The energy requirement or calorie requirement is made up of the basal metabolic rate and the turnover and varies from person to person. We have an increased energy requirement in case of stress, fever and hyperthyroidism, as well as women during pregnancy and breastfeeding - in old age and in mental disorders, the need is reduced. Another climatic influence also plays a role. Thus, in high cold or heat, the calorie requirement is also increased.
The basal metabolic rate is the daily amount of energy necessary to control all bodily functions (breathing, heartbeat, muscular activity, etc.) in Quiet over a period of 24 hours. It is about 60 to 70% of the total calorie requirement. During sleep, it drops by 10%.
The basal metabolic rate depends on age, height, gender and weight. The higher the body weight, the higher the basal metabolic rate. However, fat tissue uses much less energy than, for example, muscles. So, if you do sports, you have the advantage, because the larger the percentage of muscle mass, the higher the basal metabolic rate.
For the calculation of the basal metabolic rate - as the exact determination of fat and muscle mass is difficult - mostly the body weight is used.
The turnover is mainly determined by the physical activity at work and leisure time. The calorie consumption through physical activity is about 20 to 30% of total calorie consumption.
The power turnover is today often determined using the so-called PAL values - Physical Acitvity Level. The PAL depends on the type and duration of professional or sports activities:
|Very low||Only sitting or lying down, for instance when ill or in old age.||1,2|
|Light||Only sitting with less or no physical exertion, for example screen work, without sporty compensation.||1,4-1,5|
|normal||Seated activities, going or standing in between, for example motorists.||1,6-1,7|
|Moderate||Predominantly walking and standing activities, for example salesmen, waiters, craftsmen, housewives.||1,8-1,9|
|Heavy||Physically demanding activities, such as construction workers, competitive athletes, farmers.||2,0-2,4|
In order to maintain the body weight, food must be supplied with the individually required amount of energy. If this value is exceeded in the longer term, it can be expected that the body will accumulate the excess energy in the form of flab.
Calculation of the energy requirement
To calculate your calorie requirement, there is an interactive energy demand calculator from the University of Hohenheim.