It's become trendy to maintain a gluten-free diet, even for people without allergies, but it's apparently not as trendy to have any idea what gluten is.

Earlier this week, Jimmy Kimmel—who's pro-gluten because he's pro-pizza—sent a crew to a popular L.A. workout spot to see if people could explain what they're not putting in their bodies. You won't be at all surprised how it went.