Women who have demanding jobs — ones with significant stress — are at increased risk of gaining a considerable amount of weight as they grow older, according to Swedish researchers.
No such risk was observed among men with stressful jobs, however.
“We were able to see that high job demands played a part in women’s weight gain, while for men there was no association between high demands and weight gain,” said Sofia Klingberg, the study’s lead author and a research in community medicine and public health at the University of Gothenburg, in a released statement.
The study was published Friday in the International Archives of Occupational and Environmental Health.
Stress and weight gain
As background information in the study points out, psychosocial factors, such as mental stress, are known to contribute to unhealthful behaviors, including unhealthful eating that can lead to excess weight.
Stress also increases the amount of cortisol circulating in the body. High amounts of that hormone have been linked to the accumulation of visceral fat (the body fat that’s stored around the liver, pancreas and other major internal organs in the abdomen), as well as to a reduction in lean body mass.
Given those findings, it’s not surprising that job strain has also been linked to obesity-related diseases, such as type 2 diabetes, heart disease and stroke.
Klingberg and her colleagues wanted to take a closer look at the relationship between work-related stress and major weight gain, particularly over a long period of time.
For the study, the researchers analyzed health data collected from a representative sample of 3,872 Swedish men and women. The participants had their body mass index (BMI) calculated on three different occasions over a 20-year period, either from age to 30 to 50 or from age 40 to 60.
On each of those occasions the participants also filled out questionnaires that assessed their work-related stress. Those questions asked them about job-related psychological pressures, the pace of their workload, and whether they felt they were given enough time to complete their work responsibilities.
They were also asked questions aimed at assessing how much control they felt they had at their jobs, such as whether they were personally able to choose what they did and how they did it, as well as how often they learned something new and whether their job required imagination or advanced skills.
At the time the participants entered the study, 27 percent of the women and 39 percent of the men were overweight or obese. Ten years later, 33.5 percent of all the women and 26 percent of the all the men had increased their body weight by 10 percent or more — an amount the researchers defined as a major weight gain. After 20 years, 48.9 percent of the women and and 43.7 of the men weighed at least 10 percent more than they had at the start of the study.
The people most likely to have experienced a weight gain of 10 percent or more were those with a low degree of control over their work. That finding applied to both men and women.
High levels of work-related stress were also linked to weight gain, but only for women. Women who spent 20 years in high-demand jobs gained, on average, 20 percent more weight than women in low-demand jobs.
How much education they had didn’t explain this association, the study also found.
Limitations and implications
The study was observational, so it can’t prove a causal relationship between work stress and weight gain. Also, the participants’ level of job strain was based on their self-reports, which may or may have had hidden biases.
In addition, all the participants were Swedish. The findings might not apply, therefore, to people living elsewhere, including here in the United States.
Indeed, obesity is much less prevalent in Sweden than in the U.S. In 2016, 36.2 percent of American adults were obese compared to 20.6 percent of Swedish adults, according to the World Health Organization.
Still, the findings support previous research that has suggested a correlation between chronic stress — of any kind — and weight gain, particularly among women.
“When it came to the level of demands at work, only the women were affected,” said Klingberg.
“We haven’t investigated the underlying causes,” she added, “but it may conceivably be about a combination of job demands and the greater responsibility for the home that women often assume. This may make it difficult to find time to exercise and live a healthy life.”
FMI: You can read the study in full on the website for the International Archives of Occupational and Environmental Health. You can also take one of the study’s self-tests about job stress on the University of Gothenburg’s website.