Actually, rather than being obsessed with what sugars are or are not good for a diabetic the most important food compound to be aware of is carbohydrates. Sugars are carbohydrates, as are starches (rice, potatoes, pastas, breads, etc.) The body converts carbohydrates into sugars which in turn raises blood sugar levels.
The average diabetic woman should try to consume no more than 30 to 45 grams of carbohydrate per meal. The average diabetic man should try to consume no more than 45 to 60 grams per meal.
Thus if you read the ingredients of any food label you should look at the total carbohydrate content in grams which are in a serving. The labels will first specify total carbohydrates and right underneath list the total carbs from fiber. Interestingly, while fibers are also carbohydrates, they do not raise blood sugar so they can be subtracted from the total carbohydrates in a serving.
If a diabetic concentrates in carbohydrate awareness rather than just sugar awareness they will do much better in controlling their blood sugar levels in the long run.
The degree to which certain foods increase the blood sugar level is called the glycemic response. Diabetics who regularly check their blood sugar levels with a glucometer will be able to assess the degree to which consuming certain foods will raise their blood sugars. Here is a site that will gives a very cursory look at glycemic reponse of certain foods:
Education and awareness are the most important tools in diabetes control along with weight control, regular exercise, a healthy diet, regular blood glucose monitoring and proper medication.