Well, Germany is not technically a city ;-) ...

However, if you are there during May/June, asparagus (the white kind) should be in season which is absolutely delish -- I really miss it here), and as far as I know, both super lowfat and lowcarb. Prague may be a bit of a challenge foodwise, though I hope you'll be able to have some of their beer (it is great, but I don't know whether you can have it as a diabetic?).

I still think you'll be able to find plenty of low carb & low fat food in all countries you are travelling. Most European cities have markets on the weekend or during the week where you can buy anything from fresh produce & meat to fish and fruit. I wouldn't worry, and enjoy the experience. You will miss it once you're back in strip mall country U.S.A.