Hi M.,
I had the same problem with my son, and it might not be a popular solution for many moms, but I fed my son for a while until I felt he forgot about how much fun throwing food was. I would keep him in the high chair, with the food away from him, and feed him for about a month (it takes 27 days to change a habit) then put the food back on the high chair and wean him back to feeding himself. he would feed himself things that he wouldn't throw.
Now, he did great for a while, then decided to start throwing his food again, and I would feed him again. He even did this behavior when he was in preschool because he liked the attention!
This happened off and on until I felt he was old enough to understand that it is not ok (2 1/2 - 3), then made him clean it up himself. of course he wouldn't do a great job, but he got the idea of how much work it was to clean up and he was responsible for his mess. He would then occasionally throw something after giving me that "I'm going to throw this food" smirk.
It finally ended after a few spankings when he was 4( I certainly don't recommend spanking 16 mo). Now he is 5, It took a while, but feeds himself just fine and doesn't throw anything anymore.
For now, it will make your life easier if you just expect him to throw, plan ahead for prevention or consequences. Don't let it make you crazy...he may like that reaction, too (mine did).
K.
I am a now SAH, homeschooling Mom in Middlesex County with a very energetic, fun-loving, determined 5yo BOY who thinks everything is a game.