To properly fulfill its various missions, our body must receive energy. Provided by our diet, this fuel allows it to accomplish its cognitive and physical functions. Even if in everyday language we more often hear the term “calories” to refer to energy needs, it is in reality kilocalories (1 kilocalorie = 1,000 calories).
What is daily calorie expenditure?
Daily calorie expenditure is characterized by the energy that the body needs to carry out our activities All day long. Everyone has a different daily energy expenditure. “On average, it is estimated that a woman needs approximately 2,100 kilocalories per day And that a man needs 2,600 kilocalories per day. This is very approximate, because everything depends on the person’s age, gender, physical activity, psychological state, eating habits and metabolism.” explains Marine Besse, dietitian-nutritionist.
How to calculate daily calorie needs?
Different calculations make it possible to obtain a rough estimate of daily needs in calories. There is, for example, the equation of Black et al, which allows, firstly, to evaluate one’s basic metabolism, in other words the quantity of energy that the body needs when it is at rest. Please note, the coefficient is different for men and women:
- in a woman, her basic metabolism = 0.963 x P in kilocalories (index 0.48) x T in m (index 0.50) x A -0.13
- in a man, his basic metabolism = 1.083 x P in kilocalories (index 0.48) x T in m (index 0.50) x A -0.13
Take the example of a 30-year-old woman weighing 56 kilograms and measuring 1.65 meters. The calculation to estimate your basic metabolism corresponds to: 0.963 x 56 (index 0.48) x 1.65 (index 0.50) x 30 -0.13 = 5.48. We thus obtain an estimate of your resting energy expenditure in kilojoules/day.
To obtain the daily requirement in kilocalories, simply calculate the result obtained, or 5.48, and multiply it by 1000/4.1855. The calculation is as follows: 5.48 X 1000/4.1855 = 1309 kilocalories/day.
How to obtain our total energy expenditure?
In order to know the exact energy expenditure, it is then necessary to multiply basic metabolism (i.e. 1309 kilocalories / day in the previous calculation) with physical activity level (PAL) of the person.
“The NAP is on average 2.5 for an individual, who is on his feet regularly during the day, has a non-sedentary job and is physically active. The more physical activity increases, the more this NAP increases, up to 5 and more among high-level athletes or workers with intense professional activity. On the other hand, it is around 1.5 percent. sedentary people“, indicates Marine Besse.
Total energy expenditure is therefore equal to basal metabolism x NAP.
With this value, we can then measure the distribution of this energy according to the three macronutrients provided by our diet:
- Proteins between 10 and 20 percent of total energy;
- Lipids between 35 and 40 percent;
- Carbohydrates between 40 and 55 percent.
Online, there are multiple calculators allowing you to obtain your daily kilocalorie needs. As Marine Besse reminds us, we must not only focus on these results if we wish to maintain a healthy weight. “These are elements that vary so much between two individuals. Furthermore, the nutritional aspect is missing. To be healthy, it is essential to eat as varied a diet as possible with colorful dishes rich in nutrients and antioxidants. Daily physical activity is also recommended. Make short trips on foot, take the stairs instead of the elevator… The goal is to exercise as much as you eat to maintain a stable weight”she concludes.
Thanks to Marine Besse, dietician-nutritionist