Although a living person’s body fat cannot be exactly determined, it can be estimated using a variety of methods, such as:
- Anthropometric methods: physical measurements of the circumferences of parts of the body and thicknesses of skinfolds
- Bioelectrical impedence analysis: electrical conductors are attached to the body and low current is passed through these conductors. The resistance between the conductors provide a measure of body fat
- Underwater weighing: also known as hydrodensitometry, the body is submerged underwater and weighed by a special chair. The body density is then used to calculate your percentage of body fat
- Near Infra-red: infra-red beams are directed at the body, which is either absorbed by fat tissue or reflected by underlying muscular tissue
Body fat analyzers are commercial devices made available to the general public, used to measure body fat. There are a number of reasons why one should monitor body fat
- Too little body fat can cause physiological complications
- Too much body fat can increase the risk of illness and disease
- Extreme loss of body fat in a short period may lead to nutrient deficiency and dehydration
It is also useful to monitor body fat during a weight loss program in order to check whether the diet or exercise is appropriate or adequate for one’s needs.
The alternative is to calculate your body fat based on your height and weight using the Body Mass Index http://www.nhlbisupport.com/bmi/. The amount of body fat you should have depends on whether you are a man or a woman. If you are a woman, you should have higher percentage of body fat than a man.
The American Council on Exercise1 suggests the following classification of body fat:
[table id=63 /]
Anything below the essential fat classification and the body is negatively affected, both physically and physiologically. A normal person should aim to have average levels of body fat.