie deficit is when a person consumes less calories than they burn. A person’s individual health and circumstances will affect their calorie needs.

A person can create a calorie deficit by consuming fewer calories than they need to maintain their body weight. Over time, this calorie reduction can lead to weight loss.

There is no single calorie deficit value that will ensure weight loss in all people. However, in many cases, a consistent 500-calorie daily deficit will roughly equate to 1 pound (lbs) of fat loss per week.

This article covers everything people need to know about calorie deficits and weight loss.

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A calorie deficit occurs when the number of calories a person consumes daily is smaller than the number of calories they burn.

The body needs to burn a certain number of calories to perform all its functions each day.

How many calories a person needs each day varies based on their:

  • sex
  • age
  • physical activity levels
  • height
  • weight
  • body composition

Here are some estimated calorie needs for adults aged 19 years and over:


A person can create a calorie deficit by reducing the number of calories they eat, increasing their activity levels, or both.

There are several ways to determine how many calories a person normally burns daily.

For example, they can opt to calculate their daily calorie needs manually or find an online calculator.

To perform a manual calculation, moderately active people can multiply their current body weight by 15 to estimate how many calories they would need each day. Anything less than this is a deficit.

Basal metabolic rate

A person can also use their basal metabolic rate (BMR) and activity levels to determine their current caloric needs. They can use one of the following formulas to determine their BMR, according to their sex:

  • adult male: 66 + (6.3 x body weight in lb) + (12.9 x height in inches) – (6.8 x age in years) = BMR
  • adult female: 655 + (4.3 x weight in lb) + (4.7 x height in inches) – (4.7 x age in years) = BMR

Once a person has their BMR, they can use one of the following formulas, based on their activity levels, to determine their caloric need:

  • Sedentary: little or no exercise = BMR x 1.2
  • Minimally active: 1–3 days per week of exercise or activity = BMR x 1.375
  • Moderately active: 3–5 days per week of moderate activity or sports = BMR x 1.55
  • Very active: 6–7 days per week of hard exercise = BMR x 1.725
  • Extra active: athletes who train twice per day, for example = BMR x 1.9

People can also ask their doctor or nutritionist for the most accurate caloric intake estimates. These professionals can tailor the estimate based on the person and their lifestyle.

Once a person knows how many calories they need each day or week, they can work on creating a calorie deficit.


One component in creating a calorie deficit is changing what a person eats and drinks daily. A person should focus on foods that are rich in nutrients but low in calories.

According to the Dietary Guidelines for Americans 2020–2025, a healthful eating pattern with fewer calories should include:

  • whole vegetables
  • whole grains
  • whole fruits
  • lean proteins
  • low fat or fat-free dairy, including milk, yogurt, cheese, or fortified soy beverages
  • ‘healthy’ oils such as olive or canola

A person should also avoid consuming sugary drinks and trans fats.


An important part of weight loss is exercise. An inactive person should try to increase their daily activity levels if they can.

The Centers for Disease Control and Prevention (CDC) recommends 150 minutes of moderate activity and two sessions of strength training per week to maintain a moderate weight. The more physically active a person is, the more calories they will burn. This increases the number of calories they need, making creating a deficit easier.

This can include activities such as:

  • walking
  • taking the stairs instead of the elevator
  • hiking
  • playing sport
  • biking

Plainly, a calorie deficit is essential to lose weight. However, this may not occur consistently, and many factors can impact weight loss progress.

When reducing calorie intake, hormonal changes, water retention, and alterations in fat storage can cause people to stay the same numerical weight. However, this does not mean that a person is not experiencing body composition changes.

Cutting calories is an important part of weight loss, but it is not the only consideration to make.

  • Calorie counting risks: Counting calories is not always necessary for weight management, and, in some cases, it may be counterproductive or harmful.
  • Activity benefits: Increasing activity levels has numerous benefits aside from weight management. Strength and cardiovascular training can improve joint health, bone density, and heart function and boost mood.
  • Dietary consideration: A person must maintain adequate nutritional intake when reducing overall calories. Limiting food intake can lead to harmful nutritional deficiencies if conducted incorrectly.

People should avoid cutting too many calories. Cutting out about 500 daily is a good range to aim for. People should also avoid losing more than 2 lb each week.

If a person cuts too many calories and does not get enough necessary nutrients, they can experience some health problems.

The body needs a minimum number of calories to function properly. Cutting too many can increase the risk of health issues, including:

  • not getting enough nutrients, which can interfere with gaining or maintaining bone mass
  • depriving the brain of necessary energy
  • decreasing metabolism
  • increasing the risk of developing gallstones

Some symptoms of not consuming enough calories include:

  • getting sick frequently
  • being unable to lose weight
  • experiencing negative changes in mood or behavior
  • having difficulty sleeping
  • experiencing constipation

Before cutting calories, a person should talk with their doctor or nutritionist. People with specific health conditions, such as diabetes, may need specialized diets to help them manage their condition.

Below are frequently asked questions relating to calorie deficits.

How do I figure out my calorie deficit?

A calorie deficit is the sum of a person’s energy expenditure minus their energy intake. Some online calculators can help to estimate this.

Is a 1,200 calorie deficit good for weight loss?

A 1,200 calorie deficit can lead to weight loss. However, large calorie deficits, or sudden changes in them, can lead to adverse health effects and may even result in long-term weight gain.

How much of a calorie deficit does a person need to lose 1 pound?

A calorie deficit of 500 calories may be enough for a person to lose 1 pound over a week. However, various factors can influence weight loss, including weight, activity level, health conditions, and more.

How much calorie deficit is safe for weight loss?

A person’s age, sex, weight, and many other factors can affect their calorie needs. However, aiming for a daily calorie deficit of approximately 500 calories is often a good starting point for weight loss.

Creating a calorie deficit may be helpful if a person wishes or needs to lose weight. A person can do this using a combination of diet and exercise.

They should try to focus on eating highly nutritious foods, drinking more water, and exercising regularly.

Formulas and online calculators are available to help people estimate how many calories they burn per day. From there, people can estimate how many calories they should eat to create a calorie deficit.

A person should aim to lose no more than 1–2 lbs per week to avoid potential health issues associated with insufficient nutrients.