Our bodies need energy all the time – even when we sleep. In addition, there is the energy for everyday movements and sporting activities. Find out in the article how the value of the recommended energy intake, expressed in kilocalories, is composed.
The basal metabolism – essential for survival
Everyone uses energy (expressed in kilocalories) when they exercise. But even in a state of complete rest, the body needs energy to ensure life-sustaining bodily functions, such as breathing or maintaining body temperature and heartbeat. The amount of this so-called basal metabolic rate varies and depends on
- Age and
- Muscle or. Fat percentage.
Muscle generally consumes more calories than fat tissue at rest. Since men usually have a higher percentage of muscles than women, the basal metabolic rate of men is higher. Muscle mass decreases with age, therefore the basal metabolic rate or. the energy consumption at rest (s. Table). Children, on the other hand, are growing and therefore need more energy. This also applies to pregnant and breastfeeding women due to their special metabolic situation.
The work metabolic rate – activity-dependent
Any physical activity increases energy expenditure. And this does not only mean sport. Standing alone costs the body more energy than lying down. Therefore, salesmen, for example, have a higher calorie consumption than employees who work mainly in a sedentary position. That of a construction worker is even 50% higher than that of an office worker. As a measure of physical activity, scientists use the so-called PAL value ("Physical Acitivity Level"). It is the ratio of total energy consumption to resting energy consumption in a day. It varies depending on the occupation and leisure activity:
- PAL 1.2-1.3: frail, immobile people who are exclusively sitting or lying down
- PAL 1,4-1,5People who are mainly sedentary, such as office workers, and do little or no strenuous activity in their free time
- PAL 1.6-1.7: people who sit and occasionally walk and stand, like students, with little or no strenuous leisure activity
- PAL 1,8-1,9: salesmen, craftsmen or waiters who mainly stand or walk
- PAL 2,0-2,4: people with physically demanding jobs, such as construction workers and farmers, or people who are very active in their free time, such as competitive athletes.
The PAL value varies greatly from person to person, and for many people it averages between 1.35 and 1.6 in everyday life. It usually decreases with age.
The recommended daily energy intake
And how many kilocalories should be consumed daily?? The recommended daily energy intake is calculated by multiplying the individual PAL value by the resting energy metabolic rate. Women aged 25 to 51 with a PAL of 1.4, for example, are recommended to consume about 1800 kilocalories of energy per day. For men aged 51 to 65, a PAL of 1.6 means 2500 kilocalories a day.
A balance is what counts
However, this value only gives an orientation. This is because everyone is different in terms of body composition and also has different levels of physical activity. Activity can also vary considerably over a period of time if life circumstances change, for example if you change jobs or are unable to exercise for a while due to injury. Finally, the energy balance plays an important role. Ideal is a balance between calories taken in and calories consumed.