Be on smart-eating guard at the airport.
Avoid loading up on greasy burgers and fatty muffins before your flight. Pack (or pick up) a sandwich on whole wheat, some nuts, and an orange, and save your splurges for the good stuff, like a buttery croissant at a Paris caf? or creamy lobster bisque on the coast of Maine.
Play good food cop, bad food cop.
Once you get there, go ahead, have the fettuccine Alfredo. When I order something decadent, I eat just half of it and then swap plates with my husband, who agrees to order the healthier—yet still tasty—grilled salmon.
Pretend you're a food critic.
Nothing tastes as good as the first bite, so approach vacation fare as though you're on a tasting mission. Instead of ordering your own dessert, try a forkful of your friend's cheesecake or a lick of your kid's ice cream cone—and then stop.
Steer clear of binge zones.
Avoid places where gorging is a main attraction (e.g., cruises and Las Vegas). Going to an all-you-can-eat buffet is a guaranteed diet buster. There may be healthy choices, but you're a lot stronger than I am if you can pay $18.95 and then bypass the bacon, eggs Benedict, chicken cordon bleu, scalloped potatoes, and flourless chocolate cake for a plate of mixed vegetables and grilled chicken.
Go for a condo.
Studies show that the more frequently you eat out, the more likely you are to gain weight, because restaurants load you up with hidden calories. If possible, book accommodations with a kitchen; it may cost slightly more, but you'll save a bundle by cooking. Aim to prepare all your breakfasts, plus either lunch or dinner each day. With that in mind, make a grocery list on the plane. Tear off a section for each family member so that you can stop at the store, and divide and conquer, on the way to your destination.
Don't be a beach bum.
If you're still in planning mode, consider a walking or cycling tour of California's wine country or Vermont's fall foliage. (Most active-travel companies will accommodate all abilities.) No matter where you travel, try not to equate chilling out at the pool with lounging all day. The more calories you burn splashing around in the water (about 200 an hour*) and dancing the night away (about 300 an hour*), the less you'll have to worry about the ones in your pi?a colada.
* Calorie burn based on a 150-pound person.