what has worked for me is - making intelligent choices and portion control.
EDUCATE yourself! This is the most important thing you can do.
The ADA website and message boards are your friends.
Get you a Calorie King book with all the carb counts in it, so you know what you're eating. When I first started out, I weighed and measured everything (for the first month) so I could see what was triggering my sugar spikes (In my case, white bread, white potatos, white rice, cereal, many fruits and pasta.) Then I avoided those things. Test, test, test.
Meat and vegetables and salads ARE available at counter service restaurants like the Sunshine food fair in the Land in EPCOT, Cosmic Rays in MK - it's just up to you to make the right choices for you. Table service restaurants are usually pretty easy.
Do I have a mickey bar occasionally? Yes, but only two bites and my husband finishes it. Amazingly, two bites is sufficient.
Good Luck.