Despite the common belief that stress causes people to gain weight, according to recent research stress has little long-term effect on weight.
Researchers analysed 32 previously published studies conducted mainly in the last 2 decades in UK. All the studies reviewed assessed participants' stress levels and then followed the subjects over time to see whether there was a relationship between stress and subsequent weight gain. Most followed participants for one to seven years, but a few followed people for up to 38 years. Some of the studies focused on participants' levels of work stress, while others gauged general life stress, which includes anything from major trauma like experiencing a serious illness or a divorce, to feeling overwhelmed by daily problems.
Majority of the studies analysed showed no association between people's stress levels and their weight gain over several years. Overall, 69 percent of the studies found no clear association between stress levels and weight gain. One-quarter linked higher stress levels to greater weight gain, and the remaining 6 percent found that greater stress was related to less weight gain over time. When the researchers pooled the results of all the studies, they found a modest association between higher stress levels and greater weight gain. In general, the connection was stronger among men than among women - an interesting finding since it is popular belief that stress has a greater impact on women's weight.
But the above findings do not necessarily mean that stress cannot have a significant influence on some people's weight. The average effect of stress on weight might be small, but there could be wide variations among individuals. Some people may increase their food consumption under stress, while others may stop eating and lose their appetite. In addition, different types of stress - whether associated with work, caregiving or specific life events - might have different effects on weight gain.
One of the limitations of this review, according to the researchers, was that it could not examine the role of psychological disorders - the included studies focused on exposure to stress, and not, for example, whether a person developed depression in response to that stress. Therefore the general message is that, based on the best current scientific research, stress is not likely to play a major role in increasing body weight or obesity for most people. It could be that some people are more affected than others but rather little is known about this at present. Therefore there is need for more research into the factors that might explain why one person puts on weight in response to stress and another does not.