I don't know how many are in your party - but by DD (14) and I can almost always split an entree at the nicer restaurants and have plenty to eat. If you split them they aren't any more expensive then a fast food meal in the park.
As far as the fast food - my favorite is Flame Tree Barbeque in AKL. I'm not really a big barbeque fan and I loved theirs!
<img height="200" src="http://www.wdwinfo.com/sites/disdebbie/Mickeyandus.jpg">
Debbie, Bill & Becca with unidentified friend - July, 2000