My brother does that with whatever I'm drinking too. He just picks up my cup when I'm not looking and drinks it down until there's nothing but trickles at the bottom them puts it back and insists that he didn't drink it all cause there's still some left.
that is exactly what my brother does, then he goes 'that some good stuff man, can you make me one? I want one just as good as yours and mine won't be like that' and then I make him one after he took 2 great bites of mine. >.<' but hey he's my bro...
Ah. Well, if anything, it looks like you know the way to his heart! Hopefully you can cook, but if not that's what restaurants are for.
And yes, I myself can say that many men, especially young ones, have alarming appetites. I once ate a 2 for $20 meal at Applebee's and still had room left over. I have control over my impulses when people share with me, but many of us don't. A little tip, break off a piece of what you want to serve to him instead of handing him the whole thing.