Elizabeth Woolley reviews most of them at her About.com column on type 2 diabetes. I don’t endorse everything there; just thought you might be interested.
I still see doctors at the hospital order “ADA diet” (American Diabetes Association) for their patients with diabetes.
There is no ADA diet.
-Steve
Paleo Diabetic 
Thanks for this link, Steve. Glad that the Mediterranean diet and Paleo diet are discussed. Diets based on the exchange system are on the way out, although still used at most hospitals. At our facility, physicians order the “ADA diet” as well, which translates to our “Consistent Carbohydrate” diet: 240-275 grams of carbs per day. Pretty much the same as our “Regular” diet except they receive sugar substitute instead of sugar packets.
Wow, Franziska. That’s a lot of carbs for a diabetic!
-Steve