Honestly, I don't believe its fair to say "all you can eat" unless its true. Otherwise, you should put some type of detailed limit.
But attempts must have been made and probably continue.
I went with my Vietnamese colleague to an all you can eat sushi place in Savannah after we spent two weeks doing hurricane response when I was still in the Coast Guard. This dude ate 32 rolls of sushi, and the old lady running the place loved him. At a certain point, I think she just wanted to see how many it would take before he tapped out. I think I ate ten or twelve rolls, and just sat there in awe while the dude just kept shoveling food into his mouth. To be fair, we'd been working 20 hour days for two weeks and the ship was running out of food before we pulled into port.
Later on, found out that same dude cheated on his wife, then found out his wife was pregnant, they tried to work it out, she had a miscarriage, and he filed for divorce two weeks later. Fun times