From the link Allie posted:
Over four days of continuous fasting, basal metabolism does not drop. Instead, it increased by 12%. Neither did exercise capacity, as measured by the VO2, decrease, but is instead maintained. In another study, twenty-two days of alternate daily fasting also does not result in any decrease in RMR. . . .
. . . What is the difference? Obesity is a hormonal, not a caloric imbalance. . . . The reduction of insulin and insulin resistance in intermittent fasting plays a key role.
There’s the answer you are looking for, I believe: The reduction in insulin resistance from the lowered insulin and the consequent opportunities given to the mitochondria to heal, especially when fasting is coupled with exercise, as it would have been for our ancestors “in the wild.”
The fat in the cream you mention triggers very little insulin response, but it does trigger some. A minimal quantity of insulin in the blood is required for survival, after all.
The effect of coffee is up for debate. I have read on this forum authoritative statements that (a) coffee stimulates ketogenesis, and that (b) coffee halts ketogenesis. I don’t know why either should be true, and I also don’t know why it is always stated in terms of “coffee” and not “caffeine,” and why tea is never mentioned. Presumably caffeine has no effect, and it is some other ingredient of the coffee bean that is the problem.
I would raise a question about your statement that you saw “zero results.” What precisely do you mean, here? If you are saying that the needle of your scale failed to move, that is one thing, but if you say your dexa scans before and after your fasting days failed to show recomposition of your body mass, that is quite another. It is always worth bearing in mind that we often speak of losing “weight” when we are really talking about losing fat. It doesn’t seem productive to me to get the scale needle to move at the price of reducing muscle weight and bone density. I suspect that the concept of “weight” loss and the idea of “a calorie is a calorie” have combined to lead many a woman into muscle weakness and osteoporosis, clearly a detrimental position to be in as one ages.
Lastly, I would also ask about what might have changed in your metabolic markers from fasting. Many people adopt a ketogenic diet for “weight” loss, but the loss in body fat is secondary to the metabolic healing that takes place. After all, the obesity is a consequence of the metabolic disorder in the first place.