We were in WDW for a week in December with my 13mo. They really do a lousy job for toddlers. The food the adults were having was not usually something he would eat, and we threw out half the kids meals each time.
He's used to roasted or grilled chicken and took one bite of their kid's chicken nuggets and flat out refused them afterward. I did get salads with chicken a few times and that chicken he was okay with.
They need to add a toddler selection to their menu. To say that kids under three eat free is completely false, if you actually want to feed your kid you have to purchase a child's meal but they aren't geared towards toddlers. For the kid's pasta, we needed maybe half that, obviously a 13mo is not going to eat as much as 5, 6, 7 or 8 yo.
I had yogurt and cheerios in the room from our garden grocer order, bought bananas, apples and hard boiled eggs in the gift shop. Vegetables were pretty much a lost cause, as he's not up to raw carrots yet (he loves them steamed) and that seemed to be their usual and only choice.
The counter service in Japan has a side of vegetables and you can request no teryiaki sauce.
If you have buffets scheduled those are your best bets but there are reports of being charged if you make your toddler their own plate. You may put the food on your own and then give it to them at the table.
Liberty Tree Tavern charged $5 for a plate of buttered noodles that he took two bites of. 'Ohana served him the children's options and did not charge us.
You may be able to order just applesauce at counter service places which I didn't realize until the end. In some cases it would have been better than anything other choice they had (for us).
We don't feed my son french fries or hamburgers, if you do it will be a lot easier.
We're going back in February and I'm going to be bringing in more food for him.