Carnival has excellent food -- can't go wrong in that department.
Also, while both Carnival and NCL take 2 year olds in their youth programming, Carnival's counselors change diapers while NCL's doesn't. Thus, you can't leave the ship and have to be on call at NCL to come change your child's diapers if needed in the youth program.
So I'm leaning towards recommending Carnival to you.
Luisa Frey Gaynor
Family Cruise Editor