More than half of U.S. workers say they are overweight

As a result, the pounds have piled on. Welcome to corporate America.

More than half of U.S. workers think they're overweight, according to a new CareerBuilder survey. That's not much of a surprise, since more than a third of American adults are obese, researchers say, and that could rise to half of adults by 2030.

The survey also shed some light on who is most likely to gain weight at work. Basically, if you're an older woman in management who sits at the computer all day, get to the gym immediately.

Here are the types of workers most likely to gain weight:

Managers: About 44 percent of people in management said they gained weight in their jobs.

Workers over 35: Some 40 percent of employees in this group gained weight.

Women: About 46 percent of women gained weight compared with 33 percent of men. One reason for the difference might be that men are more likely to exercise at the gym compared to women.

Desk job holders: Workers in information technology, government, financial services and heath care fields were more prone to weight gain.

Employees in the West. Although the western states constitute one of the healthier sections of the U.S., about 44 percent of workers in the region say they've put on weight. The Northeast isn't far behind, but the South and the Midwest were somewhat heather.

The extra pounds are weighing on company bottom lines, too. Overweight workers tend to have more health problems, which can lower productivity. And so companies are trying all kinds of tricks to make employees healthier.

In Silicon Valley, some companies have installed treadmill desks on campus. Other companies give cash rewards to employees who participate in annual health assessments and who meet specific health goals.

Federal rules cap the amount of financial rewards at 20 percent of a worker's health insurance premium, according to Bankrate. For an employee whose health insurance costs $5,615 a year -- which was the 2012 average -- that saves $1,123. And Obamacare will likely push that maximum higher.

Unfortunately, many of those corporate wellness programs just don't work, according to a survey from the Rand Corp. The company's research into these programs found that participants only lost about one pound a year and didn't see any reduction in cholesterol levels. The cost savings for companies were statistically insignificant.

In other words, your company's carrot-and-stick programs may not do a whole lot. Anyone who wants to lose weight must do the hard work themselves.

CareerBuilder gives the following tips for staying healthy at work:

-- Don't eat all the treats people bring into the office. As tempting as that plate of peanut butter brownies may be, just walk on by.

-- Try to sneak in some exercise here and there. This doesn't have to be a sweaty-headband kind of workout, either. Instead, get off the bus a stop early, or take the stairs instead of the elevator.

-- Get off of your chair. Go find a co-worker and talk instead of sending an email. The more you can move around the office, the better.

-- Pack your lunch. Calorie-heavy restaurant meals and fast food are packing on the pounds. Bringing a lunch from home isn't just healthier, it's cheaper, too.

-- Ask about company health benefits. See if there are discounted gym memberships available or other sorts of wellness perks. Many employees say they have no idea what their companies offer.