Wow! I ran across this video of a woman with lip plates drinking water. It is fascinating to see how incredibly large her piercings are stretched (both upper and lower lips). I can also see that there has been no thinning of the tissue, which often occurs when stretching is done too quickly.
It looks like drinking is a bit of a challenge, and I imagine eating is too, but I'm completely fascinated. It isn't a modification I'd want for myself, however. The little 14 gauge hole in my lip is just fine for me.