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 more calories than you eat.
Simply, it’s about the "calories".
Therefore understanding calories and how they work can help you lose weight.
So let's start by defining what calorie is.
What Is a Calorie?
A calorie is a unit of measurement that has no size or weight.
It is actually a unit of heat energy. To be precise, it is the amount of energy it takes to raise 1 kg of water by one degree.
Also, energy in food and what’s stored by the body after it is consumed is considered calories. But not all foods contain the equal amount of calories. It differs per macronutrient: carbs, fats, proteins.
- Protein 4 calories per gram
- Carbohydrates 4 calories per gram
- Fat 9 calories per gram
Simply put, they are the energy found in the food, and their sources are carbs, fats, and proteins.
Although calorie deficiencies are needed for weight loss, we need calories to keep our body and brain functioning. It’s essential for our bodily functions.
In fact, they are our body’s readily available, primary fuel source. But when not utilized right away, they get conveniently stored either as fat or glycogen (carbs) for later use.
This is where your question of "how many calories are in a pound of body fat" comes in.
But before we get right to the answer, it’s important we debunk the popular myth on the "body fat".
Surprisingly or not, “body fat” is a commonly misunderstood word.
So, What is Body Fat?
Body fat is too often thought of as pure fat when it’s not.
If it is indeed pure, there are 9 calories in every gram, which amounts to a little over 4,000 calories per pound.
However, a pound of body fat is not pure fat.
It includes fat cells, which also contains some protein and fluids.
Therefore, the amount of calories body fat contains is less than if body fat were pure fat (1).
So how many calories does your body fat really contain?
Is It 3,500 Calories like Many Believe?
Let's find out.
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 (2).
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 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 body fat. Those they are only rough estimates.
Should I Still Cut Back 500-Calories A Day?
It is often recommended that to lose a pound a week, you need to cut back your daily calories by 500. All to create the 3,500 calories a week.
This is where the safe weight loss’s standard, 1 pound a week comes from.
But with a calorie deficit of 500 a day, it can overestimate the weight loss potential significantly and set dieters up for disappointment and failure. This is more so for the long-term weight loss.
That’s because as you cut back on calories and begin losing weight, your body will start to adjust to the new demands by burning fewer calories. Which naturally leads to more calories going to the fat storage than getting used up immediately.
In other words, weight loss cannot be put on an auto-pilot with a 500 calorie daily deficit. It's not a linear progression. Many experience plateau and slow down in the speed you lose weight (5).
The takeaway is the method of cutting back 500 calories daily overestimates the weight loss potential. It doesn't take in changes in your body and how fewer calories will be burned over time.
What To Consider When You're Trying to Lose Weight
Here is also another wrong assumption on weight loss.
When many try to lose weight, they mainly focus on losing the weight rather than body fat.
With a 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.
But there are steps you can take to prevent it. They not only minimize the chance of you losing your muscle mass but also help to build it, giving your metabolism a major boost.
1. Resistance training: Studies have shown that weight training which is a form of resistance training that is incredibly effective in reducing how much muscle mass you lose during the weight loss (6, 7).
Protein also shows effective at helping people lose weight. It’s also a nice addition that about 20-30 percent of the calories from protein get burned during digestion.
The takeaway here is a combination of resistance training and a higher protein intake have shown effective at preventing muscle loss and fostering fat loss.
Take Away Message
There are anywhere from 3,436 to 3,752 calories in a pound of body fat.
However, the common understanding that cutting back your daily calorie intake by 500 or (3,500 per week) can guarantee a weight loss of a pound a week.
It may work as a short-term solution, but eventually, your body will adjust to the new calorie intake and adapt by burning fewer calories, which inevitably slows down your metabolism and poses more challenges to your weight loss over time.