hmmm......
I suggest testing- I can eat just about all taproot vegetables- radishes, carrots, rutabagas, beets, turnips, parsnips, daikon radish without a rise in my blood sugar. Although they may have a relatively high GI value, the glycemic load for these veggies is actually quite low- and glycemic load is a better indicator of how a standard portion of something actually affects blood sugars.
I usually cut them into matchsticks, toss with oil, roast them and then use them in stir fry or as a side dish. Most of these veggies have a good amount of fiber. Otherwise, I shred them and eat them raw in salads. Beets, in particular, are a rich source of magnesium- many diabetics are deficient in this important mineral.
I cannot eat tubers (i.e. potatoes), or kohlrabi (how bizarre is that?)!
sandy