Aidyn went through the throwing stage too... mainly just his toys. But it becomes very annoying when he's throwing his die-cast trains around - they are capable of hurting someone, or going through the TV screen!
I actually adopted your technique (which I saw you wrote in an earlier post) about giving him one more chance, then removing the toy.
I find that as soon as we tell him not to throw, or get cross, he will throw more straight away, obviously a reaction of frustration.
I usually then try to move him onto a different activity, such as drawing, or musical instruments etc, until I find one that will distract him!

As for the throwing of food... I really cannot help you there.
I find Aidyn gets a lot crankier, and a lot less interested in his food if...
1. We strap him in the highchair.
2. We feed him at a different time to us.
3. He is eating something different from us.
He doesn't usually throw his food though... (yet!)
I don't know what to suggest... but I'm sure it is something that Jacob will grow out of.

I noticed that around the 2 year age mark, Aidyns throwing habits decreased by about 50% (this was when his sleeping/settling improved too), and a few months later than that he now does it even less! So hang in there Mel, I hope things calm down a bit really soon.