Written by Christy Bacon, CSCS
When I ask my clients what a calorie is, I usually get a response like, “calories are what make us fat” or “I’m not sure, but I know that they are bad.” I see so many personal trainers give advice about how people should eat calories, but they rarely explain what a calorie is. The majority of people view calories negatively, which is unfortunate because we need calories in order to live. They give us energy to literally move throughout the day, and they even give our bodies energy to carry out all bodily functions that are vital to our survival. So if they are so important to us, then why do people seem to think that calories are so bad? This is a good question, and I will go into it as soon as we all understand what exactly a calorie is.
The best explanation comes from good ol’ Wikepedia:
The calorie is a unit of energy defined as the amount of heat needed to raise a quantity of water by one degree of temperature.
There are two versions of the unit in use, which has led to some confusion. It is historically defined as the amount of heat energy needed to raise the temperature of one gram of water by one degree Celcius. This is now known as the small calorie and is spelled with a lower case ”c”. Today it is most widely used in nutrition as the large Calorie, where it is spelled with a capital ”C” and is defined as the amount of heat needed to raise the temperature of one kilogram of water by one degree.
So if the small calorie or gram calorie (usually denoted cal) is the amount of heat energy needed to raise the temperature of one gram of water by one degree Celcius (or one kelvin), and the large calorie, food calorie, or kilocalorie (Cal, calorie or kcal) is the amount of heat needed to cause the same increase in one kilogram of water, then 1000 calories (cal) = 1 kilocalorie (kcal).
The take-home message? Calories are energy, and we need them in order to live and function.
So why is it that when everyone talks about calories, they talk about them as if people should try to avoid them? Calories are not the bad guy as long as there is a balance of calories consumed (eaten or drunk) versus calories burned (calories are burned through movement). Think of it as a scale. When you burn as many calories as you have eaten in a day, the body stays exactly on the weight it is at. If you EAT more calories than you have burned that day, your body will store the extra calories as fat. If you BURN more calories than you have eaten in a day, your body will go into its calorie storage (fat) and burn some of that. If you have many days in a row where you continuously eat more than you burn, you will go up in weight, and if you have many days in a row where you burn more calories than you eat, you will lose weight. This is the most basic and important aspect to our survival. Our body doesn’t know when its going to get energy again, for all it knows it could be days or weeks, so it saves all the calories (energy) it can. The scale is the key to our survival and to our weight control, it is just that simple.
There are two ways to affect this scale. You can influence it by controlling the amount of calories that you eat, and you can also influence it by controlling how many calories you burn. Unfortunately in this day of age, the majority of people choose to move as little as possible, which means that they can’t affect the scale so much by the amount of calories that they burn. They have to control the scale primarily by calorie consumption, and this leads to all sorts of issues with food control and yo-yo dieting. People become scared of calories and try to avoid them as much as they can.
The best way to influence the scale is to have a mix of burning calories through physical activity as well as control over how many calories are consumed. The more calories burned through physical activity, the more room you have to eat higher-calorie foods, which are generally the foods we like the most, and still have a balanced calorie scale.
Balance is the key to everything in life, even with calories! It’s our responsibility to control the scale so that our bodies can be healthy and happy.