(Real Simple) -- Make smart food choices in an airport, at a rest stop and from a vending machine.
If you're at a stadium or concert arena, eat peanuts in a shell for protein and healthy monounsaturated fat.
Best picks: A small bag of plain pretzels -- not honey-mustard or any other flavor, which can add fat. "Pretzels are a satisfying, low-fat crunch without any trans fats or added sugar, and the single-serving-size bag means you get built-in portion control," says Keri Glassman, a registered dietitian in New York City and the author of "The Snack Factor Diet."
A close second is a small bag of peanuts or almonds, which is packed with protein that will fill you up, says Sarah Krieger, a registered dietitian in St. Petersburg, Florida. And the petite package prevents mindless eating from a big jar, which can be a danger at home.
Another good option: Whole-wheat crackers with peanut butter. While these little sandwiches can be higher in fat or calories than a serving of pretzels, "they have good fat and a little fiber," says Krieger, which will keep you fuller longer.
Worst picks: Potato chips, corn chips, and tortilla chips. They'll give you greasy fingers, but that's not the worst of it. Most snack chips are low in protein and fiber, and some are high in the two worst kinds of fat: saturated fat and trans fats. Real Simple: Healthy snacks for common cravings
Best picks: Low-fat yogurt. "It's loaded with calcium and protein, which will help you feel fuller," says Katherine Tallmadge, a registered dietitian in Washington, D.C., and the author of "Diet Simple: 192 Mental Tricks, Substitutions, Habits & Inspirations."
Can't find yogurt? A package of low-fat string cheese or even a small carton of skim milk can be nearly as filling, she says, especially when paired with a piece of fruit.
Another good option: Instead of buying packaged trail mix, which is full of sugar and fat, mix up your own from items sold at the quickie mart, says weight-loss counselor Molly Gee.
Start with a low-sugar dry cereal, such as Shredded Wheat or Cheerios, as a base. (Look for the mini cereal boxes.) Then add raisins or some other dried fruit and some nuts or small pretzels. Ask for a paper bag to mix everything together. "You've made a high-fiber snack that's crunchy, salty, and sweet," says Gee.
Worst pick: A cream-filled doughnut. Sorry, Homer. This high-sugar, high-trans fat combo has no redeeming qualities. Sure, you'll get a quick energy boost, but that will be followed by an equally quick drop in blood sugar, which will leave you feeling tired, cranky, and craving more sugar.
Best pick: A child-size popcorn (about five cups). With eight grams of fiber, it will satisfy your urge to munch and keep you feeling full. It's only 300 calories if you skip the "butter" (actually butter-flavored oil), says weight-loss counselor Molly Gee.
Another good option: Junior Mints. "There's nothing particularly good for you in them, but they're lower in fat than most of the candy bars at the theater," says registered dietitian Keri Glassman. Try to share the box, says Gee, since movie-theater portions are usually gargantuan.
Worst pick: Anything jumbo size or called a value combo. For instance, that large popcorn (20 cups) with extra "butter" and a large (44-ounce) soda add up to almost 2,000 calories. An entire movie-size package of Milk Duds has 595 calories.
Mall food courts
Best picks: A lean-turkey sub on wheat or multigrain bread with mustard and plenty of vegetables. The whole grains and vegetables have fiber to fill you up while providing vitamins and minerals. Turkey is low in fat, and the protein helps control your appetite, says registered dietitian Sarah Krieger. Or, if there's a sushi counter, order a salmon roll and some low-fat, high-fiber edamame. Fish is the protein source with the most nutrients for the lowest number of calories, says registered dietitian Katherine Tallmadge.
Another good option: A broth-based vegetable soup, such as minestrone or udon noodle. "You'll be getting a couple of servings of vegetables," says Krieger, "and studies show that the high volume of soup helps fill you up on fewer calories."
Stay away from milk- and cream-based soups, which are usually high in fat. Soups also tend to be salty, so skip them if you're watching your sodium intake.
Worst pick: General Tso's chicken with white rice. Where to start? This dish is deep-fried, often with dark-meat (fattier) chicken, and it's served with nutrient-barren white rice. When food-court Chinese is your only option, go for steamed or stir-fried mixed vegetables over brown rice. Real Simple: The secrets of thin people
Stadiums and concert arenas
Best pick: Peanuts in the shell. You'll get some protein and healthy monounsaturated fat, without extra fat from oil-roasting. Plus, shelling the peanuts slows you down, which means you'll realize you're full before you eat too much, says registered dietitian Keri Glassman. Just keep portion size in mind and aim to stick to a one-ounce serving, or 20 whole peanuts (with each shell containing two nuts).
Another good option: A hot dog. "If you're going to have one, this is the place to do it. Stadium dogs are usually all beef and higher in quality than ones bought on the street," says registered dietitian Sarah Krieger. Make sure you choose regular size over jumbo, and opt for ketchup or tangy mustard instead of chili or some other fatty topping.
Worst pick: Nachos with melted cheese. The only thing more frightening than the fluorescent orange of this concession-stand staple is the fat and calorie count: 350 calories and 19 grams of fat per six- to eight-chip serving. Not to mention the high sodium content. And let's be honest: Who stops at eight chips? Real Simple: How to read nutrition facts labels
Best pick: A protein or energy bar from a newsstand. "Look for one that has less than 200 calories and three or more grams of fiber," says registered dietitian Sarah Krieger. Avoid chocolate-coated bars, since these are often higher in fat and laden with sugar.
Other good options: If all you can find is granola bars, look for one with the shortest ingredient list -- that is, oats, nuts, dried fruit, honey, and not much else. Or tide yourself over with a small (one- or two-ounce) portion of unsalted nuts.
Another decent option, if it looks as if it hasn't been under a heat lamp for too long, is a slice of cheese pizza. "There's calcium in the cheese, the tomato sauce counts as a vegetable serving, and it's moderate in fat -- as long as you skip things like pepperoni," says Krieger.
Worst picks: Salty snacks, such as potato chips. When you're about to get on an airplane, the last thing you want to eat is something high in sodium, since it can make you feel bloated and dehydrated.
A candy bar is a close second. "If you have sugar on an empty stomach, you're not going to feel satisfied and you're just going to crave more sugar," says Krieger.
Get a FREE TRIAL issue of Real Simple - CLICK HERE!
Copyright © 2009 Time Inc. All rights reserved.