Can Ghost eat?

[Fred Waldrop]

No: HPFGUIDX 90663

I have just finished re-reading HP SS/PS for the umteenth time, and 
once more the same question has came to my mind.
Can Ghost eat? Well, I should say, can Ghost eat for the first 
hundred years or so after they have died?

The reason I ask this is, in SS/PS, chap 7 (the sorting hat), page 
123 US, it says: 
"That does look good," said the ghost in the ruff sadly, watching 
Harry cut up his steak.
"Can't you - ?"
I haven't eaten for nearly four hundred years" said the ghost.

Then in CoS, chapter 8, (the deathday party), page 133, it goes on 
to say:
              Sir Nicholas De Mimsy-Porpington
                  Died 31st October, 1492

Which is 500 years since his death.
If the year before he had not eaten for "nearly 400 years", did he 
eat during the first 100 years after his death?

Fred