depending on the snack and how far expired it was you would probly get very sick
you would have explosive dioreaH
You would get sick.
The most likely outcome by far is that nothing at all will happen out of the ordinary.
Not much, ketchup is very acidic, and therefore even after a long time on the shelf, bacteria will still have trouble growing in it.
she would have to stay there for every food she ate
Nothing
You die.
Nothing good!
YOu die
you would eat fish
it would survive
If you ate human poo, (which you shouldn't) you would most likely get very sick.