With that said, let's talk about calories. They're at the top of every nutrition label and tip of everyone's tongue, and most people have absolutely what a calorie actually is. Yet that doesn't stop us from abiding by its rules, going along with blind faith as we slowly get fatter and fatter. So what is a calorie?
A calorie/small calorie/gram calorie, is nothing but a unit of measurement of energy(heat) that approximates the energy needed to raise 1 gram of water by 1˚C. However, this is not the measurement we use in terms of nutrition. For that we turn to to the kilocalorie.
A kilocalorie/big calorie/food calorie is the amount of energy needed to raise a kilogram of water by 1˚C, and is equal to 1,000 small calories.
Still, that doesn't tell us anything about how this applies to food. To this end, we can turn to the work of Wilbur Olin Atwater, who's Atwater System laid the ground work for our current reliance on calories as a measure of food energy. A very basic explanation reads as such: let's say a can of soda had a total of 200 calories. If we were to set the soda on fire and have it burn completely, it would create 200 kilocalories, enough energy to raise the temperature of 200 kilograms of water by 1˚C.
Now, I don't know about you, but I'm pretty sure I don't have an open flame in my stomach burning up the food I eat, and therein lies the problem. The human metabolism is a far more complicated system than a simple flame, and the best scientists in the world are still working on discovering what all the different biochemical taking place inside us actually do.
What has become clear in the past couple of years though, is that while calories may be a convenient way to measure a food's potential energy, it is far from accurate, and it should not be the foundation on which to build a healthy diet.
