What happens to your stomach when you overeat

Your stomach can handle overeating, but it gets better at stretching if you do it all the time


November 21, 2018

Piles of mashed potatoes. Turkey. Stuffing. Gravy over all of it. Plus: sweet potato casserole. Obligatory salad. And yes, pie.

“Just try a little of everything,” you say, as your plate fills to capacity.

Your empty stomach is the size of a soda can

At this point, your empty stomach (assuming you’ve fasted all day to justify Thanksgiving) can hold between 6.5 and 10 ounces of food—about the size of a soda can. Which is definitely not going to cut it.

Thankfully, our stomach can stretch to more than double its “resting” size.

The brain tells the stomach to unfold

The stomach is lined with folds called rugae. When it’s time to eat, the rugae unfold like an accordion, relaxing and expanding the stomach.

We can thank the sweet pain of anticipation for this unfolding. As the aroma of caramelizing onions (they always get me) wafts from the kitchen, the brain tells the stomach to get ready. The stomach doubles in size, even before any food comes down the esophagus.

How big can the stomach get?

Depending on the person, the stomach can hold between two and four liters of food, though most people start feeling full after one liter, or about 4 cups of food. So, when we overeat, our stomach simply expands to accommodate all that mush. Despite what it might feel like, there are very few cases of the stomach actually exploding. Your gag reflex usually kicks in before that happens.

What overeating all the time does to the stomach

Overeating once doesn’t lead to a perpetually baggy, stretched stomach. Our stomach returns to its normal size after eating. Which explains why studies show that thin people and obese people have about the same size stomachs. However, if you regularly overeat, your stomach will develop the ability to extend more than it needs to as a habit, which can add to the cycle of overeating. It takes 10 to 15 minutes for the stomach to smash whatever you’ve eaten into liquid and sent it the small intestine. Some studies show that if you cram a lot of food into your stomach in that time period, you can trick yourself into thinking you’re still hungry. The theory is that hormonal triggers tell the brain to stop eating as food moves from the stomach into the small intestine. That’s why experts say slow eating is a thing we should do. What you’re eating matters. Fatty foods take longer to digest in the stomach, so it takes longer for the full feeling to kick in when you’re eating them.

But if you’re looking for something to feel grateful for this holiday, may I humbly suggest the stomach? It’s flexible enough to accommodate our excesses.