Hi Christy,
I have a six yr old and a 2 1/2 yr old that has been a lot of work. But right now is the best time to let your child know that what you says goes. When you catch him throwing the food, get at his eye level and firmly tell him NO and continue until you feel you get your point across. Stay sitted beside him and reenforce your NO everytime. A lot of first time moms (including me) think that they absolute can't handle if their child is upset with them, but I had to be told many times, "Your their parent and not their friend." It's alright if your little one is upset with you for a little while, they will still love you in the end and you gain their respect that way too. Children need guidance. I hope this is a little helpful, also, I have started giving my children "V8 - Vfusion" to make sure they get their share of friuts and veg. and with meat just keep giving it. But for now at 13 mths., here and there doesn't hurt. Your doing a great job, just be consistant and follow through.
Quel