Calories 101

So what is a calorie, anyway?

We all know that we need to eat less calories to lose weight, and maybe we remember hearing something about them in High School Science, but most of us really have no idea.

The dictionary definition of a calorie is "an amount of heat exactly equal to 4.1840 joules" (dictionary.com). In fact, a calorie is simply a unit of measurement, not an actually tangible object.

When we talk about calories--in weight loss, or on nutrition labels--what we're talking about it the energy in the food that we take in.

Just so we're clear, calories are not bad. We rely on them--everything we do is powered by the calories we take in from food and beverages. Food is the fuel that runs our bodies, including our internal organs, and calories measure how much fuel we're getting. Some things, most notably soda and alcohol, are "empty calories"--they have no nutritional value, but still contain calories. That's why we avoid them during weight loss.

Calories are found in fat, carbohydrates, protein, and sugar. Not all of these are the same: fat contains twice as many calories as carbohydrates and protein.

The average amount of fuel (calories) needed to run a body for a day is 2,000. Keep in mind, this is an average which varies by gender, age, weight, and levels of physical activity.

When someone consumes more than the calories they need to run their body in a day, the excess calories are stored as fat. 3,500 unused calories equal one pound of fat.

So, if you consume 3,500 calories more than you need to run your body, you'll gain a pound of fat. If you consume 3,500 calorie less than you need to run your body, you'll lose a pound of fat. However, you don't want to do it all in one day. If you remember, 2,000 calories is the daily need, and to have 3,500 excess you would have to starve yourself and work out--not a good idea.

So, when you're losing weight, remember that every calorie counts!