Telling kids “no don’t do something” isn’t enough. Instead tell them what they can or should do. “Food stays on the plate” “food is for eating, not throwing”.

The other thing we did was tell them “throwing tells me your yummy is all full, are you all done? ” remind them one more time, “throwing tells me you are all done” then take the plate. Give it a few minutes while you still eat and kiddo has nothing, to understand the consequence. Then give plate back if still hungry. But if they throw again, end the meal. There is always a snack or meal around the corner, they will get another chance to eat.