How to Boost Your Metabolism

Four Factors that Slow Your Metabolism

1. Type 2 diabetes: Unfortunately, diabetes appears to affect the metabolism in ways that are not yet fully understood. While researchers have seen trends, it's an area ripe for more study.

"In some studies, people with type 2 diabetes lost weight more slowly and gained it back more rapidly," says Cathy Nonas, M.S., R.D., a spokesperson for the American Dietetic Association and director of the obesity and diabetes programs at North General Hospital in New York City. "Many different factors affect metabolism, including some blood-glucose-lowering medications, so researchers are taking a closer look to figure out why some people with type 2 diabetes have more trouble losing and maintaining weight," she says.

Normally, metabolic rate increases after a meal because the body burns calories when digesting food. This may not be the case in people with type 2 diabetes. "In measuring metabolism, I've found people with diabetes -- and those with insulin resistance -- do not have the same rise in metabolism after eating," says C. Wayne Callaway, M.D., an endocrinologist in Washington, D.C. "Because their bodies don't process glucose normally, their metabolism doesn't speed up as much after eating."

2. Weight: The relationship between your weight and your metabolism is tricky. People who weigh more burn more calories -- their bodies work harder to move the extra weight. By contrast, if you lose weight, your metabolism slows because your body needs fewer calories to maintain its smaller self. So maintaining a lower body weight means eating less, burning more calories through activity, or a combination of both.

3. Low muscle mass: Muscle burns more calories than fat. But when you lose weight, your body loses both fat and muscle mass, which slows your metabolism because you have less muscle to burn fuel. The best way to preserve muscle is to lose weight slowly, eat a balanced diet that is not too low in calories, and be active. Doing activities that maintain and build muscle (strength training or weight-bearing activities) may help to keep metabolic rate in high gear.

4. Skipping meals and undereating: Skipping a meal can lower your metabolism by 5 percent, enough to gain a pound every 1.5 months. "People who skip breakfast and/or lunch have a lower metabolic rate," Callaway says. "Meal-skipping early in the day causes changes in the balance of a number of compounds called neurotransmitters. For example, the neurotransmitter neuropeptide Y goes up, slowing the metabolism, increasing drowsiness, and boosting cravings for carbohydrates."

The good news is that you, like Janet, can speed up your metabolism if it's running in low gear. Read how on the next page.