Now that I stopped trying to keep calories down and eat as much fat as I can handle (about 4/5 of my calories come from fat), I lost 30 lbs from my maximum, feel much better (in addition to having more favorable biomarkers), have significantly improved cognition, and almost never feel miserable because I'm hungry. This is precisely the opposite of the advice I received from virtually all the diet authorities I had encountered like my high school health textbook and doctors.

At what point do we start considering the hypothesis that different people have different things that work for them, and that a diet that is healthy for one person may be terrible or even life-threatening for another person?

So much focus is given on "Dietary advice X is good!" / "Dietary Advice Y is bad!", instead of asking how dietary behavior X interacts with metabolism Y?

I wonder if there's a market for a company that uses blood samples to examine various metabolic markers and meal logs to examine dietary behavior, and then correlate them over time with health markers and use that to craft a personal diet plan?