Plain yogurt is a good choice, as the bacteria convert much of the milk sugar into lactic acid, which doesn't raise blood glucose (that's what makes it tart). But if you eat fruited yogurt, especially if it's sweetened, it's not a good choice.

Your best bet is to buy plain yogurt and add your own flavorings. Berries raise blood sugar less than some other fruits. In general, although fruits are supposed to be "healthy," they're loaded with sugar and aren't good for people with diabetes. You can use fruit flavorings too.

The best way to determine what works for you is to test your blood sugar 1 and 2 hours after eating the yogurt you like and then decide if it's worth it.