NUTRITION HOTLINE: Metabolism Test

Q: How will I know if my metabolism is working properly? Are there medical tests for this?

A: Your metabolism is the sum of your body’s metabolic processes, including digestion and absorption of nutrients, energy expended during activity, and the basic functions to maintain your body (i.e., heart pumping, lungs breathing, etc.). General indicators of your metabolism working at an optimal rate include: adequate energy throughout the day, normal body temperature (especially in your extremities), normal bowel function (i.e., not being constipated), adequate energy during exercise, normal mood, healthy growth of hair, skin and nails, a healthy body composition, and a general sense of well-being.

Metabolic rate can be tested using indirect calorimetry. Until recently this type of test was only available in a hospital or research setting, and it was expensive. Now there is a portable test available called MedGem. You sit still and breathe into a hood for 20 minutes, and the machine calculates how much oxygen your body is using and converts it into calories. The test is available at wellness centers, health clubs, and some nutritionists and physicians offices. If you decide to have the test done, consult with your physician or nutritionist for help in interpreting the results. Also, a recent study found MedGem not to be a reliable test for people who currently have anorexia nervosa.

The best way to optimize your metabolic rate is to not diet or restrict calories, to eat 5–6 times per day, and to exercise regularly. In addition, your thyroid function influences your metabolic rate, so ask your physician how often you should have your thyroid function tested, and find out if anyone in your family has had thyroid disease because the most common types of thyroid disorders tend to run in families.