Back to Basics
What is a Calorie?
I’ve decided to start a series called “Back to Basics” where we’ll tackle some important, fundamental topics in the world of health and nutrition, but break them down so they are really easy to understand. The topics we’ll cover might seem simple, but I think that the meaning behind them can get lost in the shuffle and we forget the important concepts they offer.
So, to start the series, I want to talk about calories. We all talk about calories, know we need a certain amount, know certain foods have more than others and that we burn them when we exercise, but do we really understand what all of that means? Maybe not. Let’s take it back to the basics.
What is a calorie?
A calorie is a measure of energy. One calorie is equal to the energy it takes to raise 1 gram of water 1 degree Celsius. So basically, calories are a measure of how hard your body will have to work to burn off the food you put in. Your body must generate a certain number of calories to burn off different foods. Foods get their calorie content based on how much work your body must do to burn them off.
Calories are the energy source that your body uses to fuel everything that it does- breath, movement, digestion, exercise, and everything in between. Every action uses up a different number of calories – the more demanding the action, the more calories used.
How many do I need in a day?
The number of calories you need in a day is based first on your Basal Metabolic Rate (BMR)- that’s the number of calories your body uses just to stay alive and be at rest. Add to that the caloric cost of doing things like eating, digesting , moving and exercising, and you can find out the number of calories you need in a day. That number is different for everyone and there are many factors that go into how quickly you, individually, burn calories.
The source of calories matters.
We’ll use the analogy of a fire - calories are like the fuel you put on the fire to keep it burning. If you put a big log on the fire, it will take a while for it to burn and it will sustain the flame for a long time. If you put a small piece of kindling on the fire, it will burn up and disappear quickly. It’s the same with calories. If you eat a big, calorie dense meal, it will take your body a long time to burn it off and you’ll stay full for a long time. If you eat a tiny snack, you’ll burn it up quickly and be hungry very soon after. If you don’t put any fuel on your fire, it will go out.
We consume calories from 4 different sources and each one provides unique fuel for our bodies. Let’s break the food we eat down into the 4 basic categories.
- Carbohydrates: 4 calories per gram
- Eat 1 gram of food made up of carbohydrates, your body will need to generate 4 calories of energy to burn it off.
- This is our quick burning fuel- or newspaper on a fire. It gives you a big flame right away, but burns up quickly and then goes out.
- Protein: 4 calories per gram
- Eat 1 gram of food that is made up of protein, your body will need to generate 4 calories of energy to burn it off.
- This is a longer burning fuel than carbohydrates – or sticks on a fire. You’ll get a more consistent flame that lasts a bit longer.
- Fat: 9 calories per gram
- Eat 1 gram of food made up of fat, your body will need to generate 9 calories of energy to burn it off.
- These are the big logs on your fire. You will get a good-sized flame that lasts the longest.
- Alcohol: 7 calories per gram
- We all know what happens when you light alcohol on fire. Everything goes crazy and out of control. That’s pretty much what happens in your body when you consume alcohol. We’ll save this one for its own post.
Not only does the source matter, but the quality of that source matters as well. If you think of calories as the fuel for your body, you’re going to want to put the best fuel possible into your system to make it run like a well-oiled machine. If you put poor quality fuel into your body, it will result in poor quality performance and negative side effects.
The number of calories matters
Although it is not as easy as calories in-calories out to maintain a healthy weight, the number of calories you consume does matter. Generally, weight loss occurs through a caloric deficit. When you burn more calories than you consume, your body turns to its fat stores as fuel to generate the energy needed to keep up with demands.
On the flip side. No matter what the source of calories, if you’re consuming way more than you can use and you are not generating the energy to burn them off, they go into storage for later. Your body stores excess calories as fat, assuming it will use them later. If you never use them later, you continue to accumulate fat, gain weight, increase your risk of developing disease and start to mess with your metabolism.
Calories are the fuel our bodies use to live and move, the number you need is based on a variety of factors, and the source, quality, and number consumed matter.
That’s the basics on calories. Next week, we’ll dive into your metabolism- what it is, how it is affected by being overweight, and how you can jumpstart it back into action.