I'm with kanga. I use booster seats too and put the food right on the tray. I also give small portions and if they eat everything without throwing it on the floor they get more. I have one dcg who is currently throwing everything off her tray, so I literally give her one piece of food at a time. Saves on the clean up and I dont waste as much food. If she eats it, she gets more, if she throws it on the floor, I wait a few more minutes then offer it again. If she keeps throwing it on the floor, then I don't offer her anymore food. Lately, she hasn't been eating or drinking much due to this (and other problems) but we are slowly making an improvement.