If you’re like most office workers, you’re likely to be working in a sedentary position at your desk for more than eight hours per day. Does that give you a higher risk of obesity? The Centers for Disease Control and Prevention (CDC) has released a study that analyzed which professions have the highest — and lowest — obesity rates in Washington State.

The study reviewed 37,626 people working in the state of Washington by using the Behavioral Risk Factor Surveillance System — the largest telephone healthy survey system in the world — during odd numbered years between 2003 and 2009. The researchers studied demographics, occupational physical activity levels, how many fruits and vegetables these workers consumed, leisure-time physical activity, as well as smoking levels.

The authors found that overall, there was a 24.6 percent prevalence of obesity amount the study’s respondents. This is lower than the obesity prevalence in the U.S. as a whole, which is 35.7 percent, according to the CDC — meaning over one-third of American adults are obese.

Workers in protective services were 2.46 times as likely to be obese than people who worked in “health diagnosing” conditions, the CDC reported. In perhaps what is obvious, people who had physically demanding jobs, ate their fruits and vegetables, and took part in exercise outside of work (leisure-time physical activity), were less likely to be obese.

“Obesity prevalence and health risk behaviors vary substantially by occupation,” the CDC wrote. “Employers, policy makers, and health promotion practitioners can use our results to target and prioritize workplace obesity prevention and health behavior promotion programs.”

So who was most at risk? Protective service employees and truck drivers had the highest rates of obesity among the 28 occupation groups as well as transportation and material moving workers and cleaning and building service workers. The CDC found that when it came to proper intake of fruits and vegetables, healthcare professionals — especially nurses — met or exceeded their daily nutritional consumption. Eating more fruits and vegetables was associated with lower rates of obesity. Nurses, food service workers, engineers, lawyers, natural scientists and social scientists, and finally, health diagnosing occupations like doctors, had the lowest obesity rates.

“Prevalence ratios for obesity were significantly higher among workers in older age groups than among workers aged 18 to 29, among male workers than among female workers and among workers with less education than among workers with a college degree or higher,” the CDC wrote. The report also found that obesity prevalence in Washington State workers indeed increased every two years, meaning it’s possible that Americans are getting fatter.

However, it’s not necessarily the occupation that makes the worker obese. The study has limitations, the CDC is quick to note; it’s a cross-sectional study, and correlation doesn’t equal causation. Likewise, using BMI (body mass index) as a measure may not be entirely accurate, as BMI doesn’t distinguish between fat and lean tissue mass. Firefighters and policemen, for example, may have a higher BMI because of increased muscle mass, but the study wasn’t granular enough to identify these details.

The CDC urges employees and employers to improve workplace health, by incorporating time for exercise breaks, healthy food, and bringing fitness areas into the workplace.