J.B.
We have had the same problem. What we have found that works is this - Caleb gets two warnings:
1) Do you not want your food? "yes, I want it" Then quit throwing it.
2) Do you want me to take your food? "no, I eat it" Then quit throwing it. if you do it again, I'm taking it away.
If he does it the third time, take the food and stick to your guns. 2 year olds don't really need a whole lot to eat - so don't worry that your're going to starve him or anything. And don't give him anything else to eat until his normal snack/meal time. We've only had to do this with Caleb twice and he cried and screamed - boy was he mad! But then he knew that we meant it and we've never had to go past the 2nd warning since.
Good luck!
J.