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Stress from Negative Life Events Linked to Obesity in Women
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More stress in a woman's life may widen her waistline, a new study reveals.

Researchers found that middle-age and older women who experienced more stress from major life events were more likely to develop obesity than women who did not report any stressful events, according to the study, which was presented today (Nov. 13) at the American Heart Association's Scientific Sessions meeting in Anaheim, California.

These findings suggest that psychological stress in women may be linked with  increased odds of obesity, said study author Dr. Michelle Albert, the director of the Center for the Study of Adversity and Cardiovascular Disease at the University of California, San Francisco. [9 New Ways to Keep Your Heart Healthy]

Psychological stress could come in the form of a traumatic life-changing event, such as the death of a child, a life-threatening accident or illness, or a serious physical attack, Albert told Live Science. The stress could also be due to negative life events that occurred within the past five years, such as being unemployed for longer than three months or being robbed or burglarized, she said.

Stress and obesity are both considered risk factors for heart disease, but little is known about the relationship between stressful life events and obesity in women, Albert said.

So, to investigate how stressful events may influence weight changes in women, the researchers looked at data collected from about 22,000 women, with an average age of 72. The women were taking part in the Women's Health Study, a long-running study in the U.S. examining health risks in postmenopausal women. 

About 23 percent of the women in the study were considered obese.

All of the participants answered questions about whether they had experienced a major traumatic event in their lifetime, along with questions about negative life events within the past five years.

The researchers found that women with one or more traumatic events in their lifetimes had a greater chance of being obese that those without any traumatic events.

But it was not just a major stressful experience that was linked to obesity: The study found that the more negative life events a woman experienced, the higher her odds of being obese.

Women who had four or more negative events in recent years were 36 percent more likely to be obese than women with no stressful events. Women with one negative event were 17 percent more likely to be obese, according to the findings.

The study did not investigate why stressful experiences in a woman's life could increase her likelihood of weight gain. One possible explanation is that stress may increase appetite by increasing the production of the hormone ghrelin, often referred to as the "hunger hormone," Albert said.

Stress may also lead to changes in lifestyle habits, such as reduced physical activity or increased alcohol consumption, or it could trigger changes in eating habits, such as snacking more frequently or consuming a poor-quality diet, Albert said. She also noted that emotions may play a role: Feeling stressed out can lead to loneliness or make someone more prone to sleep problems, anxiety and depression. 

One of the limitations of the study is that researchers only looked at a five-year span, so it's unclear at what point during women's lives they developed obesity.

Future studies can examine whether negative life events affect weight gain over time, and if these weight changes are linked with cardiovascular problems, such as heart attacks and strokes, Albert said.

The findings have not yet been published in a peer-reviewed journal.

Originally published on Live Science.