It would be my honor to make a critique of the food selection that you have when you're visiting the theme parks. As long as you will not have to wait in line, I have been very impressed with the overall selection and nutritional menu, especially Disney. They know how to make tuna salad Sandwiches with low mayonnaise and very minimal oil, and then you can load them up with vegetables just like they do at Subway. Grilled chicken sandwiches are probably one of the most popular items at all of the parks, that's a healthy choice as long you should don't put any Condiments that are bad for you. They sell fresh fruits so you could for instance grab a whole apple real quickly while you're walking down the street at one of the vegetable and drink stop markets. There are some good quick foods that you can grab that one of the Food Courts or in the stores. For instance, something to eat very slow that is filling would be sunflower seeds. The only problem with sunflower seeds at Disney, is are you allowed to spit them on the ground are not! You better go at the apple!
Let me make some eating suggestions for those at Epcot Future World. Not in the world Showcase of Restaurants, just in future world. Electric umbrella restaurant is located in innoventions east. Coral reef restaurant is a winner inside the Seas with Nemo and Friends. Garden grill is the most popular Quick Service restaurant The Land. Sunshine seasons Food Court is very good with lots of dishes in the land.
Onion is great when paired with the spices of the sausage. I love the slight sweetness of caramelized onions on just about anything. I like the choice of stone-ground mustard on top of anything. I found the best polish sausage in Orlando at polonia-restaurant.com cafe in Longwood. Get a beer with a polish sausage, one with generous pour. Hot mustard is a great choice for the sausage as a condiment. Beer is pricey with dogs at Disney. We went for late night drinks and loved the sharisushilounge.com bar.