What is Body Impedance Analysis?

January 28, 2009

I have relied too much on weighing scales to tell me that I am on the healthier side of the population. But I have recently discovered that not being overweight doesn’t always mean that you are healthy. Did I see your jaw drop down? Mine did too… Body weight actually includes the mass of both the body fat as well as the muscle. An excess of body fat should set the alarm bells ringing.

Body Impedance Analysis or Bioelectical Impedance Analysis (BIA) is a reliable method to estimate body composition. It is also a non-invasive method - great news for people like me, who are scared to death even at the mention of a needle! Traditionally, a patient’s height, weight, age, gender, and other aspects like body type, physical activity level, ethnicity etc. were entered in a computer. The patient was then made to lie down and electrodes were attached to different parts of the body and an electric signal is passed through.

The body impedance assessment measures the impedance or resistance to this electrical signal as it travels through the water in the body muscle and fat. The higher the water content in the body, the easier it will be for the signal to pass through, whereas fat resists the flow of the current. This resistance is used to calculate the total body water, which is used to calculate the fat-free body mass, and finally, the body fat.

Tanita has patented a simple one-step process for body composition measurement, which is quick, reliable, precise, and easy. It has included the Body Impedance Analysis technology in a bathroom scale. A low, safe signal is sent through the body by means of the electrodes in the foot sensor pads. Rest assured that this signal is completely safe and doesn’t hurt at all. I am told that you will not even feel it pass through your body. All you need to do is enter your age, gender, and height, and step on the scale to measure your body fat along with the weight.