Stress, tension and excess belly fat are all stewing in the same pot and the binding ingredient is the hormone, cortisol.
CAVEMEN WOULD have much use for the hormone, cortisol, but in the modern world, researchers now say this fight-or-flight response hormone, is out of place and does nothing more than contribute to flabby bellies especially among women who are slim.
The theory is that it's all in the body's intricate, environmental defence system. A stressor is perceived in the environment, this urges the brain to get on the alert, releasing corticotropin-releasing hormone (CRH) in preparation for the fight-or-flight response.
Almost simultaneously, other things also happens in the body - the lungs pull in more oxygen, the pupils dilate, appetite reduces and digestion shuts down.
Two other important hormones - adrenalin and cortisol - are also produced in the fight-or-flight response. They help the body's mechanism to rally to its rescue quick energy from its stores of carbohydrate and fat. The glucose released into the blood stream, in turn sets off an excessive release of insulin.
The important part of the fight-or-flight mechanism for weightwatchers, however, is that, when the stressful event has passed, the adrenalin dissipates but cortisol hangs around to help the body regain its homeostasis.
The researchers say that the effect of the lingering cortisol is an increase in the appetite so that the energy stores supposedly lost in the fight-or-flight response can be replaced. The problem is that there is often no fight or flight in response to stress; recharging the body's stores is therefore unnecessary. Sustained stress, the theory is, keeps cortisol in action and keeps the appetite running high. The excessive insulin released in the process, also signals the body to store fat in the abdomen.
It was a study conducted by U.S. research scientist, Dr. Elissa Epel, that supported this new thinking on the role of cortisol in weight gain (published in the journal Psychosomatic Medicine). She studied 59 women - one-half of them fell into the group of the so-called apple-shaped people with fat sitting in the waist and with a high waist-to-hip ratio; the other half, had their fat accumulating around the hips, fitting into the low waist-to-hip ratio group.
The women with high waist-to-hip ratios appeared to be more vulnerable to cortisol's effects and it was the slim women, not the overweight women, who suffered most from this stress hormone. Similar findings were produced from studies done by the U.S. National Institutes of Health - Dr. Pamela M. Peeke. Fat in the waist, central fat, is apparently very sensitive to the stress hormone, cortisol.
This complicated biology seems to fit quite nicely into everyday experience, at the end of a bad day, it is the easiest thing to reach for some 'comfort food' but only now, it may not all be the psychology that has gone haywire; overeating may just be the natural response to the body's physiological hardwiring.
