It's a little different for everybody. Most can handle a serving of blueberries, or blackberries, or raspberries.
Most can handle a serving of strawberries, a serving of apple or a serving of pear.
Personally, I cannot handle grapes, or sweet cherries, or mango, or banana.
I can handle some watermelon. But no cantalope or honeydew. I can handle a serving of peach, or nectarine, or plum, or apricot.
You might have to eat to your meter. Watching how large the 2 hour number goes.
Anything 2 hour above 7.8(140 usa) is too high.
Anything below 7.8(140 usa) is Great.