In last year's This is The End, Seth Rogen's character Seth Rogen describes gluten as a blanket term for things that are bad for you, from calories to fat. While this isn't entirely accurate (it's actually a composite wheat protein), the definition seems to work well enough for plenty of people as a solid reason to go gluten-free.
On last night's Jimmy Kimmel Live, Jimmy decided to venture into gluten-free capital of the world Los Angeles to interview self-proclaimed GF-ers and ask if they, in fact, know what gluten is. The results are probably as you'd expect, but hey, nothing beats laughing at hipsters and people who don't eat pizza by choice.
Also, just because: