But exercise and liquid intake before the test can skew results. It under- or overestimates body fat by only 1 percentage point. An egg-shaped chamber that offers precision without pain. You step in, sit for 20 seconds, and that's it. The chamber measures air displacement, which can be converted to relative fat when weight is factored in, since muscular people are denser.
Preliminary tests show it's as good as immersion.
Read the transcript of our conversation with Eric Schlosser, author of Fast Food Nation . Johns Hopkins Hospital 2. Mayo Clinic 3. Massachusetts General Hospital 4. Cleveland Clinic 5.