I can only say what my experience has been with low blood sugar. When I eat sugary/starchy carbs and not enough protein I have the yo-yo effect spikes up, (but not in the diabetic range...at least that I'm aware of) then crashes. But when I eat only small amounts of those (or none) carbs and eat "good" carbs and protein, no problems at all. In the "good" category for me are low glycemic fruits (mainly berries), whole grains, green veggies, small baked sweet potatoes, squash (summer and winter), legumes, etc. I can eat the "bad" carbs, but in small quantities and along with better choices.
The trouble was before banding "small quantity" was much bigger.

It seems to be a ratio thing to keep my blood sugar more even.