We are frequent day guests, and I'm actively counting calories, so I am always on the hunt for healthy options, too. It is hard since they don't provide nutritional information.
- Satuli is a good option; I like the kale base and the chicken is good. I get the sauce on the side and barely use any of it.
- Columbia Harbor House has salmon with rice and green beans that isn't bad. I've doubled the green beans before and they were accommodating.
- Skipper's Canteen (though not a quick service) has a veggie/tofu curry that I thought was pretty darn good. It's dairy free and rice is on the side.
- Tangierine Cafe has some great options - I like their vegetable platter and their chicken shawarma.
- At AK, they grill fresh corn on the cob back in Africa near the safari and you can ask for no butter. Corn on the cob isn't the healthiest vegetable out there but for a theme park, it's not bad and they will sprinkle it with curry powder so it's really tasty and helps with my salty craving.
- Sushi rolls at the QS in Japan are not bad as long as you don't get the tasty, I mean, fried ones

- For breakfast, I like the egg white frittata at The Wave - it's loaded with spinach, mushrooms, poblano, and cheese but I have them leave out the cheese. We like to eat breakfast on site a lot and that's just about the only good option I've found.
- Kid's meals are a good option, esp the Disney check meals.
- I have had success subbing fries with a fruit side at QS. Sometimes it's the fruit that normally comes with a kids meal but I don't care.
Be careful with the salads - some of them are killers with the cheese, croutons, etc + many come pre-dressed. Ask for it deconstructed

I will warn you not to order the salad at Flame Tree; it was the grossest thing I've ever been served at WDW and I was mad at myself for wasting the money on it.