In my house, we rarely have snacks. I do this so my children will be nice and hungry by the time they sit down and therefore less likely to play with their food.
If they ask for a snack specifically, I will give it to them to encourage communication (unless they ask for the same candy over and over again). It’s important for children to learn that they can assert their needs and get results from it.
For the most part, though, I send the message that if they don’t eat what they see in front of them at the table, they just won’t eat.
I also don’t give them drinks at the dinner table. It’s nothing but mess and headache! All day and night they beg for milk, juice, and water; they can go a few minutes at the table without a drink. If they really want it, I’ll give them a sip out of my glass.
As for throwing food: if one of my kids throws their food on the floor, I scoop it right up and plop it back on their plate. It only takes a few dog hairs in their mouths for them to learn their lesson.
That might sound harsh, but think of it this way: I’ve seen them lick every toy they’ve ever owned; I’ve seen them suck on rocks; they ate part of a pop tart they found on the playground before I could take it away; and just tonight, my three-year-old thought it would be funny to bite my husband’s toes. Not to mention all the food they find between couch cushions, under car seats, and under the kitchen table. If they can survive all that, they certainly can survive whatever is on the kitchen floor.
Besides, I don’t want them to learn that acting up by throwing food on the ground is a way to escape from their problems. No matter what they do to their food, they still have to eat it.
I’m also pretty strict at the dinner table. It’s a perfect time to teach children valuable skills in behavior, including politeness, etiquette, handling undesirable situations (i.e. food they don’t like), taking other people’s feelings into consideration, and general family socializing.
It’s not a time to play with their food. Some days they aren’t mature enough to handle the responsibility of a fork, and on those days I might just feed them myself.
You can reduce waste from your kids, but not eliminate it completely. They don't know how to be responsible with their food yet, so there will occasionally be an inedible scrap here and there. Luckily, we have a dog for that.
Hope that helps! Good luck with your kiddos!