A person with a body mass index (BMI) of 30 or greater is considered obese. BMI is calculated as weight in pounds divided by height in inches squared and multiplied by 703.
A stressful job is associated with a bigger waistline, according to a new study of employees at a downsized company in upstate New York.
Workers with higher job stress were fatter than employees with less stressful positions. The stressed employees had a body mass index (BMI) that was about one unit heavier on average than that of their relaxed co-workers. BMI is a measure of height and weight that estimates body fat. For 5-foot, 10-inch person, one BMI unit is equal to seven pounds.
The findings are important in a time of widespread lay-offs, said Isabel Diana Fernandez, a nutritional epidemiologist at the University of Rochester School of Medicine and lead author of the study. In the study, workers left behind at the downsized company often complained of more stress and more responsibilities.
"I think the message is that we have to take care of the employees who've remained," Fernandez said.
How stress makes us fat
Work stress has long been associated with cardiovascular disease, obesity and depression, among other chronic health conditions.
Fernandez and her team wanted to investigate the combined effects of chronic job stress and short-term stress like the fear of unemployment. As part of a larger workplace health program, the researchers measured the BMIs of 2,782 employees, mostly white, middle-aged men with college educations. These employees had all kept their jobs through rounds of layoffs.
The employees answered questions about their diets, job stress and leisure-time activities. Short-term stress was estimated by measuring job insecurity, or the fear workers felt over the threat of more layoffs. Chronic stress was measured by the amount of control workers felt they had over their jobs and how heavy their responsibilities were.
The results showed no association between short-term stress and weight, but chronic stress was a different story. Workers with more responsibilities and less control had BMIs one point higher than their co-workers with low responsibility and high control, even after adjustments for known obesity risk factors like age, race and income.
However, the effect of stress on BMI disappeared when researchers factored in leisure-time physical activity and television watching. Using the Godin score, a measurement of how many times a person has done more than 10 minutes of exercise per day, the researchers found that for every drop in exercise frequency, BMI increased by 0.02 units.
Television was even worse for the waistline: People who watched TV for two to three hours a day had BMIs that were 2.37 units higher than people who watched TV for fewer than two hours. That's the equivalent of just over 16 pounds for the average 5-foot, 10-inch man, or just over 14 pounds for an average 5-foot, 4-inch woman.
The importance of job environment
Although the findings represent a moment in time and can't show causation, they suggest that stress at work makes people likely to fall back on unhealthy behaviors at home, Fernandez said.
"They go back home, and they only want to veg out," she said.
The findings, published in the January issue of the Journal of Occupational and Environmental Medicine, are important for employers as well as employees, Fernandez said.
She was co-author on another study in the same issue of that journal that found overweight and obese employees used more medical services and were absent more than lower-weight employees. The result cost employers an additional $201 a year per overweight employee and $644 a year per obese employee. The findings suggest that it is in employers' best interest to create a healthy environment, Fernandez said.
"People spend many, many hours at work, and in those hours we either move or don't move, or eat and have catered meetings," Fernandez said. "There are a lot of opportunities in the worksite to promote healthy behaviors."