In the last year or 2 I've lost a pretty good amount of weight and even at WDW I am very conscious about what I eat. OK, I do splurge a bit but most of the time I do watch it.
At the sitdowns I tend to get a salad and an appetizer for dinner rather than ordering a whole dinner entree. If I do get an entree I usually order fish and any sauces or dressings for that matter I always ask for on the side. Any CS restaurants I just try to stay away from pizza or anything fried.
We now also tend to stay at the DVC resorts so that we have kitchen facilities available even in the studios. Most mornings we eat in our room to save time AND calories. I eat what I would eat at home. We'll now usually do 1 character breakfast the whole trip (and even in that day we'll do a light lunch). Never more than 1 buffet in a day. I even try to limit them for each trip. I always pack a small bag of nuts for a snack.
I also try to limit the alcohol and although many people feel like they walk miles and miles everyday (which you do, but it really isn't a cardio work-out) I try to fit in a run every other morning or a quick gym workout in the morning.
Since I've lost the weight we've gone to WDW several times and I've never returned with a weight gain unlike prior to my weightloss...

and I also still keep my food journal while I'm there. It just helps keep things in check and under conrol.
One of the best new restaurants that I can recommend though for those that are health conscious is The Wave. We enjoyed it very much our last visit. The arctic char was awesome! We plan to return there during our trip next month.
I just wanted to add that I see you're staying at AKL. They have a nice little workout gym there.
