Bioelectrical impedence analysis is the method that Tanita scales utilize to measure body fat. These devices work by measuring the resistance of a small, water-conducted electrical signal that is sent through the body. The more muscle mass an individual has, the more water their body holds and the easier the signal is conducted. If a person has more fat, the signal will face greater resistance and the calculation of body fat percentage will be higher.
Together with bioelectrical impedence analysis, Tanita scales consider an individual's height, weight, age and gender to estimate body composition. Tanita scales look like regular bathroom scales, but electrodes under the scales' metal foot sensors send a gentle electrical signal through the body to measure body fat. Tanita was the first company on the market to introduce body fat scales using this patented technology.