Q. Can stress cause weight gain?

A. If your job is stressful, your teenager is threatening to quit school or you are caring for sick parents, it could affect your weight. Several studies have shown a relationship between chronic stress and our weight.

Our prehistoric ancestors feared being attacked by wild animals. When they were in danger, their bodies reacted by flooding the bloodstream with "stress hormones" such as adrenaline and cortisol to improve alertness and strength. This reaction is often called the "fight or flight" response.

Today, we often experience emotional stress rather than physical threats, but our body's reaction is the same.

Adrenaline increases our heart rate and muscle strength. Cortisol sends sugar to our brain and muscles so we can think clearly and run fast.

After a stressful event, adrenaline exits, but cortisol lingers. Cortisol helps your body recover by increasing your appetite to help replace the energy burned while fleeing or fighting. Since you weren't running away from a saber-toothed tiger, but are sitting around stewing about your hectic life, this stress reaction can pack on the pounds.

Your body doesn't know that you didn't fight or flee, so it still responds to stress with the hormonal signal to replenish nutritional stores, making you feel hungry.

People with high cortisol levels often choose fatty, starchy or sugary foods to ease their stress. This extra sugar increases insulin levels. When faced with stress regularly, excess cortisol and insulin cause your body to accumulate belly fat. Too much belly fat increases your risk for heart disease and diabetes.

If you let your hormones rule, you will eat more. Instead, engage in activities that help reverse the stress response. These include yoga, tai chi, meditation or breathing exercises. They produce a relaxation response by slowing down your heart rate and breathing.

Another stress-buster is exercise. It burns calories and helps your brain release "feel good" chemicals. Exercise can also reduce cortisol levels.

For some people, eating in response to stress is a learned habit, rather than a hormonal response. Simply reducing cortisol won't stop you from eating fatty, sugary snacks if they're lying around your house or you're in the habit of munching whenever you're upset.

To keep your blood sugar steady, don't skip meals. Balanced meals and steady blood sugar levels reduce insulin and cortisol levels, ultimately controlling your appetite and weight.

Amy Tousman is a registered dietitian and certified diabetes educator with Nutrition Unlimited in Kailua. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; e-mail islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.