None. This is a good question and frequently asked. The real question is how much, not what. In moderation and as part of a balanced, diabetic friendly (watching carbs) diet, any fruit is ok. There are many good resources by the mayo clinic, johns hopkins and others that can provide much more detail.
2 fruits/day. A diabetic should not eat more than 2fruits/d ex: 1//2 banana, 4 oz of juice, 2 prunes, small boll of fruits ex strawberries, blueberries, each equal to 1 fruit.
All ↑ Glycemic Index. Sugar control complex but is sugar, thus ??sugar intake, all forms. Study dietdoctor, taubes, attia, lustig. Best carbs: green&yellow above-ground vegetables, but no corn. No processed carbs-health claims mostly bogus. ? nat. Fat, moderate protein, extremely ?sugar/carbs best. For type ii, victoza (liraglutide) +/- symlin, adjusted up by user, not md, very helpful. Have seen hba1c ?from >11 to ?6.0 wks to mos.