Thursday, 17 July 2014

Stress Slows Metabolism and May Cause Weight Gain

It seems that we now have another factor to worry about in addition to our diet and exercise routine when we're trying to maintain a healthy weight. Most of us know that a fatty meal is bad for our health, but some new research has shown that a stressful event on one day and a fatty meal on the next is especially bad for our metabolism and may trigger increased weight gain.

Steak and French fries, a meal that is generally high in fat;
 a public domain photo by Petr Kratochvil
Researchers at The Ohio State University tested 58 women with an average age of 53. The first step in the test was to give each women three standardized meals in a day. The women were then told to fast for twelve hours. On the next day they travelled to the study centre and completed a questionnaire about any stressful events that they had experienced during the previous day. The women were then given a meal containing 60 grams of fat, which they had to eat in twenty minutes.

The researchers measured the levels of oxygen and carbon dioxide in the women's breath, which were related to their metabolic rate. They also performed blood tests to measure the women's glucose, triglyceride, insulin and cortisol levels. Glucose is also known as blood sugar and triglycerides are a type of fat. Insulin and cortisol are hormones. Insulin is released as a response to glucose in the blood and triggers glucose absorption by cells. Cortisol is a hormone released during stress. The tests on the women were performed regularly over a seven hour period.

The results of the tests showed that women who experienced one or more stressful events on the day before the fatty meal burned an average of 104 calories less than people who experienced no stress. They also had a temporarily increased level of insulin and triglycerides in their blood. Interestingly, these results were true whether the fat was saturated or monounsaturated, even though monounsaturated fats are generally considered to be much healthier than saturated fats.

The researchers say that the observed body changes could potentially lead to a weight gain of almost eleven pounds in a year. We already know that on their own stress and fatty meals are unhealthy; when the two factors occur in quick succession, they seem to be even worse for us! More tests need to be done, including tests in men to see whether the results are the same in them as in women.