You worked hard to land that dream job, and now you're looking forward to watching your bank account grow. But instead, it's your dress size that's been growing. Quick doughnuts on the way to work, snacks between meetings, and late-afternoon trips to the vending machine are all taking a toll on your waistline.

If any of this sounds familiar, you're not alone. According to a survey, 47 percent of U.S. employees say that they've gained weight since they started their current jobs. How can you take control of your health and start fitting back into your favorite power suit again? Follow these five easy tips.

1. Bring your lunch. Bring a healthy sandwich, salad, or leftovers, instead of dining at your company cafeteria or a nearby restaurant. Not only will you cut calories; you'll save money, too.

2. Make the most of your lunch hour. If your workplace has a gym, use it. Health experts recommend 30 minutes of exercise at least five times a week. If there isn't a gym, go for a brisk walk, or jog outside. Just bring a comfortable pair of sneakers.

3. Step away from the goodies. Pass on the cakes, cookies, and other sugary snacks your coworkers tend to bring in, and avoid the vending machine completely. According to the survey, 35 percent of employees say they snack at work at least three times a day, and 43 percent admit to eating less healthy snacks at work than at home. For a healthy on-the-job snack, bring low-fat yogurt, fruit, or vegetables. To add flavor and protein, dip your apple or celery sticks in peanut butter.

4. Drink water all the time. Forget the lattes and sugary sodas—a large fountain soda can contain as many as 400 calories. Drinking water will make you feel full without costing you any calories, so try to keep a bottle with you at all times.

5. Start moving. You can make more active choices all day long, not just on your lunch hour. Health experts recommend 10,000 steps a day, so if you drive to work, park as far away from the building as possible, and take the stairs instead of the elevator. Put down the telephone and walk over to your coworker's desk if you want to chat, and start wearing a pedometer so you can strive to hit the 10,000 mark.