Christmas dinner: What a festive feast does to your body

Christmas dinner: What a festive feast does to your body Health & Fitness

Christmas is fast approaching, and Americans are preparing to knuckle down and stuff their faces, come what may. While the "average" calorie counts of Christmas dinners are often overblown, it's safe to say that most people eat richer food -- and more of it -- than they would during a typical meal.

But what does this delicious, delicious debauchery do to your body?

As explained by the American Chemical Society video above, your stomach is pretty resilient. It can easily stretch to a bit over a liter in volume -- about the size of a burrito. And according to the pathology reports of people whose stomachs have ruptured you can probably get about four times that much food in there before things get too dire. (Please don't try that.)

When you swallow food, you also swallow air. That fills up your stomach and intestines with gas, as well as actual food -- especially if you're drinking carbonated beverages, which release lots of gas inside you. As your stomach takes up more room, it literally squeezes the rest of your internal organs -- and squeezes that gas out, one way or the other. But with mashed potatoes and beer bubbling around in your distended stomach, it's no wonder that you start to feel a little uncomfy.

Don't worry too much about making your stomach explode: When you stretch your tummy to its limits, your brain starts to do everything it can to slow you down. That queasy feeling you get when you've just eaten a high-calorie meal is caused by hormones designed to keep you from picking up your fork again. Studies have found that this hormone is less effective when we eat quickly, so try to slow down your Christmas meal by actually talking to your family, or something crazy like that.

You might also suffer heartburn. Your stomach uses hydrochloric acid to break down food, but if you're eating more than usual, your stomach will produce more of it, and it irritates the lining of your stomach and esophagus. When you take antacids (which contain bases to neutralize your stomach acid), the chemical reaction releases carbon dioxide. So popping some TUMS can actually make you feel more full until you release that gas. You just can't win.

And finally, everyone's favorite Christmas feast side effect: snoozing.

You might think that your post-turkey nap is caused by the bird itself, but this is actually just a myth. It's true that turkey meat contains tryptophan, an amino acid that the body uses to produce serotonin -- a neurotransmitter that helps regulate sleep. But so do other foods. Cheddar cheese actually has more tryptophan than turkey does, and you don't conk out every time you eat grilled cheese (I hope).

The real culprit is the overeating. When you eat a ton of carbs (stuffing, mashed potatoes and sweet potatoes all at once will do the trick), your body releases extra insulin to keep your blood sugar in check. From LiveScience:

The massive intake of carb-heavy calories stimulates the release of insulin, which in turn triggers the uptake of most amino acids from the blood into the muscles except for tryptophan.

With other amino acids swept out of the bloodstream, tryptophan — from turkey or ham or any meat or cheese, for that matter — can better make its way to the brain to produce serotonin. Without that insulin surge, tryptophan would have to compete with all the other kinds of amino acids in the big meal as they make their way to the brain via a common chemical transport route.

So don't blame your basted bird: Blame all the side dishes you ate with it. And consider pausing before you dive into dessert.