Special Device Looks At Resting Metabolic Rate For Weight Loss

For the first time, Karen Fox is taking steps to lose weight. She blames the extra pounds for her diabetes, knee problems and even a recent bout with breast cancer.

"It was time to stop it. [It was] past time to stop it," Fox said.

Fox is turning to more than just exercise and diet. She is using her resting metabolic rate (RMR) to determine just how many calories she can eat and still lose weight. Your RMR is the amount of calories your body burns at rest.

"Throughout the day, you'll burn X amount of calories. Your resting metabolic rate is about 75 percent of those total calories," said Chris Hennie-Roed, a physical therapist at Healthsouth.

Hennie-Roed uses a new device called MedGem to determine that magic number for weight loss. Fox breathes into the machine for about 10 minutes, the amount of time it takes for the device to get a good stabilized breathing rate.

Until now, Fox said she used an equation based on height and weight. However, that calculation could be off by as much as 900 calories.

"If you're off by as little as just 100 calories a day, that will add up to 10 pounds a year," Hennie-Roed said.

Fox is also keeping a computer food diary to track what she eats. She said she has already lost several pounds, but she wants to shed 90 pounds.

"I'll be happy when I lose that," she said.

Since RMR decreases as you lose weight, experts recommend getting retested every time you lose five percent of your body weight. The test costs around $75.