S.G.
Hi Becky,
I have not gone through this. Fortunately both my girls are pretty good eaters. But I would say it is not that your son is so hungry, it's that he knows if he complains you will get him up and feed him. Anything to stay up a little longer! Maybe on the nights he doesn't eat, offer him a snack 10 minutes before bed. Tell him he can have (whatever you decide) now or nothing because he will NOT be getting out of bed to eat. Then if he chooses to eat nothing stand firm and don't get him up.
Not really sure if that will work, but I think that is what I would do.
One more thing, I find that putting kids back to bed the super nanny way works really well. The first time you say something like "you may not get out of bed for food, you had your opportunity to eat and you did not. Good night and I love you." Everytime after that you simply put them in bed without saying a word.
Good luck! S.