In actual fact, you will be looking at calorific values that are in ‘kilocalories’. In other words, each unit will represent 1,000 calories at a time. The reason for this is that just one calorie’s worth of energy is a very small unit indeed. One calorie is all that is needed to heat 1 gram of water by 1 degree Celsius, in terms of heat energy.
So, when you are reading nutrition labels, remember that these statistics are presented in kilocalories (or Kcal for short). This is rather a confusing fact, but it does help consumers to understand the number of calories they are consuming far more easily.
As a rule of thumb, there are average calorific values that can be apportioned to each kind of macronutrient. For every one gram of food these are as follows:
- Protein contains 4 kcal;
- Carbohydrates contain 4 kcal;
- Fats contain the most at 9 kcal.
When you are reading the nutrition label, the presented statistics should be pretty much in line with these average figures. So, as an example, if a serving of breakfast cereal (at 30g) without the milk contains the following macronutrient makeup, you should be able to work out the calorific value of this food:
30g of breakfast cereal
- Protein: 3g
- Carbohydrates: 25.5g
- Fat: 0.5g
So with the protein you take 3 (g) and times this by 4= 12 kcal
For carbohydrates take the 25.5 (g) and multiply by 4= 102 kcal
Lastly, with the fat; take 0.5 (g) and multiply by 9= 5 (4.5) kcal.
Your total would be 12 + 102 + 5= 119 kcal within your portion of breakfast cereal.
You may have noticed that the three weights above do not equate to 30g (rather 29g), this is because the breakfast cereal also contains other nutrients (called micronutrients (e.g. vitamins and minerals etc)) and when working out calorific values, these are usually too insignificant to worry about. If you are, then you can always multiply the remaining weight by 4 kcal per gram.
No doubt you never thought it would be as simple as that to work out the calorific values of your foods? When you next look at the nutrition chart on your selected item of food, see if the figures coincide with this guide - they should be very close for you.
So by placing an average calorie content on certain types of foods, we can immediately recognise the fact that fat rich foods are going to contain a lot more calories. In fact, more than twice the values for proteins and carbohydrates. It is therefore imperative, especially when looking to lose weight, for you to watch out for types of foods that contain too much fat.
Each individual has a set Estimated Average Requirement (EAR) for calories in every 24 hour period. But it must be stressed that this is exactly that - an average. If you are leading a much more active lifestyle, it will be necessary for you to increase your EAR accordingly. Conversely, if you lead a more sedate life, the chances are that you will not need as many calories per day.
These averages will vary between males and females and in accordance with your age. They start at around 545 kcal for males and 515 kcal for female babies of up to the age of 3 months. They will then continue to rise to a peak EAR for 15 to 18 year olds, where the EAR for males is 2755 kcal and 2110 kcal.
After this period of an individual’s life (namely puberty), where so much energy is being used to effect the relevant changes in the body, the EAR’s will start to gradually decrease as the individual gets older. Falling to an average EAR of 2100 kcal for men and 1810 kcal for women for 75 year olds plus.
You should bear in mind that these values may vary from country to country and that there are other crucial factors that will dictate that higher calorific consumptions are required. Pregnancy and lactation are two excellent examples for you here.
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