menu iconknow your dna logosearch icon
What is a Calorie Deficit Diet?
Updated on August 29, 2023
Back to top
back to top icon
Diet / Weight Loss
What is a Calorie Deficit Diet?
KnowYourDNA is reader-supported. This means we may receive a commission when you buy something from one of the links on this page.

For years, many weight-loss programs have been based on calorie counting. It’s also linked to a weight loss regime called the calorie-deficit diet.

At its core, the calorie-deficit diet doesn’t include a list of foods you should or should not eat.

Instead, it considers your calorie intake or the amount of energy your body gains from breaking down foods.

You can achieve a calorie deficit by reducing your calorie consumption, adding more physical activities, or doing both.

What is a Calorie Deficit Diet? 2

What are Calories?

Calories are a unit of energy. They’re how we measure how much energy we obtain and burn from different foods. 

Food and drinks provide calories that your body processes into glucose, which becomes its primary energy source.

To fully function, the body requires a certain amount of calories daily. Many factors influence your daily calorie needs, such as age, sex, and level of physical activity.

The US Dietary Guidelines mentioned that healthy adults aged 21 and up should consume between 1,600 and 3,000 calories daily.

The recommended calorie intake for biological adult women is 2,000 calories per day, while it’s 2,500 for biological adult men.

Sources of Calories

Calories come from three sources: carbohydrates, protein, and fats. These macronutrients have different calorie counts per gram. Your body processes them at varying rates, too.


Carbohydrates (carbs) are the body's primary source of energy. Your body breaks down carbs into glucose, which it uses shortly for energy.

The excess glucose is stored in the liver and muscles for later use.

The body metabolizes carbs faster than the other macros. They provide a fast supply of energy that makes them useful when you’re doing high-intensity physical activities.2

Carbs provide four calories per gram.2 Healthy sources of carbs include:

  • Whole grains like brown rice, oats, and quinoa
  • Starchy vegetables like potatoes, sweetcorn, sweet potatoes
  • Lentils and beans


Protein is an essential macronutrient made from chains of amino acids linked in a complex order. Your body takes longer to break down proteins, so it does tend to be a slower supplier of energy compared to carbs.

They are, however, a more sustainable source of energy. They can serve as a backup energy source when there’s a short supply of carbs.

Proteins are essential for various bodily functions. They help with tissue repair and muscle growth.

Protein provides four calories per gram.2 Healthy sources of proteins include:

  • Lean meat and poultry
  • Fish 
  • Eggs
  • Tofu
  • Nuts and seeds, like pine and almond
  • Dairy products, like milk, yogurt, cheese, and other alternatives


Fats are the slowest sources of energy. This is because they take the longest to break down.

However, it’s also the most energy-efficient and calorie-dense macronutrient. Each gram of fats provides nine calories.2 

The body deposits extra calories as fats, typically in the abdomen and under the skin. The body can use these stored fats later when it needs more energy.

Healthy sources of fats include:

  • Fatty fish, such as tuna, mackerel, and salmon
  • Eggs
  • Avocado
  • Nut and seed butter
  • Olives and olive oil
  • Tofu

What are the Benefits of a Calorie-Deficit Diet?

A calorie-deficit diet can benefit your health in many ways. 

Helps in healthy weight loss

A calorie-deficit diet includes eating fewer calories than your body’s maintenance caloric needs.

It’s a lucrative weight loss strategy that many use. It makes weight management a little easier as you don’t have to do too much planning, just limiting consumption.

Consuming fewer calories makes your body turn to your fat reserves for energy, leading to a decrease in body fat.3

It also helps lower your risk of weight-related problems like obesity.

Improves insulin sensitivity

Research shows that a caloric deficit can help improve your body’s sensitivity to insulin, potentially lowering the risk of diabetes.4

Insulin is a hormone that helps your body process glucose for energy.

Increased insulin sensitivity allows your cells to absorb glucose more efficiently, which can help lower your blood sugar levels.

