Over half (55%) of those polled say they’re too chubby, and 44% attribute that to their work. One in four (25%) have put on more than 10 extra pounds. Women (49%) are more likely than men (39%) to report having gained weight, but the reasons cited by both sexes were the same. “Sitting at a desk all day” tops the list at 53%, followed by 45% who say they’re “too tired from work to exercise.” About one in three (36%) blamed “eating because of stress.”

There’s plenty of evidence that too much sitting is unhealthy, and the sheer numbers of “knowledge workers” glued to their desks for hours on end are one reason obesity in the U.S. is climbing. Moreover, while consumers seem more health-conscious than ever (witness, for instance, the current 30-year low in sales of soda pop), almost 80% of those who told CareerBuilder they’ve gained weight admit they snack a lot at work—presumably not on, say, carrot sticks.

Still, it’s clear that a chief cause of work-related weight gain is stress. Consider: 77% of employees who say they’re heavier than they used to be describe stress in their jobs as “extremely high.” The report notes that “workers who say they have extremely high on-the-job stress are 53% more likely to say they’re overweight than workers who say they have extremely low stress.”

Scientists have been busy researching the connection between feeling under intense pressure, especially for prolonged periods of time, and having to buy bigger pants. It seems, for instance, that stress boosts the body’s output of a hormone called cortisol. Among other not-so-great effects, cortisol makes people crave foods high in fat, sugar, or both.

One of the best antidotes is exercise, and the CareerBuilder survey mentions that employer-sponsored “wellness programs,” aimed partly at encouraging people to exercise more without leaving the premises, are on the rise. Yet only about a quarter of the employees in this survey have access to amenities like on-site gyms—and, of that small group, fewer than half (45%) actually use them.