Stressed Out: The Behavior and Biology of Stress

As the everyday stressors of life seem to be continually on the rise – from work and unemployment concerns to family and health issues – so does the collective waistband of the U.S. population. Is there any physiological relationship between stress and weight, or is it all in our heads, so to speak? The answer is a little bit of both.

The fact that stressed−out people often overeat is no secret. We’ve all done it at one time or another – reaching for a bag of chips to calm our frazzled nerves is not a completely foreign concept to most people. Studies have shown that men and women both pack on pounds in response to stressful life circumstances, though the triggers may be very different.(1) One study found that for women, the stressors that were linked to weight gain were more varied than for men, and consisted of everything from family to financial problems. For men, on the other hand, lacking the ability to make decisions or to be creative at work was associated with more weight gain.(1)

But there is an additional reason that we tend to gain weight when chronically stressed, and this has to do with how the metabolism is affected by the presence of cortisol over the long term. Over time, high levels of cortisol in the system can wreak havoc on the way the body metabolizes energy.

Aside from feeling soothed by that bag of potato chips and other forms of comfort food, the urge to eat after a stressful event actually has a more “legitimate” physiological component to it as well. The drive to eat after participating in a stressful event occurs in large part in order to replace one’s depleted fat and protein stores. But while replenishing these energy stores might have made sense after a calorie−consuming skirmish in olden times, it makes less sense in response to the stress induced by completing one’s income taxes. Though mentally exhausting and indisputably stress−inducing, let’s face it: there is not the same need to “replenish” one’s fat stores after a battle with one’s taxes. These extra calories can particularly add up when one is under repeated stresses over a long period of time.

But there is an additional reason that we tend to gain weight when chronically stressed, and this has to do with how the metabolism is affected by the presence of cortisol over the long term. Over time, high levels of cortisol in the system can wreak havoc on the way the body metabolizes energy. As mentioned earlier, the hormone is in charge of increasing blood sugar levels to replenish lost energy stores. But when long−term stressors are present and cortisol levels remain elevated, blood sugar and therefore insulin levels also remain high. This situation not only leads to unwanted weight gain, but, if left unchecked, can ultimately lead to type 2 (adult onset) diabetes.(2) If you find that you are over−eating chronically, particularly in response to certain stressors, it’s a good idea to step back and determine whether any of these factors can be removed from the picture, or if not, what a more effective approach to dealing with them might be.