I like coffee black but I do have blended egg yolks and MCT oil mixed with hot water everyday. For me, it prevents weight loss because I am generally not hungry enough to maintain weight based on hunger. This is an easy way to get fat calories when I am not hungry without feeling too full. I would tend to discourage drinking fat drinks for weight loss unless it was truly replacing a full meal.
Drinking fat just to raise ketones if your goal is fat loss seems counter intuitive. Correct me if I’m wrong?