1st, I agree with others have said regarding going just black coffee, tea, et al during your fasting hours.
Having said that, may I suggest that during the first week or so, you reduce the amount of butter to adjust your taste buds? And follow up your coffee/butter combo with a glass of water. I’ve found this to be helpful with my evening wine…and I’ve reduced how much wine I consume.
I’m also a newbie and have been doing more of a “dirty fast”. I need coffee in the mornings but I just can’t get with black coffee. I’m doing IF for weight loss and figured a splash of zero sugar creamer isn’t gonna make me gain weight if my actual eating is during my window and my meals have cleaned up. But ONLY A SPLASH, enough to make the coffee drinkable for me. I’ve even just added a pack of stevia and no creamer.
I started with coffee or tea with a little heavy cream and stevia. Yes, the heavy cream has up to 50 calories, but I was told that if it’s ONLY fat ( no protein, no carbs), it shouldn’t raise glucose, therefore not breaking your fast. Did my weight loss show if it mattered? Nope. I still lost and I didn’t feel deprived, either. Do what YOU feel you need to do. If you don’t feel like you’re losing what you’d like, then stop heavy cream or adding anything and see if it makes a difference.