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.