The recession that is shrinking workers' paychecks may also be expanding their waistlines, a survey showed on Wednesday.

One in 10 U.S. workers said they are snacking more during the day due to concerns over the economic situation, and nearly half complained of gaining weight in their jobs, according to a survey by CareerBuilder.com, an online jobs site.

It said 43 percent of employees surveyed reported they have gained weight while in their present jobs. A quarter said they gained more than 10 pounds and a sixth gained more than 20 pounds.

Admitting to eating habits that can contribute to weight gain, 39 percent said they eat out for lunch twice or more a week, and 12 percent buy lunch from a vending machine at least once a week, the survey showed.

Two-thirds said they snack at least once a day, including 24 percent who snack twice a day, it said.

"Weight gain in the office is common and is a result of a variety of issues including today's economic stress and poor eating habits," said Rosemary Haefner, vice president of human resources for CareerBuilder.com.

Only 9 percent of employees exercise at midday, the survey said, although a quarter of U.S. companies provide gym passes, workout facilities or similar benefits, it said.

Women are more likely than men to say they have gained weight, 48 to 39 percent, it said.

The online survey was conducted February 20 through March 11 by Harris Interactive among 4,435 U.S. adults employed full-time. The margin of error was plus or minus 1.47 percentage points.