Find Your Metabolic Rate

Your resting metabolic rate (RMR) -- the amount of calories you burn before adding in any activity -- accounts for roughly 70 percent of your daily calorie burn. Knowing this number should help you estimate just how much you need to eat and exercise every day. But until recently, finding your precise RMR could be done only in a laboratory setting. Enter personal RMR monitoring devices such as the BodyGem, a small tool that measures oxygen output from the breath. It is routinely used at high-end health clubs. But at about $50 for a BodyGem test, we wondered if the investment was truly worth it.

"While this data may be helpful to someone on a strict calorie-controlled diet, it has its drawbacks," says Reed Humphrey, PhD, a professor of physical therapy at Idaho State University. "If you log in a low number, you might be tempted to cut your calories too far, which can harm both health and metabolism," he says. Instead, concentrate on a balanced diet and regular workouts. "These are the things to invest in, since they have an impact on what you see in the mirror," he says.