BIA is a method of measuring impedance by applying alternating low-level electrical currents to a user through electrodes placed on their hands and feet. The impedance (resistance) that the current encounters as it travels through the body is measured. Because different cells contain different levels of water (and therefore yield different impedance), the InBody is able to accurately differentiate between the 4 main components of the human body - minerals, protein, fat, water.
BIA is a non-invasive method and most users experience no sensation at all. It is important to note that body composition results will be affected in the case of pregnancy, breast augmentation, irremovable piercings, metal plates/pins/screws, or where a pacemaker, defibrillator or nerve stimulator are present. It is not advised to scan if you are pregnant or have a pacemaker.