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Energy needs

 

 

 

 

 

 

 

 

 

 

 

 

 

Energy needs

Everyone has individual energy needs, as energy consumption depends on a variety of factors, such as age, gender, health and weight. The energy requirement shows you how much energy you consume during the day and can therefore help you to plan your food intake, for example if you want to gain or lose weight.

If you want to determine your energy needs, you need to determine your basal metabolic rate and assess your activity level. The physical activity of different occupational groups is represented by the PAL (Physical Activity Level) value. To find out what activity level corresponds to your lifestyle, see the PAL table below. Your basal metabolic rate per day depends on age, gender and weight. In the table below you can see how to calculate it.

Once you have calculated your basal metabolic rate and determined your PAL, multiply the two kcal values together to know your daily energy needs.

Basal metabolic rate and PAL value

You can use the following table to calculate your basal metabolic rate (see Biesalski, Grimm & Nowitzki-Grimm, 2020, p. 39):

 AgeFormula for predicting the basal metabolic rate
Women10 - 18 yearsGU = 0,056 * body weight (in kg) + 2,898
 19 - 30 yearsGU = 0,062 * body weight (in kg) + 2,036
 31 - 60 yearsGU = 0,034 * body weight (in kg) + 3,538
 over 60 yearsGU = 0,038 * body weight (in kg) + 2,755
   
Men10 - 18 yearsGU = 0,074 * body weight (in kg) + 2,754
 19 - 30 yearsGU = 0,063 * body weight (in kg) + 2,896
 31 - 60 yearsGU = 0,048 * body weight (in kg) + 3,653
 over 60 yearsGU = 0,049 * body weight (in kg) + 2,459

 

The basal metabolic rate is given here in MJ/day. To get your metabolic rate in kcal/day, simply multiply the value by 239.

After you have calculated your basal metabolic rate and determined your PAL value, you can now calculate your energy needs by multiplying the two values together.  Make sure you multiply your basal metabolic rate by 239 to get a value in kcal.

Example:

Anna is 23 years old, weighs 60 kg and studies biology. She therefore sits at her desk a lot, but is also out and about a lot, goes for walks and occasionally meets up with friends to do sports. She thus has a PAL value of 1.7, so her basal metabolic rate is 0.062 x 60 + 2.036 = 5.756 MJ/day. To get to the calories per day, the value must be multiplied by 239. This gives a basal metabolic rate of 1376 kcal/ day. As a student, she has a PAL value of 1.7, so Anna has a total energy expenditure of 1376 x 1.6 = 2202 kcal/ day.

Biesalski, H., Grimm, P. & Nowitzki-Grimm, S. (2020). Taschenatlas Ernährung. 8. Auflage. Stuttgart: Georg Thieme Verlag.