Report: glycemic index plays an important role while deciding which fruit is safe for diabetics and which is not. The fruits that have a glycemic index below 40 are safe for a diabetic to consume. These will not cause a sudden spike in blood sugar. These include berries like strawberries and blackberries and pears and oranges and apples. The fruits that should not be consumed unless in low quantities are watermelons and any kinds of melons. Grapes and bananas are also not to be taken in large quantities.