Whether you while away the days parked in an offce chair, shuttling between point A and point B making deliveries, or melting on the blacktop working road construction, every job has its own nutritional land mines. Business lunches. Missed meals. Weird hours. Here's how to avoid those diet traps, keep your body in top form, and still get your job done.

Problem: You're desk-bound

Challenges:: Take your pick--there's the hours spent face-to-face with the computer, the stacks of mind-numbing documents, and those coma-inducing meetings. You could cope by downing tubs of coffee and wearing a path to the company vending machine, but that dose of sugar just makes matters worse, sapping brain waves and tanking your energy reserves.

Solution: First things first: When you work in an office, make sure you never skip meals, especially breakfast. Going for hours without eating muddles thinking and wrecks productivity. "Regular meals provide your brain and body with the fuel it needs to run at top efficiency," says Elizabeth Somer, R.D., author of Food and Mood. Keep meals small and include protein whenever you can (milk, eggs, peanut butter, cheese, tuna, beef, and chicken are all ideal). Protein stimulates the production of dopamine and norepinephrine, two chemicals that help keep your brain at its sharpest.

Problem: You spend a lot of time on the road

Challenges:: The most convenient places to grab a meal--airports, greasy spoons, and fast-food joints--are also the worst. Research shows that a steady diet of away-from-home food can increase girth even when you don't overeat. In a nine-year study of 16,000 men, Harvard University researchers found that for every 2% increase in calories from trans fats--the type of fat used to make french fries, doughnuts, and other common restaurant fare--men added nearly half an inch to their waists. "Trans fats could reduce insulin sensitivity, which may increase abdominal obesity," says Pauline Koh-Banerjee, Sc.D., the study's author.

Solution: If you have to order from a menu on a regular basis, look for a way to bulk up your fiber intake with things like fresh fruit (especially berries), whole grains, and vegetable soups. Studies show that men who add just 12 grams of fiber a day to their diet may lose a quarter of an inch from their love handles, without making any other changes to their diet. Still not getting enough fiber? Buy a bottle of chewable, sugar-free fiber capsules, like the orange-flavored ones made by Fiber Choice. They taste great--almost like candy--and can help further bulk up your diet.

Problem: You do shift work

Challenges:: One week, you're on the job from 11 p.m. to 7 a.m.; the next, you're working days--making it hard to get enough shut-eye. "Chronic sleep deprivation can drastically increase a man's risk of gaining weight," says Phyllis Zee, M.D., Ph.D., a neurologist and director of the Sleep Disorders Center at Northwestern University.

An ongoing lack of sleep can slow your metabolism, Zee explains. "It also alters the brain's ability to know when you're starting to feel full while eating," she says. (Maybe that's the reason for all those late-night feeding frenzies.)

Solution: Lots of planning. If you don't have access to restaurants or cafeterias because of a late-night schedule, make up for it in advance by eating a hearty, high-protein meal before heading to work. Zee also suggests packing as many healthful snacks as possible, like fruit, string cheese, yogurt, or individual packs of cottage cheese. "It'll help you avoid pigging out when you get home," she says.

Problem: You have a high-stress occupation

Challenges:: Because emergencies are impossible to plan for, you never know when you're going to get to eat a healthy snack, let alone a meal. Plus, you're likely under an extreme amount of stress. A recent research study at Ohio State University shows that when you eat foods like a double-cheeseburger with fries during times of stress, your body has a much harder time clearing artery-clogging triglycerides (i.e., fat) from the blood. And that can make those bad foods even worse for you.

Solution: Magnesium. It's not a magic bullet or cure-all, but increasing the amount of magnesium in your diet can help keep your blood pressure and cholesterol in check, as well as help prevent insulin resistance--a forerunner of type-2 diabetes. You could pop a supplement, but you're better off eating magnesium-rich foods instead. Peanut butter on whole-grain bread, salads made with dark, leafy greens and topped with wheat germ or sunflower seeds, black beans, oatmeal--even oatmeal chocolate-chip cookies--are all good choices.

Problem: You sweat at work

Challenges:: Lots of physical activity may seem like an excuse to eat as much as you want--but that's a mistake. "You can't assume that being active will protect you against weight gain or chronic conditions like heart disease or cancer," says sports nutritionist Nancy Clark, M.S., R.D.

Solution: "Front-load your calories," advises Clark. "The best way to prevent weight gain is to try eating the bulk of your calories during the early part of the day instead of at night, when it's easiest to indulge." Since your job can take you all over town, make a mental note of the restaurants and fast-food places with the healthiest options (beef-and-bean burritos, soft-shell tacos, chili, or turkey subs are all great high-protein options). When you pack food, think about what you're taking and when you're going to eat it. "You're better off packing a couple of sandwiches instead of one sandwich with cookies and chips," says Clark. "That way, you can eat two healthy lunches--one at 11 a.m. and another at 3 p.m., for example--and cut down on some of your less-healthy snacking and nighttime binging."