Testing the Body Fat Tests

Washington Post reporter Howard Schneider was never a big believer in body fat as a measure of fitness, or, for that matter, of body fat measure as a measure –of anything. In this piece, which includes a less-than-information-packed video, Schneider introduces innocent readers to a technology called bioelectrical impedance, which passes a small current
through conductive foot pads or handheld electrodes (and, in some
cases, both). The current can pass easily through water-rich muscle
fiber, but it bogs down in fat. Based on a measure of impedance (how
much of the current gets through from one electrode to the other), the
machines use mathematical models to estimate the amount of fat that got
in the way en route. Wait, there’s more about other ways to measure body fat, but it’s unclear why, because, as Schneider tells us, it doesn’t work.
Read more in the Washington Post.