We all know that for a woman they have only got a daily allowance of 2,000 calories, compared to men who are allowed 2,500 calories. But ask someone what calories are, and the majority wouldn't be able to give you a complete answer.

All they know is that too many calories can contribute to weight gain.

So what are calories? Calories are essentially units of energy. Energy which is used to raise your body temperature. Take this example. One calorie equals the same amount of energy that is needed to raise the temperature of 1 kilogram of water by 1 degree Celsius.

We know, what has this got to do with food, but calories are our way of measuring the energy content of the foods we eat.

Another metrical tool you need to know when you are losing weight, which you won’t traditionally find on a food label, is joules. These measure food energy too, but work on a higher setting. In this case, 1 calorie equals 4,184 joules (with such high figures it is easy to see why companies opt for calories).

Even when you measure it in kilojoules, one kilojoule is still 1,000 joules.
With us so far? Well here is the next secret. When it comes to losing weight, the number of calories you can have will depend on your existing weight.

Take for example this scenario. You have got 2 people who want to lose weight at a rate of 2lbs a week, but one of them is 2 stone heavier than the other.

In this case, the person who is heavier will be able to consume more calories whist losing weight at the same rate as their friend.

You see, because they are carrying extra weight, they need more energy to move it and keep their weight loss steady. Cut your calories down too low and you will not have the energy to keep your body functioning.

Saying this, once the lbs begin to drop off the heavier person of this scenario would have to adapt and lower their calorie allowance to cope with their new weight.

So as you can see, calories play an important part on your path to weight loss. Take this following piece of information for example. To lose just 1lb, you need to burn 3,500 calories – more than your daily allowance.

Now although this looks as though you need to starve yourself in order to lose weight, you don't. We recommend that by cutting your calorie consumption by 250-500 calories a day, you can effectively lose weight at a rate that will enable you to then keep it off.

PLEASE NOTE: you shouldn't cut your calories to below 1,200 a day as this can lead to increased health risks.

The next question is: how can you tell how many calories there are in food? A topic we shall discuss in our next article.