Black coffee

I eat keto and without really trying end up doing 16/8 IF. (after dinner at 8pm I pretty much never eat until noon or 1pm the next day)​Each morning I have a few cups of coffee (not "bulletproof" with fat or cream...just black and no sugar of course)​Does this "break a fast" ? I'm hoping not and really want to know that it doesn't spike any insulin since from what I've read that is the main goal and result of doing IF.​Thanks in advance for your feedback or experience on this. via /r/intermittentfasting https://ift.tt/2NascRD https://ift.tt/eA8V8J