How to calculate how many calories you should eat when you are fasting + Intermittent fasting calculator
The recommended 500 kcal for women and 600 kcal for men is just an average on how much you should eat. By following my two step guide you will be able to calculate your exact number of calories you should be eating.
Step 1
To calculate your exact calories use the formula below:
For men : 10 × weight in kg + 6.25 × height in cm – 5 × age + 5
For women : 10 × weight in kg + 6.25 × height in cm – 5 × age – 161
The value we obtained is BMR , in English ” basal metabolic rate “. It is the calories your body burns if you would just lie in bed and laze around all day.
An example from my man:
10 x 75 kg + 6,25 x 185 – 5 x 25 + 5 =
750 + 1156 – 130 = 1776 kcal
Step 2
The next step for you is to figure out AMR / TDEE , active metabolic rate / total daily energy expenditure. It is an approximate value for the number of calories you burn, taking into account how active you are. Simplified: If you exercise a lot you get a higher value and if you exercise nothing or a little , you get a lower value.
You get to appreciate how active you are in the following table:
Sedentary / no exercise = 1.2
A little exercise 1-3 times / week = 1,375
Moderate exercise 3-5 times / week = 1.55
Very active 6-7 times / week = 1,725
Hard exercise several times per day = 1.9
When estimate how active you are, you simply take your BMR value and multiply it by the number that best fits how active you are. Here is an example from my man:
TDEE = 1776 ( BMR) * 1.55 ( moderate exercise) = 2753 kcal should he eat ie . 253 kcal more than the recommended for a man / day.
What does this have to do with 5:2 diet then?
On the fasting day, you should eat about 25% of your total AMR / TDEE value. If we take my partner for example, he should eat 2753 calories * 0.25 = 688 kcal . In other words he needs to eat 88 calories more on the fasting days than the 600 calories recommended.
Now maybe you can finally feel that it is more OK for you to eat more or less than 500 kcal by using our intermittent fasting calculator. Comment below if you have any questions about the calculation 🙂
