Riddle me this

exp(x) said:

Are you constantly eating? What I don't understand is how the dead live if they eat nothing.

Because if they are dead, the need to not eat to remain dead? Perhaps if the dead exist in some realm of the living (dead) then if they eat say, an apple, or a twix, all the sugar will either catapult them back into the living (and so be alive) or will be such a shock to the system - they will merely fade away into nothingness. . .