On a more serious, less cynical note...
I don't know your motivation behind the low fat diet - it could be a health issue. If it is, then please ignore these next few paragraphs.
Strictly speaking from a diet standpoint (if you're trying to lose weight...) don't worry about the "low fat" fad. I'm not a dietician or a personal trainer or anything like that. I'm a copywriter - I sit at a desk all day. BUT, I have lost 90 pounds in my lifetime. I was 247 pounds and as I write this, I hover between 157 and 158. Through it all, it's been about calories in vs. calories out. Are you burning 2,000 calories a day? If you eat 2,100 calories a day, you'll gain weight. If you eat 1,900 calories a day, you'll lose weight.
I'm not gonna take over the DIS and turn it into a diet forum, but any time I've been to Disney, I've seen an uptick in weight when I get home, and then it comes off over the course of the next week or so. You're going to gain a lot of water weight in Disney - there's a lot of salt in that food. BUT - the gain is normally temporary. You're walking at least 8 miles a day in Disney. That's a lot when you really think about it!
Disney has done a great job in offering a variety of food for those with diet restrictions. It's no longer just "I'm diabetic, I need a sugar-free dessert" and they bring you some generic scoop of ice cream. THey now offer a lot of gluten-free options, plenty of sugar-free and no-sugar-added desserts and plenty of healthy options. There's salads and sandwiches at Boardwalk Bakery, there's many Create-Your-Own salads (Landscape of Flavors and other food courts) and plenty of healthy desserts and snacks (from fresh fruit to sugar-free versions of your favorite dessert.)
I eat A LOT at Disney. I diet going into my trip and purposely lose around 5 pounds before as a "buffer." One day I actually had breakfast at Tusker, a full-blown QS lunch with a dessert, popcorn, a CS dinner with a dessert, a Dole Whip and shared a cookie. I have a very, very large appetite and even bigger sweet tooth.
Now, I will say this - I think there's a lot of calories in Disney's food. I think there's far more than you'd expect. You can look online and compare it to comparable foods (for example, if you're eating a lobster roll, check out calories for a generic lobster roll.) I would then take that calorie amount and add 10%. So if a generic lobster roll is 600 calories, I'd say a Disney version is between 660 and 700.
Keep your fat at around 40-65 grams, eat your weight in protein and it's up to you for carbs. If you want some pasta, eat it - you're on vacation. Honestly - it comes down to calories in vs. calories out.. and - you're on vacation!
**EDIT - Just read your reply that it's a health issue. You can totally talk to the chefs and let them know. Best of luck!