Weight scales for women, or body-fat scales, are often inaccurate, says BerkeleyWellness.com. Results depend on a number of factors, such as how hydrated the body is, how recently a meal was consumed, or how long ago exercise was taken, so does highly-calloused or even dirty soles .
The quality of the scales themselves is another factor. Inexpensive body fat scales are likely to perform less well than more expensive models.
Body fat scales calculate the amount of fat in the body by sending a weak, imperceptible electrical pulse from sensors on the scale up one leg, across the pelvis and down the other leg. Because fat contains less water than muscle, the greater the resistance, the higher the level of body fat.