Going from Satiated to normal (presumably other similar changes as well) interrupts walk mode. It probably should not, unless you become hungry. There are very many walking interruptions already.

I don't see any reason why someone would want to interrupt walking merely because satiation goes down. Bloated -> satiated might qualify, if you are carrying that blink dog corpse and are running out of holy water. I have never found that to be an issue, though, at those times you just don't use the extended walk command. :)