Can stress make me fat?

If you’ve ever noticed that the numbers on the scale seem to rise along with your stress levels, you might not be imagining things. Stress can be fattening, according to research on both humans and lab animals. For instance, women who said they were stressed out and/or had higher levels of cortisol (a hormone that rises in times of stress) had more visceral belly fat in studies conducted at the National Institutes of Health and elsewhere. This type of fat lies deep in the body, surrounding your organs, and has been linked to heart disease, diabetes and other illnesses. Even slim or normal weight women had more visceral fat than women who feel calmer and/or have lower cortisol levels. And when you’re stressed out, you might turn to cookies, chips and other junk food to unwind. That’s a recipe for obesity - at least it is in stressed-out mice, according to a study at Georgetown University in Washington, D.C.. You may be wondering how it's possible to test stress in mice. It's actually not much different from humans: Researchers placed the test mice with a more aggressive "alpha mouse" (sound a little like your boss?) for 10 minutes daily in a cage. They also made the test mice stand in cold water for an hour a day. The control group, on the other hand, led a relatively stress-free existence. Both groups of mice were given either regular mouse food or the typical American junk food diet. Only the frazzled mice that feasted on junk food became obese. They also developed high blood pressure, early diabetes and high cholesterol. In this Georgetown study, both cortisol and another chemical, neuropeptide Y (NPY), reached high levels in the stressed out mice. NPY sends the body the “store fat” message. This made evolutionary sense in times when stress often meant periods of famine; belly fat converts quickly to energy to fuel us. But now we’ve got the opposite problem - too much food - so we’re still storing “stress fat” which just sits deep on our bellies, growing even larger.