By means of the Bioelectrical Impedance Analysis (BIA). This technique is based on the fact that non fat human tissues contain water and therefore are good conductors of electricity. The fat tissues contain less water and conduct less electricity. We send a low energy and high frequency electrical current (50 Khz, 500 microampers) from one contact of the Health Kiosk unit going through the body of the user and we measure the loss of voltage (impedance) when arriving at the other contact. We know that there is a direct relationship between the impedance and the volume of the conductor, so we can estimate the amount of water in the body, of the non fat mass and finally of the body fat. The estimation of the body fat percentage is the result of applying several formulae combining the impedance with the weight and height as well as the indication of age and gender of the user.