Reduces inflammation

Studies show that following a calorie-deficit diet helps reduce inflammation in the body.5 Inflammation is typically short-lived and happens when there’s an injury or infection.

However, it can also be chronic or long-term. Long-term inflammation can cause chronic illnesses, such as heart disease and cancer.

A caloric deficit diet can help fight inflammation and reduce chronic disease risk in many ways.

For instance, it can cause weight loss, which lowers the amount of fats in your body. Fat cells create pro-inflammatory molecules, so lowering your body fat can help reduce inflammation.6

Calorie restriction may also aid in lowering inflammation by promoting antioxidant production.7 Antioxidants are chemicals that can ward off the harm caused by free radicals.

Free radicals are unstable molecules that are byproducts of normal cell metabolism. They are linked to chronic inflammation and diseases.

Increasing evidence shows that calorie restriction may help the body fight inflammation. 

Calorie-deficit diet can potentially lower your risk of chronic conditions, including diabetes, cancer, and heart disease.

Improves cardiovascular health

Research demonstrates that eating fewer calories through a calorie-deficit diet can help improve your cardiovascular health. 

It’s because a caloric deficit can help you lose weight, which can also reduce your body fats. 

Fat cells (adipocytes) can produce molecules that can trigger aldosterone production. Aldosterone is a hormone that, when in excess, can raise your blood pressure.8 

It’s why exerting effort to lose weight and reduce body fat can benefit your blood pressure.

Potential Risks of Calorie Deficit 

The calorie-deficit diet comes with minimal potential risks, including the following:

  • It can slow down your metabolism — When you reduce your calorie consumption, your body enters starvation mode and tries to conserve energy. As a result, your resting metabolic rate (RMR), or the number of calories your body burns when at rest, may decrease.9
  • It can cause muscle loss — A loss in muscle mass can likely occur if your calorie-deficit diet is low in protein or you don’t combine it with exercise. 
  • It can cause nutritional deficiencies — If you aren't mindful, cutting calories can leave you lacking essential nutrients. You may also have less nutrient intake when you consume fewer calories.

Creating a calorie deficit can be effective for weight loss, but you should be mindful of the risks involved. 

Some measures to minimize these risks include getting enough protein, regular exercise, and taking a vitamin or mineral supplement

Calculating Your Daily Calorie Intake

Knowing your recommended daily calorie intake can help you with weight loss. But it’s also helpful if you’d like to gain weight or maintain it.

To calculate your daily calories, you need to get your basal metabolic rate (BMR), or your body’s rate of metabolism while at rest.

BMR is the minimum energy needed to support vital functions like breathing, digestion, and blood circulation.

The Harris-Benedict formula is one approach to estimating your BMR. It can calculate a ballpark figure for how much energy your body uses each day at rest.

Step 1: Determine Your BMR

  • For women: BMR = 655.1 + (9.563 x weight in kilograms) + (1.850 x height in centimeters) - (4.676 x age in years)
  • For men: BMR = 66.47 + (13.75 x weight in kilograms) + (5.003 x height in centimeters) - (6.755 x age in years)

Step 2: Calculate your Total Daily Energy Expenditure (TDEE)

The next value you must calculate is your total daily energy expenditure (TDEE). 

It refers to the energy your body uses daily, quantified in calories. TDEE factors in both your BMR and your level of physical activity.

To compute your TDEE, you must multiply your BMR with an assigned value representing your activity level.

  • Sedentary (little or no exercise): BMR x 1.2
  • Lightly active (exercise 1 to 3 days a week): BMR x 1.375
  • Moderately vigorous (exercise 3 to 5 days a week): BMR x 1.55
  • Active (exercise 6 to 7 days a week): BMR x 1.725
  • Very active (hard exercise 6 to 7 days a week): BMR x 1.9

It’s essential to note that your actual BMR and TDEE may vary from the values shown by the Harris-Benedict formula since they’re just estimations.

If you want to maintain your current weight, you should limit your consumption within your TDEE. Aim for eating more calories than your TDEE if you're planning to put on weight.

