Since we don’t do low-carb, I cannot speak from experience. But my understanding is that Bernstein dieters are, in general keeping their insulin doses very low. Possibly someone he follows Bernstein will correct me? @walkingthedragon88 had a really interesting thread about her experience: Sharing my story
It only takes a couple of days before your body switches to a different sensitivity though.
I do think, though, that Bernstein is not for everyone (not for us right now for instance).