I mean, this is not scientific and all, but for the sake of the argument: your argument is not contrary to the grandparent's. I.e. a keto diet may be beneficial

I mean, this is not scientific and all, but for the sake of the argument: your argument is not contrary to the grandparent's. I.e. a keto diet may be beneficial for a hunter-gatherer who only lives 30 years while bad for someone who lives well beyond that (because evolution never got to sort out that case due to injuries, disease, etc.).