Most resorts have a make-your-own salad. I feel ya - even though I love stuffing myself beyond belief at Disney, there's days that I just need something fresh and not full of fat, sodium, or sugar.
I like to do a CYO salad and ask for olive and vinegar to avoid the crap in regular dressing, but many spots just have the packets of dressing.
Side note - Ale and Compass Market and the new spot in Dolphin are like an enhanced Starbucks. I got a cheese platter with dried fruit once, they have tons of salads, and even have this hardboiled egg and smoked salmon platter. It's a cool spot to get healthier options.