As you can see my my signature, we've done a good bit of healthy eating at WDW, while trying to lose our combined 160 pounds. What it involved was austerity and determination.
Salads, however, and especially entree salads, are notoriously poor ways of trying to lose weight. For example, McDonald's Crispy Bacon Ranch Salad has
more fat and calories and just as much cholesterol as a
Big Mac.

As a matter of fact, all of the salads at McDonald's, Burger King, Wendy's or Taco Bell fail at least three of five standard health metrics, and all except two (both at Wendy's) fail at least four of five metrics. The salads on the menus at WDW are wonderful meals. However, as typically prepared, they are unlikely to be healthy choices, just as the salads at the fast-food restaurants mentioned above aren't healthy choices.
Our favorite salad at WDW is the Hollywood Brown Derby's Cobb Salad. However, the
original recipe had about 630 calories and 44 grams of fat, and we know everything has been "super-sized" since then!
While we were losing weight (it took nearly 18 months), we focused on
seafood. HMR taught us that most white fish has about 25% of the calories of the same amount of beef; about 50% of the calories of the same amount of chicken. However, we had to be vigilant to get the chefs to prepare the fish dry, instead of drowning it in oil, and of course, we never ate fried fish. (Even the "good" oil has lots and lots of calories.) Oven-fried or battered and backed are just about as bad. HMR's rule of thumb is that any of these standard preparation methods for fish end up multiplying the calories by a factor of four.
We also would eat vegetarian meals. Vegetables have even fewer calories than fish (though most of the vegetarian choices typically available at restaurants have very little protein, which is an essential nutrient to prepare your body for weight-loss maintenance, so just going veggie isn't a panecea). With pure veggie dishes, we were a bit more laid back about the amount of oil, but still wouldn't accept anything with too much oil. This meant that the standard vegetarian dishes on the menu were not acceptable. We had to negotiate something special with the chef in each case. (Spoodles was especially accommodating.)
Counter-service restaurants were generally off-limits. What I think is interesting is that one of my mainstays of the few counter-service meals we did eat while we were losing weight -- baked potato with mustard
(I thought of the baked potato as an oddly shaped knish!) -- doesn't seem to be as available any more. A quick Google search of the menus on Deb Wills' website didn't yield any counter-service restaurants still serving them.
I'm sure there are other alternatives now. There is a lot more fruit available now.
I suspect we could start a thread on the
W.I.S.H. Board that'll yield up a lot of great options. Sorry to say, though, that the idea of trying to eat healthy be just eating salads is not going to be a constructive approach.