Breakfast we did Atkins Breakfast Bars (The Cinnamon Bun is VERY good) and a Atkins Chocolate Shake (Tastes like yohoo) a total of 3 grams of carbs.
Lunch we did Tusker House's Chicken Salad, Toy Story Salad in MGM and Colony Salad at the Liberty Tree Tavern (you can ask for a different dressing as it has honey, but not a huge amount of carbs).
Dinner we did Beirgarten buffet (had the meats, and cabbages and salad), we also went offsite to Jungle Jims in the Crossroads for a Chicken Ceaser for DFiance and I had a French Onion Burger minus the bun/onion rings... they do lo-carb on anything they serve so instead of fries I got a good sized ceaser salad, burger with cheese on it, and a cup of FO soup, be sure to ask for no croton on the soup though... yummy!
We had no problem finding things to eat, plan ahead and check the menus for things you like. If you ask all the restraunts have the recipes/etc for each dish if you want to double check just ask. We also brought Atkins bars with us, and two Waist Watchers or Diet Rite sodas to curve the soda bug...lol.
I managed to lose 18 pounds between 1/4 and 1/21 and five of those days were spent in WDW...