I was going to ask the same question as bigbabyblues. Depending on what you consider healthy, there are many healthy things there. Almost every TS restaurant has some sort of fish on the menu and some sort of steamed vegetable. There are fruit stands in every single park. Almost all of the QS restaurants have some sort of salad, depends on you if you put dressing on them or not. I tend to eat light meals most of the time, some of my favorites:
Cobb Salad at HBD, while it probably wouldn't be considered "healthy" by most standards since it has bacon, blue cheese and dressing on it, it is lighter fare.
Chicken meal from Tangeriene Cafe in Morrocco, the meat is grilled, no rice and plenty of green things.
Small plates from Spice Road Tables, love me some grape leaves.
Caprese sandwich from Backlot Express.
When we eat at TS I always get either Chicken or Fish.