I am suspicious of any device which asks your age to measure your body fat.
Seems to me, when this occurs, a sweeping conclusion is on its way!
We had one of these at my place of employment. When I entered my stats, it stated that I had 12% body fat. When I replaced my real age (47 at the time) with a false age of 30, it said my body fat was 9%.
On further examination, I entered an age of 55 and got a body fat reading of 15.7%. It seems that you are penalized for being older regardless of your true body fat.
About a month later, wanting to get an accurate reading, I was measured by our college’s wrestling coach with a set of calipers. I was the exact same weight, and training the same. The coach measured me at 8.9%.
It seems that when I entered the age of 30 into the electronic body fat analyzer I got the most accurate reading (9%). Anything below that was inaccurate because the reading was to low. above that figure and the reading was to high.
When they come up with an electronic body fat analyzer where you do not have to enter your age, you will know that they have taken a step in the right direction.