I didn't say rotting things were good (let's put aside the question of fermented foods for a bit). Our ancestors were repulsed by things, that indicates strongly that they are bad.

But I think you are missing my point. I am saying that we are all dumb as rocks. We barely evolved any intelligence at all, and far too often we think we know things and we act on that supposed knowledge to our detriment. And so when someone says "It's very obvious which things were good and which weren't" my point is that it absolutely is not obvious:

* It was obvious that the sun caused skin cancer and we should lather up. It was not obvious that the sun's vitamin D production cut heart disease risk so far that sunscreen wearing caused more deaths.

* It was obvious that saturated fat caused heart disease, and so margarine would be healthier. It was not obvious that trans fats cause huge problems to human bodies that did not evolve to handle huge loads of trans fats.

* It was obvious that intestinal worms were bad (duh!) until we learned that our bodies expect them. I have personal experience on this one.

Nothing is obvious. We live in a hyper-complex system.

And so we have to trust that we evolved to work against a certain kind of environment and we should mimic that environment as much as possible to avoid risk, because any sort of changes to that environment are very likely to be in the bad direction (some could be good, but always bet the other way) even if they seem obviously in the good direction.

I am constantly amazed at how fine tuned life is towards it's environment, and how even small changes in the environment cause species extinctions. And yet us humans are tweaking our own environment in massive ways, and then suprised that we develop allergies, autoimmune diseases, metabolic syndrome. The causes are obvious. The solutions are hard to put into practice, but we know what they are. Tribal people don't have diabetes, autoimmune diseases, metabolic syndrome, allergies, etc.

Saying "fasting also comes with innumerable desteuctive [sic] effects the worst of which is an increase in cortisol" presumes we know far more than we actually know about fasting, about cortisol, about why your body is producing it, etc. I can point you to many studies showing how fasting is very healthy, despite the alleged spike in cortisol, but that's not the argument I'm trying to make here. The argument I'm trying to make is that humanity is a lot dumber than we pretend to be, to the extent that simple heuristics like "do what your ancestors did" do better than trusting the current science does.

It turns out our ancetors didn't have fruit all year round... we probably shoudn't either. It turns out they sometimes went days without eating, because they couldn't find any more food. Turns out that is good for us too. Our ancestors almost all ate meat - we should too. Our ancestors didn't use fluoride in their water or toothpaste - we shouldn't either. Fluoride hardens teeth with calcium, why shoudln't it then also harden arteries with calcium? that seems obvious to me but it is the opposite of what we are told. Flouride occurs naturally in some water supplies, but if your ancestors didn't come from there, you aren't attuned to it. Our ancestors didn't live indoors. Our ancestors sat around fires at night. Our ancestors squatted, they didn't sit in chairs. Lots of things to mimic that, if you try it, you will find you start to feel a lot healthier.

Evolutionary biology and game theory -- it is an entire way of thinking. It changes everything.