The only really accurate way to measure body fat is in a tub of water, where you're hooked up to machines that check the lean mass percentage. This is a very expensive test, and is rarely performed for people who are not professional. The scales you relate can give you a general idea, but I wouldn't hold much stock in the actual figures. Get the idea, and try to become healthier, keep to a regular diet and workout schedule. Check for the trend of the numbers rather than the actual figures.
