Are pineapple and grapefruit good to eat for diabetics or there are too much sugar in them?

Not too much.: Part of a healthy diet. No one ever said you cannot eat sugar. All we ask is that you eat reasonably. There are 32 g of sugars and 160 calories in 1 cup of pj. Suspect much less in the grapefruit. Just eat sensibly.

SUGAR: A lot of sugar in those 2. You can drink them but stay within the daily carb range recommended by your doc or dietician. On an unrelated note, there are so many drugs that grapefruit juice interferes with, I have gotten in the habit of telling my patients that they should avoid it, especially if on multiple medications.