I'm trying to eat healthier, and found some great options on my past couple of trips. There is a delicious-sounding veggie sandwich at the Plaza (but I haven't tried it yet). The Plaza also has very yummy no-sugar-added butter pecan ice cream, but unfortunately, it was not low-fat. (A low-fat chocolate vanilla swirl is also available there, but it is made with sugar.)
I had a terrific tomato-mozzarella sandwich for lunch at Yacht Club Galley last month. Le Cellier also has a tomato-mozzarella-basil stack with balsamic vinegar that makes a great appetizer. (I hope tomato and mozzarella are OK'ed by your nutritionist because these are both SO good!)
Beaches and Cream (and other locations, too, I'm sure) has a pretty decent veggie burger. And they were more than happy to substitute fresh fruit (melons and grapes) when I requested it be served without fries. Bagged baby carrots are also available at some CS restaurants as a french fry substitute.
My experience with Disney's chicken Caesar salad has been disappointing, however -- at multiple locations, they really loaded up on the dressing and croutons, and it was never the light meal I'd hoped for. If I ever order again, I will have to remember to speak up about my preference for just a small amount of dressing.
If you're on the
DDP, you'll need to be extra vigilant. It's a ton of food! Be sure to ask if you "have" to have the listed dessert at CS restaurants. A DISer had posted her experience last year that she was allowed to have a bottled water for "dessert" at some of the CS locations. I tried it and was successful in October at CHH, but as with everything DDP-related, YMMV and only Disney can tell you for sure if this is OK.