Women's Health

Bathroom Scales Don't Tell The Whole Story

Infrared Light Measuring

Infrared light measuring is an inexpensive way to measure body fat with a soil-analysis-type device that agronomists use, Bryant explains.

Here's what happens: A probe is placed on a body site -- the biceps, for instance -- sending an infrared light ray through both fat and muscle. Your height, weight, sex, age, frame size, and activity level are factored in. The final number is a "rough estimate" of your body fat percentage, says Bryant.

Price: $25 to $50 per test.

The verdict: "It hasn't proven to be terribly accurate," Bryant tells WebMD.

Grade: F. Don't waste your time or money, says McCrory.

Height/Weight Charts

These are the simple height-vs.-weight tables used for years by many insurance companies. But the experts say they just don't work very well, even if they take body frame and sex into account.

Price: None.

The verdict: "These charts have significant limitations," says Bryant. "They really aren't measuring fat-to-lean tissue. They are based on a limited sample of the population and can be misleading."

Grade: F. "These do nothing to help us understand body composition," Kravitz says.