How to calculate your daily energy needs
Just as no two people are exactly the same, our daily energy needs vary from one individual to the next. The following reference values should help you to determine your daily needs easily and quickly so that you can be confident of ordering the right emergency supply package for your family or friends.
Basic Metabolic Rate (BMR) and Physical Activity Level (PAL)
Your daily energy requirement is made up of your Basic Metabolic Rate (BMR) and your Physical Activity Level (PAL). The Basic Metabolic Rate measures the amount of energy a person uses while resting and lying down for 24 hours. Our bodies need energy to maintain our body temperature and stay alive.
The BMR varies from one person to the next and depends on a variety of factors such as body weight, body size and muscle mass. The larger and heavier a person is, the greater their BMR. A person's gender, age and physical fitness also influence their BMR. The BMR is considerably higher for men than for women, and for young people than older people. Factors such as stress, medication, illness and even the climate also have an influence.
As a rule of thumb, however, we can realistically say that an average BMR is 1 kcal per kilogramme of body weight.
Basic Metabolic Rate
| Age (years) | Body weight(kg) | Basic Metabolic Rate (kcal/Tag) | ||
 |
 |
|
|
|
| 15 to 19 | 67 | 58 | 1820 | 1460 |
| 19 to 25 | 74 | 60 | 1820 | 1390 |
| 25 to 51 | 74 | 59 | 1740 | 1340 |
| 51 to 65 | 72 | 57 | 1580 | 1270 |
| over 65 | 68 | 55 | 1410 | 1170 |
Hardly anyone spends their whole day lying down and resting. People work or play sport.
You will therefore need to add your daily Physical Activity Level to the above BMR figure. This will be a combination of your work and leisure activities.
There are large differences here too, depending on the amount of physical activity that you expend in your job and your free time. If your job mainly involves sitting or standing (office worker, waiting staff) you will use less energy than if you have a more physically demanding job such as a construction worker, mechanic, miner or forestry worker.
The following guidelines will be useful in estimating your daily energy requirements.
A 20-year old man needs approximately 3,000 kcal per day. A 65-year old woman, by contrast, can get by with 1,800 kcal. These guidelines are valid for persons who undertake light activities during the day. If you carry out hard physical work, you should add a further 1,200 kcal, or if your work is particularly strenuous, a further 1,600 kcal per day.
Daily energy requirements guidelines
| Age (years) | |
|
| 15 to 19 | 3100 kcal | 2500 kcal |
| 19 to 25 | 3000 kcal | 2400 kcal |
| 25 to 51 | 2900 kcal | 2300 kcal |
| 51 to 65 | 2500 kcal | 2000 kcal |
| over 65 | 2300 kcal | 1800 kcal |
Stress levels rise in emergency situations and make additional physical demands on us that require extra energy. It is therefore particularly important to ensure that your emergency supplies are able to provide what your body needs.