The Science of Getting Festive

We tend to gain a little weight—usually somewhere between one and two pounds—over the holidays. Many of us lose part of that weight in the new year, but about half of our holiday weight gain proves difficult to shake.

Clearly we eat more of certain foods—often rich ones—over the holidays. That’s hardly shocking, and in fact it’s fine to indulge in moderation. You want to enjoy the extra care people put into food prep at this time of year, not police every morsel you eat. But by understanding some of the possible reasons for overeating over the holidays, you can treat yourself to tasty food without the regrets—or the turkey coma.

For starters, the more people we dine with, the more we eat. Researchers call this “social facilitation”—and it only seems to happen when we’re dining with our nearest and dearest (not with strangers). The effect is so precise that for each additional person at the table, we take additional bites. We also tend to match our eating patterns to whoever we’re eating with. If your fellow diners are tucking in with gusto—as they usually are at a festive feast—it’s a lot harder to put down the fork, dab your mouth with a napkin, and say, “No more for me, thanks.”

Another possible reason we go a little overboard (or think we do)? Good old gender dynamics. We associate holiday romance with mistletoe dangling from doorways. But the dinner party table may be where our biology really shows, especially when there’s a mix of men and women pulling up a chair. Cornell researchers found men tended to eat a lot more at a buffet-style meal when they were dining with at least one woman as opposed to just other men—probably in order to impress her. (Because what woman hasn’t thought, “A man who eats 92 percent more pizza when we’re together? Sold!”) Women, on the other hand, ate the same amount regardless of the sex of their eating partner(s). But when they ate with men, they believed they ate more, they felt rushed and that they overate.

Finally, the sheer variety of dishes at a holiday dinner may prompt us to chow down, down, down. The crunchy spheres of Brussels sprouts, the cloud-like swirl of mashed potatoes, and the velvety gravy are all so different. Research shows that when we’re faced with a greater variety of foods, we often eat more—but this extra intake doesn’t make us feel as full as it should. In one study, some participants received three kinds of appetizers, while other participants got only one kind of appy. The participants who had access to a variety of appetizers ate more—and yet their hunger didn’t decrease any more than the one-appy participants’ hunger did.

How to host a healthier gathering

Keep unnecessary noise to a minimum during meals. You don’t have to go full Silent Night: a big gathering should get a little boisterous. But there’s no need to add the blare of background television or cranked up music. Why? Being able to hear the sounds their food makes as they chew it—every crunch and chomp—can help your guests eat less. Researchers call this “the crunch effect.” (Note that other meal-related sounds—like the sizzle of oil in a frying pan or burble of gravy simmering on the stove—haven’t been shown to have the same effect.)

Remember that what you serve first at a meal matters. Researchers found that starting a meal with soup led people to eat 20 percent fewer calories. Of course, that’s contingent on that soup being reasonably low-calorie—heavy, cream-based concoctions need not apply. Don’t worry: you can still wow your dinner party guests sans chowder. Go for a chunky or semi-puréed soup: researchers have found people rate those thicker soups as tastier and more visually appealing than straight up broth with veggies.

Cooking with spices like ginger and cayenne or using herbs like fenugreek and holy basil can help improve digestion, blood sugar balance, and stress response—all of which can make for a more pleasant dining experience (and may even have a positive effect on body weight over time). For a nightcap that will set your guests up for a night of sweet slumber, try a cocktail or mocktail that contains tart cherry juice. Tart cherry juice contains impressive levels of melatonin, an important sleep hormone, and has been linked with enhanced sleep quality and duration.

Holiday gatherings can involve more physical activity than migrating from dining room chair to living room couch. Why not round up your family for an after-dinner walk? If you’re exchanging gifts, ask yourself: will this gift empower better health? Sure, we all deserve a few holiday indulgences, but sprinkle fitness trackers, active video games, and gorgeous, must-flaunt-at-the-gym water bottles into the gift-giving mix.

How to have a healthier holiday as a guest

The decision to eat mindfully starts way before you get to Grandma’s dining room. If you’re heading to a family dinner, you probably have a good idea of what will be on offer. Choose your treats ahead of time: will it be Uncle Darren’s pumpkin pie or Mom’s Christmas pudding? Stash a few breath mints in your pocket so that once you’ve decided you’ve had enough to eat, you can chew one. You won’t want to wreck that minty fresh feeling with a second helping of stuffing. And make a mental commitment to stay an arm’s length away from the candy bowl on the coffee table. There will be plenty of other, more special food on offer.

Healthy holiday gatherings have as much to do with crawling into bed as they do with sitting down at the table. Research shows we tend to stay up past our regular bedtimes during the last half of December. Late nights can lead to greater calorie consumption—especially when there are plenty of after-dinner snacks on offer. If you’re a houseguest over the holidays, get settled into your room before diving into the festivities. That way you can slip away when it’s bedtime instead of waiting for your host to have a free moment to show you to your room at the end of the night.

Make sure you’re nailing your nutrition and supplement basics even when you’ve got a hundred holiday engagements to attend. Omega-3s and probiotics are superstars all year long, and the holidays are no exception—especially considering that both have been linked with healthy changes to body weight. Ensuring adequate magnesium intake could also help you battle the bulge now and in the coming year. Magnesium deficiency has been associated with more abdominal fat, insulin resistance, and impairment in energy metabolism. Leafy green veggies are good whole food sources of magnesium. So reach for those steamed greens at dinner, or start the day with a spinach-based smoothie.

Supplements for the season

You might also want to nab a few special supplements for the season. If you’re destined to eat a rich dinner, digestive enzymes could save you from the dreaded bloat. These supplements help break down the food we eat (the enzyme lactase, for example, tackles the lactose in dairy products). This reduces the chances of having uncomfortable post-dinner gas. In addition, 1 g of activated charcoal taken at least 30 minutes before a meal and then again after the meal has been associated with reduced intestinal gas; just make sure you know its possible interactions before taking it.