What Is a Calorie?

Most people have heard about calories and read on the nutrition label how many are in a particular food, but do people really know what a calorie is, how it is used by their body, or how many they should have in a day? Sadly, most do not.

A calorie defined

In its simplest form, a calorie is a unit of energy; in Medilexicon’s medical dictionary a calorie is defined as “The amount of heat necessary to raise 1 gram of water 1 degree Celsius.” Because a calorie is a measure of heat, it occurs in many other things besides food; for example, 1 ton of coal contains 7,004,684,512 calories. However, when referring to it in the realm of nutrition and fitness, it is a unit of measure regarding how much energy we consume through food and drink and the number of units we burn up through normal bodily functions and physical activity.

Calorie verses calorie

There are two types of calorie designations – Calorie (or kcal) and calorie. Like many other things in science, something can be measured by itself or in multiples of 1,000, such as a gram and a kilogram. The same is true with calories – a Calorie is 1,000 calories. Where the confusion comes in is on nutrition labels. What shows as a calorie is actually 1,000 times that amount or a Calorie or kcal. So if a label shows that cookie you are about to eat has 250 calories, it actually has 250,000 calories.

But how it is measured is really irrelevant, because the same unit of measure used on nutrition labels is the same we use in calorie expenditure; with that measurement equal, it makes it easy to know how many calories you take in versus how many you burn.

Calories are your friends

In the world of weight loss, calories are viewed as a bad thing – something to avoid in order to lose weight. In reality, our bodies need calories to survive; without them, we would die. The key is to manage how many calories you take in versus how many you burn up. When you burn more calories than you eat, you lose weight; burn 3,500 calories more per week than you take in and you lose a pound.

Not all calories are created equal

You would think a standard quantity of something, such as 1 gram would contain the same number of calories. Wrong! While 1 gram of either carbohydrates or protein each contains 4 calories, 1 gram of fat contains over twice that amount – 9 calories. So what you eat has a major effect on how many calories you consume. By eating a gram of fat, you are taking in twice as many calories than if you ate a gram of carbs or protein.

So now you know what a calorie is, how it is measured, and the number of calories in a gram of carbohydrates, protein, and fat, you can use this information in your quest for a healthy lifestyle.

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