The truth about calories and why you shouldn't fear them

Dundalk-based Health and Nutrition Coach Lisa Dunbar gives us the low down

Lisa Dunbar


Lisa Dunbar


The truth about calories and why you shouldn't fear them

Lisa Dunbar is a Dundalk-based health and nutrition coach

This week I want to have a little chat about calories. I’m sure that’s a word you are probably familiar with.

However, I find that when I actually ask people what calories are, they are either not entirely sure, they can’t really explain them, or they quite frankly just believe that calories are evil little things that make you put on weight!

What Are Calories?

So, to clarify, calories are simply a unit of measurement. They measure and tell us the amount of energy that a food gives us.

First and foremost, the main purpose of food is to give us energy to fuel our bodies, the energy we need to be a living, breathing human being.

It’s kind of like putting petrol in your car. Your car wouldn’t work without that fuel, and similarly, our bodies wouldn’t work without the fuel or energy we get from food, i.e. calories.

How Many Calories Do We Need?

We all need or “burn” a certain number of energy or calories every day. People who exercise a lot, or who are generally more physically active, require more calories because they need and use more energy - just like a car that drives to Dublin every day needs and burns more petrol than a car that is just used for scooting around town!

However, it’s important to remember that we don’t just need or use energy or calories for exercise. Our body is like a factory, one that is constantly switched on, and it needs and uses energy from calories all the time to pump blood, to breathe, to think, to digest…even to blink!

We are all different and have very different needs, but a very general guideline that is often used is that women need about 2,000 calories a day and men need about 2,500 calories a day. This is what will “fill your tank”, if you like.

Now, unfortunately, our bodies are not like a petrol tank that simply won’t accept any more fuel once it is full, and it is possible for us to eat more calories than we actually need or will use up.

When this happens, our bodies have to store that extra energy… as fat! This is mainly how we put on weight and the reason why calories are often associated with weight gain. So, to be clear, despite their bad reputation, calories in and of themselves are not to blame for weight gain.

We need calories to live and survive. It is the OVEREATING of calories that causes weight gain - when we eat more calories than our body actually needs.

Not All Calories are the Same

This relationship between calories and weight gain is why I meet a lot of people who are very preoccupied with counting calories, and they decide what foods to eat based on how many calories are in them.

But I want to explain something very important about calories - they are not all created equal! For example, if I take a chocolate bar in one hand and a banana with some nuts in the other, both of these 2 snacks have exactly the same number of calories.

Therefore, they give me the same amount of energy. Someone counting calories and basing what they eat on the number of calories in a food could look at these two snacks and consider them to be equal, usually opting for the chocolate bar because, well, it tastes nicer! However, there is a big difference when you consider the QUALITY of the calories in both snacks.

The banana and nuts, being nutritious whole foods, have the added bonus of being full of vitamins and minerals and good protein and fat, things that will all contribute towards my health. The chocolate bar, on the other hand gives me so-called “empty calories”, just energy, with nothing extra that will contribute towards my health.

Empty calories don’t satisfy your body. They don’t make you feel full and so you end up craving more and therefore overeating.

This is why it is so much easier to overeat and therefore put on weight if your diet is filled with a lot of processed foods such as chocolate, sweets, crisps, biscuits, fizzy drinks, etc.

So, my message is this - you must look beyond the number of calories in a food and think about whether the food is actually good for you! Calories that come from whole foods such as fruits, vegetables, whole grains, nuts, seeds, beans, lean meat, etc are much better quality, will satisfy your body AND maximise your health! 

Lisa is a Nutrition and Health Coach based in Dundalk. Having used diet and lifestyle changes to help recover from physical and mental health challenges, Lisa is now on a mission to motivate others to live a healthier life. See: or follow Lisa at: This article also appears in the print edition of this week's Dundalk Democrat.