Whatever works for you… Sadly, I strongly prefer my coffee with cream (I can drink it black but it’s not nearly as enjoyable) and 5ml cream in my coffee is definitely not fast to me (I don’t care if it interferes with autophagy or not, it has calories, it’s not a real, clean, perfect fast. if I fast, I prefer really doing it but it’s fine to do differently, of course especially if fat-loss is the goal but not only then. it’s up to the one in question) - so I try not drinking coffee in the morning (or ever). With little results this far… Even if I keep my coffee, I prefer having it closer to my mealtime. Almost all my life I only drank coffee after noon anyway, it’s time to go back to that.
Fat-loss wise… It’s quite individual and coffee with cream is only a single factor, amounts matter too… Some people would lose all results just having cream for some reason… I don’t lose fat on any woe and style anyway (I hope it started to change very lately, it seems so) so it doesn’t matter to me… Okay, I am always hopeful so yep, it interferes with my decisions
Extra cream is clearly bad for my fat-loss plans, it adds calories (not even very little as 5ml is for 1-2 coffee and I easily have many. I try not to) while having zero effect on my satiation - or if I have more cream, it just makes me hungrier, I can’t have tiny meals (a few kcals often stay under the radar but any more and it causes… not problems but a full-blown meal for sure).
But it’s mostly neutral. Definitely not good except it makes my coffee tastier but a good brand and more water solves my black coffee problems anyway. Or tea or water. I don’t need coffee, I am just too used to it and I don’t want that. So of course I skip coffee if I can. Oh coffee with cream brings my mind closer to eating too, I already think about food all the time (I don’t want to eat, just think about it. nice topic. and I cook and bake a lot for the family), no need to make it worse
Fasting is cleaner, simpler, better to me.
So it’s complex and individual. Many people says coffee with cream helps them with fasting. I fast only when I am satiated or just borderline, not really hungry so I don’t need anything and nothing helps when hungry, only lots of protein and fat… With my smallish energy need and kind of big meals I can’t afford extra fats… But many do.
Now I do OMAD (with some extra bites sometimes. and cream in my coffee when I can’t resist… sigh), my meal is somewhere after 3-4pm. My main goal is not overeating and it happens with or without cream but I need to be careful with the amount (it’s easy, I find my 2-5ml cream perfect for a cup of coffee. but it must be the fattiest kind I can buy :)).
I don’t have cream every week. I noticed very little difference except I do proper fast when I don’t have any. And much lactose feels not so good but I never have much anymore.
So if you put a ton of cream into your coffee, there is a much bigger chance it affects various things negatively. A little bit is mostly harmless.
Sorry, I should have been more concise as usual.