How Many Calories Are in a Pound of Body Fat?

How Many Calories Are In a Pound of Fat

Does a pound of fat equal 3500 calories?

To lose one pound of body fat, you need to burn off 3500 calories above what your body needs (1).

This is your calorie deficit.

Weight loss is directly related to the number of calories that goes in and out of your body.

To lose weight, you either have to take in fewer calories than you burn or burn off more calories than you eat.

Frankly, it’s about “calories”.

Therefore, understanding calories and how they work in your body can help you lose weight.

In this article, we’ll explain how many calories are in a pound of body fat.

We’ll also take a quick look at the daily 500-calorie deficit theory. And more importantly, how more realistically and accurately we can predict your weight loss potential. 

With that said, let’s start by defining what calorie is

What Is a Calorie?

A calorie refers to the energy found in food and what is stored by the body after it gets consumed. 

Your body has a constant need for energy from food in order to keep functioning. 

Everything you do is fueled by energy whether it’s sitting, walking or sleeping.

But not all foods contain an equal amount of energy (calories). It differs per macronutrient: carbs, fats, and proteins.

for example:

  • Protein – 4 calories per gram
  • Carbohydrates – 4 calories per gram
  • Fat – 9 calories per gram

Calories consumed either get stored as body fat or converted to energy as glycogen to fuel the body. 

What Is Body Fat?

Body fat is too often thought of as pure fat when it’s not. 

It is in fact made up of fat cells that contain proteins and fluids along with fat itself. 

This dilutes the body fat’s fat content. Naturally, this also means there are fewer calories found in body fat than pure fat. 

There are 9 calories per gram of pure fat, which equates to about 4,100 calories per pound. 

The number of calories in body fat would be less than this amount (2).

So how many calories does your body fat really contain? 

How Many Calories Are In a Pound Fat

The idea that every pound of body fat contains 3,500 calories actually dates back to 1958. It was first introduced by Max Wishnofsky, a scientist from that time (3).

Based on the scientific evidence available back then, he concluded 3,500 calories is what’s equivalent to body fat by the pound. 

This inevitably created the myth that 500-calorie reduction a day leads to 1 pound of weight loss a week.

Half a century later, this figure is still being quoted frequently even in the scientific literature. 

It’s to the point that it’s understood as common knowledge.

But since we want to get to the bottom of it, let’s do our own math to find out. 

Generally speaking, we can assume the following values:

  • 1 pound = 454 grams
  • 1 gram of pure fat= 8.7 ~ 9.5 calories 
  • Fat tissue = 87% pure fat

Based on those numbers, a pound of body fat equals to 3,436 – 3,752 calories.

Though they are not definite by any means. The amount of fat content may differ across varying types of body fat, keeping those calorie figures fluid. 

The bottom line here is that there are 3,436 to 3,752 calories in a pound of fat. Those are only rough estimates. 

The 500-Calories Deficit A Day Issue

A common recommended ‘myth’ is that if you consume fewer than 500 calories a day or 3,500 fewer in a week, you will lose a pound of fat per week. 

This equals 4 pounds a month and 12 pounds in 3 months. 

This is where the safe weight loss’s standard, one pound a week comes from.

But is this how it really works?

The deficit of 500 calories a day ideology tends to grossly overestimate the weight loss potential. (4, 5, 6). 

To start, it doesn’t account for the body’s changing body composition. As you cut back on eating and consume fewer calories, your body will adjust to use less energy to function. 

It’s your body’s response to the new supply level. This metabolic change is referred to as “adaptive thermogenesis”. It’s your body in a starvation mode where it shifts its focus to the preservation of energy to combat fewer calorie intake. 

It’s a natural course of weight loss and should be expected. It shows weight loss is not a constant or steady linear process. Or it’s not a goal you can put on auto-pilot with one setting. 

More Accurate Weight Loss Tools

Thankfully, there are many weight loss tools and apps these days. Many are well equipped to help you predict a more accurate weight loss trajectory. 

There are two in particular that are particularly helpful. 

One is from the Pennington Biomedical Research Center. Single Subject Weight Change Predictor is a good example of a tool that’ll help you predict your weight loss more accurately. 

