Body composition is a useful tool for measuring health as the BMI does not show the full picture. This is because muscles and bones are denser than fat and since the BMI takes into consideration only height and weight, it sidesteps these differences. In fact, the New York Times ( is publishing stories about the inaccurate uses of BMI.  In other words, if you want to assess your health and fitness, you need to be involved with body composition analysis. In order to do that, you need a device that measures body composition. Some of the most popular body composition tools are devices that use bioelectrical impedance analysis (BIA).

What is it?

Bioelectrical impedance analysis (BIA) is a safe method to measure the body composition in which various variables such as gender, race, height, weight, and age are taken in consideration as well. In other techniques, certain variables such as race are not taken into consideration leading to an inaccurate theoretical metabolic rate and calculations.

What is the difference between the bioelectrical impedance scale vs machine?

There are different types of BIA devices, but each device requires two points of contact. Body fat scales are one of the most popular ways to measure your body fat, mainly because they’re quick and easy to use. Most research shows that body fat scales aren’t accurate at tracking individual changes in body composition over time.

On the other hand, the BIA gives you a fairly accurate representation of your body composition. When the BIA is used regularly it can show you changes in your body fat over time. The actual number may not be perfect, but the BIA machine is the best you can have to track changes in your body composition with diet or exercise. In fact, some studies published in 2015 showed that bioelectrical impedance analysis is an accurate method for estimating body fat in the BIA machine and not for the scales you find in the store.

How does it work?

It works by a painless, weak electrical current. It measures the difference in resistance when the weak electrical current is conducted through fat or lean muscle components of the body. The BIA estimates the whole-body fat content according to the total body water content of your body.

In conclusion, if you are looking for an accurate representation of what your weight consists of, if it is muscle or it is mainly fat, you should consider using a reliable bioelectrical impedance analysis. At Registered Dietitians Services, we are equipped with the latest equipment of the BIA and therefore we invite you to contact us for an appointment.

BIA – Bio-electrical Impedance