Bend, Ore. (CNN/Money) - Richard Gomes, 24, managed to get through college without putting a single pound on his 5-foot 8-inch frame.

But three years -- and 15 pounds -- after going to work for a Los Angeles public relations firm, Gomes realized he would have to make a conscious effort to keep his hands out of the office candy jar and steer clear of Jack in the Box on his way home from work.

"After sitting behind a desk all day and sitting in traffic on the way home, you're exhausted," said Gomes.

"I'm not the only one who gained weight after starting the job," he added. "It's a common complaint in our office."

Dare we say, it's a common complaint in nearly every office in America.

Blame it on technology. For a growing number of deskbound employees, work means moving only fingers and lips for eight, ten, twelve hours a day.

"Forget about exercise, some people don't even have the opportunity to move from their desks," said Toni Landau, a leader for Weight Watchers in New York.

"The excuse I hear most is 'My day is so busy,'" said Philip Goglia, founder of Performance Fitness Concepts in Santa Monica, Calif. With no time to exercise or eat well, many workers regard their expanding waistlines as just a symptom of a job well done.

For most of Goglia's clients, overeating is not the problem. It's skipping meals during the day and then making up for lost meals by overeating at night.

If you do skip breakfast or lunch, or just need that 3:00 pick-me-up, there's no shortage of fatty, sugary foods to consume. Every office seems to have a drawer or bowl of candy, continuously stocked by a colleague whose efforts are both loved and loathed. What you can't find in there, you can buy in the break room vending machine.

If that's not enough to tip the scale, business lunches, dinners and drinks surely will. "I like to say the most fattening food is free food," said Landau. "When you're on an expense account it's difficult to not opt for the gourmet foods."

What to do? The best way to control what you eat, say experts, is to eat three meals a day -- preferably something you've brought from home -- and keep healthy snacks on hand. By keeping your blood sugar on even keel, you'll be less tempted by the junk food around you.

Experts say it's also important to understand why you eat. In the office, boredom and stress are frequently mistaken for hunger.

"When I get stressed out I go for microwave popcorn. I need something that crunches," said Bonnie Russell, who runs the watchdog site FamilyLawCourts.com. Russell's added 20 pounds to her slim frame since starting the site in 2001. Stress, she says, is the reason.

"When you get stressed out your body triggers adrenaline and puts you off balance," said Bruce Van Horn, a certified public accountant who now runs Yoga for Business. Our ancestors needed this adrenaline to run from predators, he said. Since we can't run from angry bosses and demanding clients, we treat nervous energy with food, drink and cigarettes.

As an alternative to munching, Van Horn recommends deep breathing, walking and any other activity that will help calm you during times of stress.

Not every office is a minefield for weight gain. At SparkPeople, a Cincinnati-based company that coaches goal setting, employees who consistently exercise for an entire year receive $1,000 bonuses. In the last year, four of the firm's 25 employees have lost 30 to 40 pounds; an intern lost 50 pounds and took to running marathons.

The Adams Group, a South Carolina-based marketing firm, is also giving the office a healthy makeover. Twice a week employees clear the conference room for Pilates class.

They are also encouraged to stretch at their desks, and take advantage of gym subsidies and free chair massages. The break room, meanwhile, is stocked with fresh fruit, low-fat granola bars and other alternatives to vending machine fare.

"Companies are finally figuring out that lifestyle has a lot to do with their increasing health costs," said Peggy Sheagren, manager MFit Health Promotion, a division of the University of Michigan Heath System. When employees are healthy, they're more productive, have fewer sick days and don't cost as much to insure.

Back in Los Angeles, Gomes has managed to shed 10 pounds since March, and is going to the gym for the first time in two years.

He admits, though, that old habits are hard to break.

"I had Jack in the Box last night," he said. "I just couldn't resist."