You may be right, there.  Near my house we have an all-you-can-eat buffet with sushi; compared to fats I never "get my money's worth" in their opinions* -- I have literally gotten comments about it (e.g. "what, you're stopping now" etc.).  Thankfully I don't hang out around fats much so it's rare but when it does happen my mind just screams "yes, I'm stopping because I am full and don't want to feel and look like shit." * The fats, not the buffet owners; the owners love me.