It is used in the the health industry and sometimes by doctors (although doctors tend to prefer BMI which is near on useless) to determine whether you are ultimately in a physically healthy state.
But much more importantly one particular percentage is of utmost importance when concerned with losing weight or staying in great shape. If you want to look like the lady on the left then ladies you better get your body fat to around 20% and men around 15%.
The easiest way to measure your body fat percentage is with the use of calipers. You will find these in most health clubs and they are pretty easy to use, although the accuracy of the results depends on the competency of the person taking the measurements.
Most commonly 3 sites or points on the body will be measured, these being:the right bicep, right triceps, right sub scapula and the right suprailliac. This is known as the durham womersley formula.
Other ways to measure include: MRI scans, water weighing and electrical impedance devices.
The first two methods will be out of reach for most of us but electrical impedance devices are becoming readily available and can be found in most gyms.
Electrical impedance devices work by sending tiny impulses through your body and thus measuring your body fat. Now these things are a bit of a gimmick and are very inactuarate. They usually over estimate the percentage and give widely different readings each week in my professional experience.
Ultimately if you regularly weigh yourself and at the same time put a tape around your waist, noting the measurement. As long as the tape measurement is reducing regardless of what the scales may be saying then you’re losing body fat.