I can do this with my own self-produced insulin. If you wait until things have settled down, an hour or two after eating, you probably won't get such a huge drop. I use it as a party trick when eating out and I can't avoid too many carbs, sneak out and yomp round the village immediately after eating. Can be a bit hard to control the effect though, once I had to put Real Sugar in my coffee due to overdoing it a bit.
