How do you measure how Fat you are?
Bioelectrical impedance analysis (BIA)
There is a range of ways in which to measure body fat levels. These range from the most accurate which would be upon death removing all of your body fat from you and weighing it to using Body Mass Index as the least most accurate. One of the more popular tests coming into the consumer market now is that of bioelectrical impedance analysis.
How does BIA work?
In conventional BIA, the following information is required, the person’s weight, height, age, gender and other physical characteristics such as body type, physical activity level, ethnicity, etc. are entered in a computer. The people then lays down with electrodes are attached to various parts of the body and a small electric signal is circulated.
BIA measures the impedance or resistance to the signal as it travels through the water that is found in muscle and fat. The more muscle a person has, the more water their body can hold. The greater the amount of water in a person's body, the easier it is for the current to pass through it. The more fat, the more resistance to the current. BIA is safe and it does not hurt. In fact, the signal used in body fat monitors cannot be felt at all either by an adult or child.
So the more dehydrated the person is the higher their body fat levels are. The more overhydrated the person is the lower the body fat scores. Therefore BIA operates on an algorithm that provides an estimate of body fat levels based on assumed fluid content.
The accuracy of BIA measurements is also limited by different sources of error such as physical model, cross sectional area, ethnicity, body hydration, age and level of body fat among other variables. Equation for each population is required as they can produce overestimation when manufacturer's equations are used.
The classical measurements hand to foot has shown better correlation against hydrodensitometry than foot-to-foot or hand-to-hand. However there is a lack for an accepted standard of BIA procedures. This is compounded when there is not a good report of the BIA study's methodology; hence the comparability between the results is poor and reduces the reliability of the method.
So if you are using a hand-to-hand model or a foot-to-foot model then your results will be variable and not at all accurate. If you have trained, not eaten the same foods consumed the same liquids and have rested the same amounts then your results will be inaccurate. They will also be inaccurate if you are in an overtrained state as well as if you have neural fatigue.
So while BIA will give you a ballpark estimate of your body fat levels you as a client have to remember that it is a ballpark estimate not a 100% accurate measurement.
