One night, your friend goes to a nice restaurant where the food is plated like small works of contemporary art and proceeds to scarf down their filet mignon like it's a post-blaze Crave Case from White Castle. Truth be told, your friend waits too long between meals and eats like a starving stray just about anywhere you go. Aside from making you look bad in front of the judgey maître d', is eating this fast bad for your health?
Before we get to a hard yes or no, here's a mini-lecture on the mysterious workings of the digestive system "from gum to bum," according to Lisa Ghanjhu, an associate professor of gastroenterology and hepatology at NYU Langone Medical Center. The more work you do with your teeth and stomach, she says, the less work needs to be done the further down as your food gets into the large and small intestines where the actual absorption of nutrients takes place.
The moment your friend crams a piece of steak the size of a baby's fist into their gullet, the mouth starts to secrete saliva that's chock full of enzymes like amylase that help you break down the food right there in the mouth as your teeth get to chomping it. It then travels down your esophagus, whose only purpose is to transfer food from mouth to stomach safely.
In the stomach, a whirlwind of stomach acids, more enzymes, and hormones like ghrelin and leptin (which tell your brain when you're hungry or full) join the party. However these hormones don't immediately reach your brain—it can take roughly 20 minutes for that ghrelin "full" signal to sink in, at which point you may have eaten twice as much as your body needs. If you've got massive chunks of barely chewed food sloshing into your tummy, it's going to take a lot more time and effort to break down your food, which can mean bloating, gas, and discomfort.
"The food stays in your stomach until it's ready to be passed off safely into your small bowel," Ghanjhu says. And if you pounded a burger and fries, it's going to take more work to break that down than, say, a vegetable stir fry. And even once it's broken down it doesn't all wash into your guts in a big tsunami of food particles. There's a tiny sphincter at the end of the stomach (before the small intestine) called the piloris—the hallowed gate through which your digested food moves along its merry way to becoming poop, the intestines and colon extracting nutrients as it goes.
"The piloris is the size of a quarter," Ghanjhu says. So no matter if you ate fifty dollars worth of food, it's only going to pass out of your stomach in tiny bits. Eating a meal too fast means all that food is going to be sitting in your stomach uncomfortably, since it takes several hours for a meal to be fully digested.
The Worst That Could Happen
It doesn't matter if that steak tastes like heaven—no meal is worth the risk of taking you those pearly gates. "The esophagus and the trachea are literally adjacent to each other by a thin membrane. If you eat too fast or talk and eat, you can inhale your food and choke," Ghanjhu says. Not only that, but food that's not well chewed can trigger an esophageal spasm and the food can get stuck in your throat, she cautions.
Better to practice a little mindful eating, she says, where you slow down, taste every bite, hold the food in your mouth and chew each bite numerous times. "It makes you really taste your food." If you "eat with your eyes," as she puts it, "your food hits a volume that triggers a hormone that says stop eating." If you miss that signal too and keep on eating your stomach gets stretched beyond capacity, and you miss out on the chance to actually enjoy your food.
What Will Probably Happen
If you eat too fast, too frequently, Ghanjhu says, "You can get reflux and venting up of material from the stomach. It's basic physics." Acid reflux can cause a burning sensation in the throat (that some people often mistake for a heart attack). It can also manifest as a feeling of being unable to swallow properly, or feel as though there are air bubbles or pressure in your throat. Acid reflux can also show up as burping, nausea, and general gassiness. Especially sexy if your friend is doing his usual food-shoveling on a date. He might even taste bile—a sweet second chance to chew food he already ate.
While eating for pleasure is a perfectly acceptable reason to devour your food, there's the more important issue of getting the nutrients you need. "The more work you do with your teeth and stomach, the less work needs to be done in the small bowel, and the better your absorption," Ghanjhu says.