Researchers have made us believe worry, anxiety and lack of sleep push us to gain extra fat; however, a new study suggests otherwise.
According to The Irish Times, a study looked at 36 previously published reports and found no clear link between stress levels and gaining weight.
Led by professor Jane Wardle at the University College London in the United Kingdom, the study compared and analyzed well-controlled studies and found that there was only a modest association.
The reviewed studies were performed during the 1990s and 2000s, with a majority of those following participants from one to seven years.
In an email to Reuters Health, doctor Andrew Steptoe, another researcher in the project said, “we assumed that there would be a substantial association between stress and obesity, since the popular view is that stress contributes to weight gain.”
“But when we looked carefully at well-controlled scientific studies, effects were surprisingly small.”
Sixty-nine percent had no clear link in weight gain and stress levels, 25 percent with higher stress levels gained more weight, and the remaining six percent found greater stress had to do with less weight gain.
The results also revealed that those with higher stress levels did gain more weight, but it was more prevalent among men than women.
Michael Riddell, an associate professor at York’s faculty of kinesiology and health sciences, found the research compelling. In an email to Excalibur he wrote “this is a meta-analysis done on all published studies in humans on perceived stress and obesity. A weak positive association was actually found.”
“This is not that surprising as several variables influence the development of obesity and not all people overeat when they are under stress. Some, in fact, undereat.”
While weight gain caused by stress is relatively small, there can be wide individual variations, says Steptoe.
The type of stress might also have an effect on weight gain, including work and life events.
Annaliese James, a fourth-year student studying at York’s Schulich School of Business, believes stress may not be the main reason, but that it can be a source.
“Personally, the stress I have encountered has been a major factor in weight loss; however, I acknowledge the fact that other people may be affected differently because of differences in personality, lifestyle, type of stress, experience with stress – and the list goes on,” said James.
In July 15, 2009, an article published in the American Journal of Epidemiology concluded that stress is linked to heart disease, increased risk for cancer and weight gain in the American population.
This study, “Psychosocial Stress and Change in Weight Among U.S. Adults,” is considered the first to look at weight gain and several stress types such as job demands, payment of bills, strained relationships, depression and anxiety.
The study also found that differing levels of stress affected women’s waistlines. For men, stress due to the lack of authority and skill discretion at work led to weight gain.
Those with higher body mass indexes (BMI) were more likely to be affected by psychological stress, than those with a lower BMI.
The researchers in the American study suggest that when coping with life situations, change in eating behaviours will happen and will eventually cause changes in weight.
To help stressed workers, stress reduction is vital, including access to weight-loss programs at work, exercise programs and a flexible schedule.
The relationship between stress and weight gain are still being studied. Steptoe said, “It could be that some people are more affected than others, but rather little is known about [stress and weight gain] at present.”