What is a Calorie?

There are 2 types of calorie a small calorie (kcal) and a big calorie (cal) both are a unit of heat energy. The word calorie is derived from the French word 'calor' which means heat.

A kcal is the total amount of energy required to increase the temperature of 1 gram of water by 1 degree celcius.

A cal is the total amount of energy required to increase the temperature of 1kg of water by 1 degree celcius.

Kcals are what are generally found on food labels as a cal (big calorie) is 1000 kcals so the food type inside the packaging would have to be incredibly energy dense in order for it to be illustrated in cals (big calories). Calories are in everything we eat with the exception of water and fundamentally have the ability to make us either fatter or thinner dependent on your energy prescription. Although quite general and dependable on some other factors the following can be used as a guide to nutrient calorie breakdowns:

• Fat – 9 kcals/g
• Alcohol – 7 kcals/g
• Protein – 5 kcals/g
• Carbohydrates – 4 kcals/g

Carbohydrates are not only the least energy abundant nutrient but are also the human bodies number 1 energy source.