Diabetes has just about everything to do with blood sugar and how it interacts (or not interact) with your body from after ingestion.
Therefore, eating food with a low glycemic index (or even better, a low glycemic load) is a good start - but because everyone has different problems, restrictions, medications, etc., it is better to speak to your health care specialist.
For me, I can eat (moderately, of course):
* Bananas
* Corn
* Low GI bread
* Various meats
* Diet soft drinks
Things I avoid due to the adverse effect on MY blood sugar levels:
* Grapes (bummer - I love them)
* Mangoes
* Cane sugar
* Regular soft drinks
I can not handle the taste of artificial sweeteners in my coffee, so I take Xylitol for that, but if I am sure I am only going to have one or two cups of coffee for the day, I do tend to use normal sugar.
Please - this is NOT medical advice! It just works for me, and my readings, with proper management of my bolus, and using proper medications, work for me.