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Let's talk Calories

Some people embrace them, others fear the very word. But what are they? What do they do for us? And how can we use them?

What is a calorie?

For some they are their best friend, for others their worst enemy but do we know exactly what a calorie is and what they do for us? To put it simply a calorie is a unit for measuring energy. They are found in just about all food and drink locked away in chemical bonds. Once these foods and drinks are consumed by you and me the chemical bonds are broken down and the energy (calories) is released into the body ready to be used. [1]

Once this energy is released into your body there are really 3 things that can happen; you will either burn this energy through bodily functions and exercise, you will store any energy that you do not use as body fat or it will simply exit your body the next time you go to the bathroom, how lovely.

What do they do for us?

So now we understand that calories are in fact energy is becomes pretty clear that they are used to fuel us on a day to day basis. One way they do this is through bodily functions such as digestion for example. Your body needs energy in order to perform and function so even if you spent the entire day in bed you are still technically 'burning calories', this is known as your basal metabolic rate (BMR) which is simply the number of calories your body burns in a state of rest in order to perform the most basic of tasks like digestion and breathing etc.

Another way in which our bodies use calories, which you should all be familiar with, is to fuel us for exercise. We've all finished a tough workout and checked our smart watches to see just how many calories we've burnt. Another way of looking at it is how much energy you've used up during your session. If it wasn't for the calories we consume from food and drink we just simply wouldn't have the energy our body needs to get through these intense workouts.

How can we use them?

So we now know what a calorie is and how our bodies use them, how about how we ourselves can use them to change our body composition and fuel us correctly? Well when it comes to weight gain or fat loss there are 3 things we can do with calories, these are; a calorie surplus (when we consume more calories than we burn, gaining weight), a calorie deficit (when we burn more calories than we consume, losing weight) and a calorie balance (when we eat the same amount of calories as we burn, maintaining weight).

So how do we work out our calories once we've decided whether we want to gain weight, lose weight or maintain weight? This is where our old friend the BMR comes back into play. By working out our BMR we can then work out how many calories we need daily in order to achieve our goals. To work out your BMR, try using the Harrison Benedict Formula. [2]

  • For men: 66.5 + (13.75 x weight in kg) + (5.003 x height in cm) - (6.755 x age in years)

  • For women: 655.1 + (9.563 x weight in kg) + (1.850 x height in cm) - (4.676 x age in years)

Once we know what our BMR is we then need to factor in our lifestyle and how many calories we burn through being active, whether that's from exercise, a physical job or simply walking to and from places. If you do little to no exercise/activity multiply your BMR by 1.2, light exercise/activity a couple of times a week multiply it by 1.375, moderate exercise/activity 3-5 days a week multiply by 1.55 and high exercise/activity 6-7 days a week multiply by 1.725. Once you've finished your maths for the day you will know exactly how many calories you need to be eating every single day to maintain your bodyweight, congratulations.

1 pound of fat is made up of 3500 calories, yeh that's a lot of calories! What does this mean? Well this means that if we wanted to lose weight and we've decided to try out a calorie deficit then in order to lose 1 pound of bodyweight a week we would need to consume 3500 calories less. Seeing as though you worked out your daily calorie needs we can divide 3500 by 7 which equals 500. Meaning per day you would need to eat 500 calories less than your maintenance in order to lose 1 pound of bodyweight per week. This is also the same if you are trying to gain a pound a week by flipping it and consuming 500 calories above your maintenance calories per day.

Well that's just about it for our talk on calories for today. I do hope you have taken something away from this besides a headache from all the mathematics! Be sure to check out my other articles for more on fitness and health and please leave a message if you have any other questions. Likewise follow my social media for even more of me:

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  2. The world's fittest book, Ross Edgley, p.171

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