How Many Calories Should I Eat In A Calorie Deficit?

Once you get your TDEE value, you can determine how many calories you should eat to create a calorie deficit by subtracting a certain number of calories from your TDEE

The number of calories you subtract will depend on how much weight you want to shed. Most people start by cutting down 500 calories in their daily intake. 

According to nutritionists, a calorie deficit of 500 calories can help you lose ½ to 1 pound per week.10 

The Dietary Guidelines for Americans recommend that healthy adults eat 1,200 to 1,500 calories daily for a deficit.1

However, without the supervision of a health expert, a woman's daily calorie consumption should not go below 1,200, and a man's should not go below 1,500.11 

Consuming too few calories can be detrimental to your health because it might deprive your body of needed nutrients. 

Do You Need to Count Calories to Reach A Deficit?

Calorie counting involves measuring the calorie content of your food before you eat. 

While it’s helpful to track the calories you consume each day, it’s not that necessary when trying to lose weight.

You can still hit your weight loss goals without counting calories. Eating foods that have a low-calorie density is vital. 

Low-calorie-dense healthy foods include:

  • Fish
  • Fruits 
  • Egg whites 
  • Vegetables 
  • Whole grains
  • Lean meat and poultry

These foods fill you up without drastically increasing your calorie consumption. You’re less likely to overeat since they keep you satiated.

How to Achieve a Calorie Deficit Safely

You don’t have to remove that many calories from your diet to get started. In the beginning, consider cutting your calorie consumption by a smaller amount. 

Think of it this way, each time you decrease your calorie consumption, it brings you closer to your goal. 

For instance, if you’d typically eat 3,000 calories daily, try bringing that down to 2,800 calories. You can gradually reduce it till you hit your goal of 1,500 calories

Remember that you should ensure you’re meeting your nutritional needs even with a calorie-deficit diet. 

Talk to your doctor before going on a calorie deficit so you can discuss if it’s a safe and suitable approach for you.

Here are some of the ways to start a calorie deficit safely.

Change Your Diet

Many people who struggle with weight problems are most likely consuming too many calories than their body needs daily. 

When you get more calories than necessary, your body stores the excess as fat. This can lead to weight gain over time.

Cutting down on your calories helps you burn fat and makes you lose extra weight. Here are some tips on how you can lower your calorie consumption.

  • Eat smaller portions
  • Focus on eating low-calorie but nutrient-dense foods, like vegetables, fruits, and unprocessed whole foods
  • Minimize consuming processed foods, sugary beverages, and unhealthy fats
  • Prioritize lean proteins, such as chicken, fish, and beans

Plan your meals

Planning your meals can also help you reach a calorie deficit. It allows you to portion your food and reduce your daily calories. 

You can use meal planners if you don’t have time to plan meals. These are apps that create customized meal plans based on your preferences and current health.


Exercise and physical activity can also help you reach a calorie deficit. 

If you’re trying to lose weight, you may want to spend more time with an exercise routine. The right amount of exercise burns more calories than you consume. 

Here are some simple physical activities to try and how many calories you can burn doing them:12

  • Jogging burns 180 calories in 30 minutes
  • Walking burns 135 calories in 30 minutes
  • Swimming burns 180 calories in 30 minutes

How Long Should You Be In A Calorie Deficit?

Everyone’s weight loss journey is different. There’s no definite timeline for how long you should be in a calorie deficit.

Some people get results a few months later. Others take years to hit their goals. Your current weight, target weight, body type, and health status will help determine your needed time

You may stop as soon as you reach your goal weight. Healthy eating will help you maintain your results.

Updated on August 29, 2023
Jennifer Anyabuine
Jennifer Anyabuine
Content Contributor
Jennifer Anyabuine is a content writer with KnowYourDNA. She has a B.S. in Biochemistry. She has been writing for 2 years. Her focus is women’s health, fitness, mental health, and general wellness.
Back to top icon