Here’s What Eating a Thanksgiving Feast Actually Does to Your Body

Thanksgiving is a time for gratitude, good-will and gluttony. While many people enjoy the holiday feast with abandon, some dieters and healthy eaters stress over the idea of consuming a huge number of calories in one sitting.

But is it worth the worry? Here’s what eating one enormous meal actually does to your body, according to experts.

The short-term effects of a big meal

When you consume lots of food, your stomach has to physically expand to accommodate the additional volume, potentially leading to some discomfort, says Dr. Stephen Juraschek, an internist and primary care physician at Beth Israel Deaconess Medical Center in Boston. When that meal includes lots of starchy dishes, like those in a typical Thanksgiving spread, your body also experiences a sudden spike in blood sugar as carbohydrates are converted into glucose, Juraschek says. Cholesterol markers, blood pressure and fluid retention may also increase as your body processes fats and salt, he adds.

But “those spikes should come down, usually within a couple hours,” and the vast majority of people won’t experience physical symptoms worse than bloating, heartburn or headaches, Juraschek says. People with chronic health conditions, however, have more to consider. People with diabetes, for example, should carefully manage their blood sugar, and those with a history of vascular problems or hypertension may be at higher risk of complications related to elevated blood pressure or fluid retention, Juraschek says.

Eating a huge feast also recruits extra energy to your digestive system, says registered dietitian Dawn Jackson Blatner — and that’s probably to blame for your post-dinner grogginess, not the often-cited tryptophan in turkey. “You can only do so many things with your physical body, and when you put a lot of food in, that is going to take energy for digestion,” Blatner says. You may even notice that your extremities are a little cold, since extra blood is diverted to the digestive system and away from the rest of the body, she says.

The long-term effects of a big meal

The good news: You’re unlikely to see any lasting effects from your mega-meal, no matter how many calories it contains.

“There’s 365 days in a year. If you eat three meals in a day, we’re talking about over 1,000 meals in a year,” Blatner says. “What you’re doing for a holiday here and there is not going to have any lasting impact on health and weight if you’re getting back to your normal healthy-ish eating afterward.”

Juraschek agrees, and adds that your body may not even be able to store everything when you occasionally overindulge. “Yes, you’ll get excess calories from the meal, but there’s only so much that you can absorb in a single sitting,” he says. “It’s really more of a longer-term pattern of eating that we worry about.”

The bottom line

In an ideal world, you’d exercise portion control and opt for a produce-heavy plate on Thanksgiving, but both Juraschek and Blatner say you shouldn’t stress too much. Still, there are a few ways you can protect both your health and comfort on Turkey Day, the experts say.

First of all, resist the urge to skip breakfast, since eating a light morning meal may kickstart your metabolism and keep you from getting ravenous before dinnertime, Juraschek says. And when you do feast, take your time. “Slower rates of eating result in a greater sense of satiety from the brain,” Juraschek says. “If you slow down the rate of consumption, you’ll feel full faster, before you go back to get more.” Leisurely eating also gives your body time to digest, potentially reducing discomfort. Blatner also recommends drinking plenty of water, which can aid digestion and flush out excess salt.

It’s also a good idea to take a stroll after dinner, Juraschek says — not only because you’ll burn a few calories, but also because it’s a nice activity to do with loved ones. And above all, Juraschek says, that’s what Thanksgiving is about.

“If [overeating] is truly just a one-time thing, then it’s okay,” he says. “I don’t think most people should worry too much, and should really focus on enjoying the time with family.”