Measuring weight alone is not a completely accurate assessment of health or fitness because it does not distinguish the weight that come from fat and weight that come from lean body mass (bone, muscle, organ, blood and etc.). Everyone needs some body fat, but too much or too little body fat has health risks.

Awareness and monitoring of body fat percentage can be motivational tool for a fitness and weight management program. Additionally, with any chronic degenerative disease, monitoring body fat and lean body mass is critical to evaluation, treatment, and management of the condition. This information is helpful in determining a suitable exercise and nutritional program on an individual basis.

In Asian populations, morbidity and mortality is occurring in people with lower body-mass index or BMI (the weight in kilograms divided by the square of the height in meters) and smaller waist circumferences. Thus Asians tend to accumulate intra-abdominal fat without developing generalized obesity. It is this internal body fat that is often overlooked by other surface testing methods. Realizing this characteristic, a simple and relatively reliable method to measure obesity or intra-abdominal body fat is required.

It is possible to measure body fat by various means, but most of these require sophisticated apparatus and techniques beyond the scope of most consumers. Bio-electrical impedance (BIA) which both Tanita and Omron Body Fat Monitor applied, is an easy to use technique and offer reliability.