What is the difference between a Calorie and a Kcalorie?

I had somebody ask me the other day what the difference between a calorie and a kcalorie was. That depends on if you are talking a calorie, or a Calorie (with a capital C). A kcalorie, or kilocalorie is equal to 1000 calories (small c). 1000 calories = 1 Calorie, or the term you are used to seeing on the nutrition label on the side of your cornflakes.

Simple, right? So, why the mixup in the terms?

In many countries across the world, companies that produce and package food products use the kcal on their nutrition label instead of the Calorie. Why? Well in scientific terms a calorie is the amount of energy that it takes to raise one gram of water one degree Celsius at 1 atmosphere.

Confused yet?

Yes, once upon a time scientists would actually take a measured amount of food substance and place it into a sealed container that was surrounded by a measured amount of water. The device was known as a bomb calorimeter. The food was completely burned and then the temperature of the water was measured. In this way they were able to determine the calorie (small c) content of the various macronutrients: carbohydrates – 4,000 kcals, protein – 4,000 kcals, fats/lipids – 9,000 kcals and even alcohol which is comes in at a whopping 7,000 kcals. Converted to Calories (big C) those are 4, 4, 9 and 7 Calories per gram.

So why does the US use Calories and the rest of the world use kcal on their nutrition labels? That’s a harder nut to crack. Why don’t we use the metric system with our tools like the rest of the world? I guess because we just like being different. It’s essentially the same thing but fewer letters to print and smaller numbers to work with. So unless you really want to get into the weeds with your nutrition just remember that 1 kcal = 1 Calorie.

Have a question or a comment?  Leave me a reply down below and I’ll try and bestow every ounce of knowledge on you as I can.  And if I have no knowledge on the subject you ask me about, I’ll make up a really good war story about my time in Korea.  Or you can email me your questions to Ron@fidelistraining.com  I look forward to hearing from you!