What is a Calorie

Everyone has heard of them; you know you are supposed to count them, whatever that means; you know they have to do with food but you just aren’t sure exactly what, most of us are trying to cut back on them to lose weight and frankly you are quite sick of hearing about them. But, what are these little guys and why do they seem to affect our lives so much in terms of how much we weigh?

In its most technical terms a calorie can be defined as a unit of measurement that is used to indicate the potential amount of energy provided to the body by a particular food. Also known as kilocalories (= 1000 calories), which the amount of energy that is needed to raise the temperature of 1 kilogram of water 1 degree Celsius. A calorie can be considered just a unit of energy. In most cases we associate calories with food but the truth is that they can apply to anything that contains energy. An example of this is gasoline. There are approximately 31,000,000 calories in 4 litres (gallon) of gasoline. This is equal to eating roughly around 64,000 Big Macs from McDonalds.A calorie is equal to approximately 4.2 joules of energy, a common unit energy used in the science world.

In our society we often think of calories in terms of their relation to food. Such as “This chocolate bar has 300 calories.” In actuality the calories that are located on food packaging are actually kilocalories. So this “300 calorie” chocolate bar contains 300,000 regular calories or 300 kilocalories. In a similar fashion, when dealing with exercise and burning off calories, when someone says “You burned off 100 calories doing that exercise.” they are talking about kilocalories.

Now that we have some idea of what calories are, let’s take a look at what they do. As humans we rely on energy to survive. We need energy for every function we perform; even breathing, and for pumping blood as examples. And the energy we use for this we acquire from food, in the form of the almighty calorie. When you think of food in terms of calories, always remember that this is a representation of the amount of potential energy that food possesses. Both Carbohydrates and Proteins contain 4 calories per gram and Fat contains 9 calories per gram, meaning that fat has more energy per gram. These three building blocks are what making up food and if we know how much of each is contained in what we are eating we can easily convert this to how many calories, or energy, we are consuming.