Is a calorie just a calorie? The answer is absolutely yes, or no, not at all. It depends on how you look at it. I explain in this post.
Is a Calorie Just a Calorie? Summary
- A calorie is a measure of how much energy is found in a food.
- In the lab, a calorie is just a calorie and can be calculated by burning food in a sealed container.
- In the body, a calorie is not just a calorie because calories from different foods require different enzymes and hormones to break down and use the nutrients.
- Food choices matter. Refined carbs create an environment inside your body that promotes fat storage, hunger, and cravings.
Is a Calorie Just a Calorie? [Video]
In this video, you’ll learn…
- The definition of a calorie.
- How calories differ depending on their environment.
- Food choices that will help you lose weight!
What is a Calorie?
A calorie is a measure of heat or energy. Specifically, it is how much energy is found in a food.
In the United States, the Calorie (with a capital “C”) reported on a package of food is actually a kilocalorie or 1,000 calories (with a lower-case “c”).
This might leave you scratching your head but ultimately simplifies things for you when you go to the grocery store while not denying the chemists the ability to dig deeper to get precise measurements. To those chemists, one kilocalorie is the amount of energy required to heat one kilogram of water by one degree Celsius.
They can calculate how many calories are in a food by burning the food in a sealed container surrounded by water. The higher the water temperature, the more calories the food contains. I tell you this because it provides the affirmative answer to our question: Is a calorie just a calorie?
In the lab, there is no doubt that the answer is ‘yes.’ A calorie is a measure of heat, so it doesn’t matter if you put a steak, a salad, or a loaf of bread into the sealed box when you burn it it will produce heat.
The Calorie is Just a Calorie Mindset
This ‘a calorie is just a calorie’ understanding is where we sat for a long time. It didn’t matter what we ate because we had adopted the lab’s definition of a calorie and applied it to our bodies. In fact, we took it even one step further. We not only considered calories coming in from food but also calories stored as body fat.
This is where we got the idea that – if one pound of fat contains 3,500 calories, then if I just eat fewer calories than my body needs, I will lose weight. For years, losing weight was a simple math problem with a simple solution. Eat less.
The thing is, this can work. When you create a big enough calorie deficit, your body will lose weight. And, it doesn’t matter where those calories come from.
Let’s look at an example using…
- 400 calories of steak
- 400 calories of leafy greens
- 400 calories of bread.
Even the most sedentary person will require more than 400 calories a day to run their basal metabolism. It doesn’t matter which of these foods you choose. If you eat it and only it daily, your body will lose weight. NOTE: Please don’t do that or think that I am recommending this as a way to lose weight. I’m not. Your metabolism will slow down.
But, we can use this example of eating different foods to provide the negative answer to our question of whether a calorie is just a calorie. While that statement is true in the lab, it is not true in the body.
In the lab, they burned food in a sealed container. Your body is not a sealed box with a flame inside. To your body, these foods may be equal in calories, but they are not equal in what it will take to break them down.
They contain different nutrients that require different enzymes and levels of hormones to get them digested, and the nutrients moved to your cells.
Why a Calorie is Not Just a Calorie
The steak from our example is made up of protein and fat and no carbs. The leafy greens are fat-free and mainly made up of non-starchy carbs with a small amount of protein.
The bread contains refined carbs, with a bit of protein and fat. Instead of 400 calories for an entire day, let’s change our example to look at what would happen if you ate one of these foods for lunch.
Calories from Steak
The 400 calories that get inside you when you eat the steak will create a digestive enzyme cocktail that slowly breaks down the protein and fat in the meat.
Once the nutrients are released, they will move into your bloodstream, where they can be picked up and use by your cells for energy or building and repairing structures.
Calories from Leafy Greens
It would certainly be a challenge to consume 400 calories of plain leafy greens for lunch. But this pile of greens contains the same number of calories as the steak and bread.
The calories from the greens are mainly carbs. Carbohydrates have more of an impact on your blood sugar and insulin levels than protein and fat. However, these carbs are from a whole, unrefined food.
The leaves will take a long time for your digestive system to break down, which slows the trickle of glucose into your bloodstream, providing you with a stable blood sugar level for a long time.
Calories from Bread
The 400 calories from the bread are mainly from refined carbohydrates. The milling and grinding required to turn the natural grains into refined bread make digestion happen quickly, causing a rapid influx of sugar into the bloodstream.
Food Choices Matter
Notice that the steak and greens are slow foods. They digest slowly and cause a slow and steady rise and fall in blood sugar. Because blood sugar is rising slowly, the energy from those foods remains available for hours.
That means that the calories from those foods come with some perks. When you eat them for lunch, hunger will stay away for hours, your energy level will be sustained at a comfortable level, and fat storage will be minimal because you have time to use up the energy.
The bread is a different story. The quick-digesting carbs from the bread cause your blood sugar to rise rapidly. The flood of sugar is followed by a rise of insulin to move the sugar out of your blood. Insulin not only encourages fat storage but also causes a rapid drop in blood sugar, causing you to feel hungry and low on energy sooner than you would have had you eaten the steak or greens.
When it comes to your body, calories are not just calories. Trying to trick your body by just eating less day after day will leave you hungry and has the potential to lower your metabolism. We also see that calories from different nutrients impact your blood sugar and insulin levels in different ways.
Eating a diet high in quick-digesting refined carbs encourages fat storage and causes unstable blood sugar, driving hunger and cravings.
I realize that getting on the path of healthy eating is a challenge. If you feel challenged when it comes to getting your eating to work for you, I encourage you to download my 0,1,2,3 strategy. It shares four daily habits that, when followed, help you stabilize your blood sugar, allowing you to control your weight and hunger.
Thank you for reading and have a wonderful week!
About the Author
Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.