I actually write a weekly blog on the matter! The pinterest page for it is
here, and my homepage for it is
here.
As for some general tips:
-I rely heavily on the Chili that littleroo has mentioned from CHH. It's on the menu already vegetarian, so it's ready to order and it's super cheap! Get a side of fries and/or steamed broccoli with it for a filling lunch.
-Any restaurant will accommodate your diet even if you want to make a special request. It's easiest to do at a Table Service location, but even at a Counter Service restaurant, just as the cast member at the podium to help you come up with a meal that fits your tastes.
- I like to plan ahead. Keep in mind specific things you want to eat everyday before you start your day so that you don't feel frustrated when you are hungry. For example, for a day in Magic Kingdom start out with breakfast at your resort with some Mickey Waffles and fruit. Know you are going to head over to quick service lunch at the new Be Our Guest for the Quinoa Salad Entree, then plan on Columbia Harbor house's chili for lunch!
-WDW's menus are always changing! Did you know Tamu Tamu Refreshments in AK just added a vegetarian option?! I wrote a blog post about it
here.
Hope this helps! Sorry to have so many "plugs" for my blog, but I have so much information on the topic that it's easier to send you my links!!