Probably the most accurate body fat-measuring method, dual-energy x-ray absorptiometry uses a body scanner and two low-dose x-rays to read bone and soft-tissue mass. The whole painless procedure takes about 4 to 6 minutes and costs $100 to $250. It is performed at major hospitals, requires a doctor's prescription, and is covered by insurance only when it's prescribed for measuring bone density. If you're concerned about your weight or body fat, ask your doctor whether this procedure is right for you.
Calipers
You're probably familiar with the "pinch" test, which uses calipers to measure the skin-fold thickness in several areas of your body. The idea is that the thickness of the fat under the skin reflects your total body fat. The measurements are then plugged into an equation to determine your body fat percentage. The accuracy depends on the equation used (there are hundreds). One of the best is something called the Durnin and Womersley anthropometric equation, says Jack Wang, codirector of the body-composition unit at St. Luke's-Roosevelt Hospital in New York City. But getting good results also depends on the skill of the person wielding the calipers. You can get tested at most health clubs and universities for little or no cost.
Bio-electrical Impedance
In terms of accuracy, this method is about equivalent to the pinch test, if it's done properly. You've probably seen these scales, which promise to measure your body composition when you stand on them, at places like Bed Bath & Beyond. They are supposed to determine how much fat you have by sending mild electrical currents through your body — the fatter you are, the slower the currents travel. But the foot scale measures only the composition of your lower body. You need to use a handheld version, too, to get accurate results (they come either separately or together in one unit). If you're interested in having your fat measured this way, talk to your doctor.
No comments:
Post a Comment