Ah, the holidays! The parties, the presents...the packed-on pounds. It's not just socializing that does your diet in during the festive months; it's also the circadian rhythms of the season. "We're programmed to eat more because our ancestors generally had less food in the winter," says Ingrid Frey, an exercise physiologist. "Now we've got plenty, but we're still stuck in that 'feast or famine' mode." But don't despair (or run out and buy elastic-waist pants): We've identified the eight biggest seasonal threats to your waistline and gathered expert advice on how to avoid them.

Trap 1: Family Feasts

While it's always great to see Aunt Betty, it might not be so great to eat her butter-laden food. "Watching calories around the holidays is tough because food ties you to you family and friends," says Kathleen Zelman, MPH, R.D., and director of nutrition for WebMD Health.

Strategic sidestep: Contribute a healthful dish (roasted vegetables, whole-grain bread, a lean cut of meat) to your clan's holiday spread, or offer to cook at least one meal if you're visiting for more than a few days, suggests Frey. When you can't control the menu, practice diplomacy. Don't throw a hissy fit over the lack of fruits and veggies, but stand firm when Grandma tries to force-feed you that extra helping of greasy mac and cheese. Also, be a good guest and burn some serious calories by helping to clear the table, pitching in with household chores or running errands — anything to avoid sitting and nibbling.

MORE HOLIDAY TIPS


Trap 2: Abundant Alcohol

People love to belly up to the bar around the holidays. But alcohol can pack a double whammy, delivering up to 400 calories per drink and eliminating inhibitions — which could lead to overeating as well as dancing on tables.

Strategic sidestep: Choose nonalcoholic drinks such as seltzer and cranberry juice. Drink from the same type of glass used for mixed drinks, complete with a lime and a swizzle stick, and you'll avoid the "Oh, you're not drinking?" hassles. If you do hit the sauce, stick to light beer or wine, nurse each drink long as you can and alternate with a glass of water. Whatever you do, skip the eggnog — even without the booze, it's 300 calories per cup!

Trap 3: Bountiful Buffets

It's the season of smorgasbords, which can leave guests feeling bloated and depressed. "Almost everyone overeats at buffets," says Zelman. "There's just too much variety — and too much food — to practice restraint."

Strategic sidestep: Eat a healthful mini meal (a sandwich or a bowl of cereal) before going to parties, and wear something that's snug around your waist, says Zelman. When you hit the buffet, load up on veggies, salad greens and sliced meat, then add a few decadent things on top. The key is to think "dinner" rather than compiling a mountain of snacks. Prepare a plate for yourself, then sit down away from the buffet to eat. When you're finished, go socialize — and forget seconds.

Trap 4: Sugar Overload

Experts know that humans are genetically wired to seek sweets and that chocolate contains mood-boosting chemicals. But understanding the science doesn't help us get through the season of candy and cookies without putting on five pounds.