That’s what I do sometimes. I make mine a pea protein shake rather than whey. I have one with lots of vitamins and minerals. DeLauer says break your fast with lean protein or a pea protein shake. He explains that the body is sensitive because you haven’t been eating so you want the first thing in your body to be protein along with some other mineral to kickstart your metabolism again and absolutely never carbs and fats!!
Check him out He has a video specific to women and IF. In it he addresses what you should eat to break a fast and more. I am SO SORRY. I DONT KNOW WHY I JUST assumed you were female. If you are Great if you’re not then there’s also a video on regular IF