I would love it if there was a website that had the nutritional info but with how lax Disney is in maintaining the rest of their sites I doubt it would be up to date.
What are you looking for? If you are just trying to eat a little healthier down there I have found it is pretty easy to eat healthy at Disney with just a little effort. Some of the buffets, especially Tusker House and Boma, have a lot of healthy options. Also remember some simple alterations can make a meal much healthier. Ask for meals that come with sauces, especially heavy or cram based sauces, to go either light on the sauce or remove it entirely. I also always ask if anything cream or butter based is used in preparing the dish and ask for it without.
If you are looking for more specific choices I recommend checking the menu sections of wdwinfo and allears.