Yes he can. Luffy has a bottomless stomach. He can eat and eat and eat and eat all daaaaaaaaay looooooong. We've seen this time and time again.
Here is luffy eating an entire trolley load of fruit in mere seconds:
[qimg]http://a.imageshack.us/img24/593/luffyfood2.gif[/qimg]
And read pages 3-4
http://read.mangashare.com/One-Piece/chapter-539/page002.htmlLook at the amount of food he consumed
Even then, he only had a 2-3% chance of actually surviving. Luffy survived through sheer force of will to live so he could save Ace
Luffy hates Pizza.