It’ll take your current diet as well as exercise to come to their realistic assessment. 

The National Institute of Health also developed a tool called The Body Weight Planner. It shows the number of calories you need to lose weight and maintain. 

It also accounts for your body’s adaptability to the fewer calorie intake. This helps you stay close to more realistic and accurate weight loss prediction.

What to Consider When Trying to Lose Weight

While it’s true eating less will help you lose weight, the weight you lose won’t just be pure fat.

With much emphasis on losing the actual weight, it comes at the cost of losing muscle mass. And when your muscle mass is lost, it becomes that much harder to lose weight.

It’s a counterproductive cycle you want to avoid.

Since muscles are metabolically active than fat, you want to perverse your muscles as you lose body fat. This is because muscles use more energy in the form of calories.

What this means is that the more lean muscle mass you have, the more calories you’ll burn.

So it makes sense to have as much muscle mass you possibly can (7).

Luckily, there are several ways you can preserve and even build your lean muscle. 

  • Weight Lifting: Lifting weights is shown to prevent muscle loss. It also helps build muscles, which increases the calories your body burns. 
  • High-protein diet: Diet high in protein helps prevent your body from breaking down the muscles. 

By combining both strategies, you can help preserve your muscle mass and even build some more. 

The Takeaway 

There are 3,436 to 3,752 calories in a pound of body fat.

However, it’s a common understanding that cutting 3 500 calories a week can somehow lose a pound a week of weight loss. 

It’s a misconception that can potentially lead to disappointment. 

It may work in the beginning, but eventually, it’ll come to a halt when your body adjusts to the new, fewer calorie intake. 

To continuously lose weight, you must frequently assess your calorie needs. Adjust your weight loss approach as you progress. It’ll ensure your continuous weight loss and help you ultimately reach your goal. 

References:

  1. Hall, K D. “What Is the Required Energy Deficit per Unit Weight Loss?” International Journal of Obesity (2005), U.S. National Library of Medicine, Mar. 2008, www.ncbi.nlm.nih.gov/pmc/articles/PMC2376744/.
  2. Martin, A D, et al. “Adipose Tissue Density, Estimated Adipose Lipid Fraction and Whole Body Adiposity in Male Cadavers.” International Journal of Obesity and Related Metabolic Disorders : Journal of the International Association for the Study of Obesity, U.S. National Library of Medicine, Feb. 1994, www.ncbi.nlm.nih.gov/pubmed/8148928.
  3. Thomas, Diana M, et al. “Time to Correctly Predict the Amount of Weight Loss with Dieting.” Journal of the Academy of Nutrition and Dietetics, U.S. National Library of Medicine, June 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC4035446/.
  4. Hall, Kevin D, et al. “Quantification of the Effect of Energy Imbalance on Bodyweight.” Lancet (London, England), U.S. National Library of Medicine, 27 Aug. 2011, www.ncbi.nlm.nih.gov/pubmed/21872751.
  5. Thomas, D M, et al. “Can a Weight Loss of One Pound a Week Be Achieved with a 3500-Kcal Deficit? Commentary on a Commonly Accepted Rule.” International Journal of Obesity (2005), U.S. National Library of Medicine, Dec. 2013, www.ncbi.nlm.nih.gov/pubmed/23628852.
  6. Hall, K D. “What Is the Required Energy Deficit per Unit Weight Loss?” International Journal of Obesity (2005), U.S. National Library of Medicine, Mar. 2008, www.ncbi.nlm.nih.gov/pubmed/17848938.
  7. Chaston, T B, et al. “Changes in Fat-Free Mass during Significant Weight Loss: a Systematic Review.” International Journal of Obesity (2005), U.S. National Library of Medicine, May 2007, www.ncbi.nlm.nih.gov/pubmed/17075583/.
Misato Alexandre

Co-Founder

After making healthy living a priority, Misato lost over 20 lbs in less than 90 days. Instead of weight loss being a dreading experience, living the lifestyle of health and fitness granted her more happiness and joy than ever before. She co-founded Fitwirr to make health and fitness simple for everyone and share her tips through writing evidence-based articles on nutrition, weight loss, and exercise.

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