It's just another form of unhealthy addiction like smoking, drugs, drinking, etc...  they crave food because it brings them pleasure.   Being satiated has nothing to do with it (obviously, LOL).  I can't imagine having such a miserable fucking existence where I have to use food as a drug or an escape; they get away with it because our western society doesn't punish them for it like we do with most other bad vices.  We need to fucking ban shit food, raise their insurance rates through the roof, charge them triple for hospital visits (or better yet, just deny them non-critical health services), make their pathetic lives as difficult as possible until they get the message that treating your body like a dumpster is no longer acceptable.