Fat is a special tissue and is complex existence in the body, including subcutaneous fat, visceral fat and the like, and is widely present in various parts of the body. Currently, there are several popular methods for measurement of fat percentage in the world, including DEXA, BIA, a method for weighing in water, and so on. Different measurement methods have their own unique algorithms and have different results. So far, the method for weighing in water and DEXA (dual energy X-ray absorption method) are called "gold standards", however, repeat test results with these gold standards have also shown present error. Therefore, the biggest problem of body composition analysis is: no instrument can give an absolutely correct answer. Household body fat scale manufacturers mostly use BIA measurement method, but results are also different due to different algorithms; therefore, it is not suggested that users be entangled indifference of absolute values measured by different instruments and equipment but should pay more attention to relative change value measured by the same equipment for a long-term
Therefore, we suggest that a user tries to use the same assessment system for long-term monitoring and control and measurement of fat percentage; long-term change value can be assessed to obtain a person's health status change trend, and mastery of health trend is the most important, thus, we believe that relative value of change is more meaningful than absolute value of a single measurement.