What Is a Calorie?

What a calorie is and why they are different.

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 verses 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 verses 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 a 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 will use this information in your quest for a healthy lifestyle.

Why All Calories Are Not Created Equal

You have probably heard the old adage “A calorie is a calorie”. It suggests a calorie is the same regardless where it comes from. The problem is the adage is all wrong! While all calories are the same in regard to the energy content in each, how the body process each type varies. Here are five things to keep in mind when trying to manage your weight.

Energy required to process calories

We all know that our body burns calories to digest, absorb and metabolize food into energy. But what you may not know is that your body uses higher number of calories to process protein than it does for carbohydrates and still a lower number for fat. This suggests your body stores less calories on a high protein diet than one high in carbohydrates or fat due to the extra calories it takes to process protein.

Effect of calorie restriction

The above 3,500 calorie per week deficit to lose a pound will work for a while. But soon you will find you are losing less weight each week even though you are consuming the same number of calories. Why? It is called metabolic adaptation or “starvation mode”. Your body recognizes the calorie reduction and it begins to work more efficiently – doing more with less. In doing so, it in effect increases the value of each calorie. Your body gets more mileage out of each calorie now than it did before.

Protein is your friend

Protein satisfies you better over a longer period of time. If you don’t feel hungry, you are less likely to eat. This further supports the theory that not all calories are the same. If you eat junk food loaded with saturated fat and simple carbohydrates, you’ll not only end up consuming more calories at the time, but you’ll be looking for something to eat sooner than if you would have eaten turkey breast, chicken breast, tuna or lean beef.

Fiber slows absorption

Even though most fiber comes from carbohydrates, it is not absorbed by the body, so in effect; it keeps you fuller longer and reduces your desire to eat. So calories in a high-fiber diet are more satisfying than ones in a low calorie diet – yet another way, calories are different, even within the same macro-nutrient.

Timing your meals

A study published by the American Journal of Clinical Nutrition found that the thermal effect of food – the energy used in the digestion and absorption of food – is higher in the morning that during other times of the day. As a matter of fact 16% higher; it proves we burn more calories in the morning. Food calories consumed right after waking from a sleep are more likely to be used and not stored.

Even though these five things do have a minimal effect on weight management in the short term, just understanding how your body processes different types of calories can make a difference over the long haul. As the saying goes “Every little bit helps.”