Ask GR Anything: How does Kirby's stomach work?

According to our calculations, Kirby might have a gizzard

Ask GR Anything is a weekly Q%26A column that answers questions submitted by readers (as well as questions we're particularly curious about ourselves). Got a burning question about games or the industry? Ask us in the comments below and you may just get it answered!

This week’s question comes from GoPikmin, who inquired two weeks ago, “How about the science of Kirby's stomach if there is any?” Well, GoPikmin: No. There is no established science regarding Kirby’s stomach. So we’ll just have to create some! Get ready to take this junk entirely too seriously as we figure out the biology behind Kirby’s digestive track and make our journalism professors bow their heads in shame.

To begin with, a normal human stomach can hold only about four liters (or a little bit more than a gallon) of any type of material at one time, so there is definitely something interesting going on underneath that fluffy pink exoskeleton. Unless we’ve been drastically overestimating the height and girth of Mario, then the picture above proves Kirby has at least enough stomach area to hold a (small) grown man.

But with some serious practice, just about anybody can expand that stomach size considerably. Take Takeru Kobayashi, for instance. He made headlines all over the world in 2001, when he started smashing competitive eating world records in his rookie season. Most people assumed he was some sort of side-show with a stomach made out of waste from a nuclear reactor. But as it turns out, he just works really hard. For weeks before a competition, he’ll gradually eat more and more, stretching out his stomach to greater and greater sizes – a practice which doctors urge people never to attempt, as there is zero data on the long-term effects of purposefully distorting your own organ (seriously, don’t do it).

Above: Kobayashi after a competitive eating tournament

All the while he works out extremely hard to prevent fat from building up and restricting his stomach size. A 2007 study by the University of Pennsylvania wrote, “successful speed eaters expand the stomach to form an enormous flaccid sac capable of accommodating huge amounts of food.” Which is utterly disgusting, but it may be the clue behind Kirby’s special abilities.

Of course, Kirby might not be entirely human. The more likely scenario is that he’s some sort of sick genetic splice-up between a human, blowfish, and a bird. The blowfish comparison is obvious thanks to his inflation capabilities, and he’s vaguely shaped like a human. But why is he at all like a bird? Because he spits stuff up! Just like a momma bird, Kirby vomits back up his prey to serve further use.

So it’s possible that Kirby has two stomachs, like a bird (a few other animals have them as well; raptors, for instance). The important stomach is called the “crop.” It’s essentially a type of holding pouch where the animal can store food that doesn’t need to be eaten right away. Birds tend to use them to carry food back to their young. The pouch is very muscular, which helps them push the food back out without too much effort.

Above: Strange as it sounds, Kirby may have something in common with this rooster

So why is it necessary to compare Kirby to a bird? Because if he didn’t have a crop, things would get insanely messy. Stomachs are really nasty places. They contain large amounts of very strong acids that help digest things like meat and flesh. So it wouldn’t do well to swallow a guy like Mario, since his entire body would start to be burned away with acids down to its constituent chemicals.

The fun part about imagining Kirby with a digestive system like this is that he’d likely also have a gizzard. Gizzards are the true stomachs of birds (and other animals) that are used to grind up food. Some of them even have rocks inside to help mash up all the food. Which isn’t exactly exciting, but it does produce some horrifying visions of what happens when Kirby doesn’t spit out his prey.

If he swallowed the prey instead, they’d be slowly ground to death inside a muscle-organ filled with rocks. That would be very useful in helping Kirby sidestep many of the issues that beset competitive eaters, such as irritable bowel syndrome. So don’t mess with Kirby, unless you want the gizzard treatment.

Submit your own questions in the comments (or Tweet them to @sciencegroen) and we may tackle them for a future Ask GR Anything.

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