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Kcal per day formula

What is a kcal?

Published 2 years ago at 29 Aug 2019 by Alexandra Soare

During the first industrial revolution two things happened:


  1. With the invention of heat engines, physicians had to find a way to define heat.
  2. It was a weird time to be alive.


So they invented the CALORIE (from Latin calor = heat) and decided that :

 1 cal is the amount of energy required to warm one gram of air-free water from 14.5 to 15.5 °C at standard atmospheric pressure.


Why am I saying this story? For no particular reason, just find it interesting they decided to warm up 1 gram of water from 14,5 to 15,5°C and call it 1 calorie and thought you might find it interesting too.

But apart from heating engines, the calorie has been used since then in nutritional science to describe the energy (in form of heat) that food can release in the body. This is the reason why the phrase “you are burning calories” is so popular. Because that is literally what is happening in our bodies.


Why it is good to find out how many calories per day should you consume?


According to the study linked below from 2013, just by being aware of the amount of kcal the participants were consuming, they could reduce the consumption in an easier way. 


Which is the best formula to find out your calorie intake? 

There are different formulas out there, so pick up the right one! 

The ones currently used by the WHO (World Health Organization) were invented in the past century. They have some limitations as they tend to overestimate your resting energy expenditure when is low and underestimate the resting energy expenditure when it is high. 

 That´s why, thanks to the new research from 2004, this new formula better describes our basal metabolism:


For women:

((0,047 *[KG]+-0,01452*[YEARS] + 3,21)*239)*PAL


For men:

((0,047 *[KG]+1,009*1-0,01452*[YEARS] +



What is PAL?


PAL stands short for Physical Activity Level. When finding out your recommended calorie intake, you should take also the physical activity into consideration.

 According to the FAO:


PAL value

Sedentary or light activity lifestyle

Active or moderately active lifestyle


Vigorous or vigorously active lifestyle


How to find out where you belong?

Sedentary or light activity lifestyles:

  • if you use mostly your car or motorcycle
  • if your job does not require you to walk long distances.
  • if you don't exercise or participate in sports regularly
  • if you have an office job.



Active or moderately active lifestyles:

  • if your job requires you to moderately move like: being a student, part-time waiter,
  • if you spend at least one hour a day jogging, cycling or other sports activities.



Vigorous or vigorously active lifestyles:

  • if you have a job very demanding physically like agricultural labor, dancer,  nurse, waiter.
  • if in your free time you practice sport on an almost professional level.


How to calculate caloric intake




Read more:

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