When broken down by occupation, obesity rates fluctuated significantly. For example, 12 percent of those employed as health care diagnosticians -- such as doctors, dentists, veterinarians and optometrists -- were found to be obese. That compared with nearly 39 percent of truck drivers.
Also on the high-risk end of the obesity scale were men and women involved in transporting and moving material (38 percent); protective-service workers, such as police, firefighters and emergency responders (33 percent); cleaning- and building-service employees (30 percent); mechanics and repairpersons (29 percent); administrative and clerical personnel (28 percent); salespeople (25 percent); and executives and managers (24 percent).
However, one issue with the findings, Bonauto said, "is that our measurement of obesity doesn't account for people who are very muscular and have a lean body mass."
"Being muscular tends to artificially inflate BMI," he said. "Firemen or construction workers face a lot of physical demands at work and tend to be more muscular."
Occupations associated with a low risk for obesity included natural and social scientists (17 percent); postsecondary school teachers (18 percent); those involved in non-diagnosing health care treatment (18 percent); architects, engineers and construction workers (20 percent); food prep workers (20 percent); lawyers and judges (22 percent); and computer scientists (22 percent).
Exhibit A: Truck drivers were classified as being the most likely to smoke and the least likely to consume a minimal amount of five or more servings of fruits and vegetables per day.
"Working with this information can get a little tricky," Bonauto said. "For example, I'd like to say our Washington numbers are easily comparable across states and regions. But there are employment variations, and we just don't have the data for other states yet."
Lona Sandon, a registered dietitian and assistant professor of clinical nutrition at the University of Texas Southwestern, in Dallas, expressed little surprise at the findings.
"While I wouldn't advise people to choose their career based on this, it's really no surprise that truck drivers top the list or that office workers chained to their desks have more issues with overweight and obesity," Sandon said.
"The work environment definitely can affect one's health," she said. "Employers who make an effort to encourage and make accessible physical activity and healthy eating can make a difference -- not just to their worker's waistline, but also to their bottom line. A worker who's healthy is a worker who's more productive."