[kingkongrevenge]

Japanese lifespan and health have improved as fat consumption has risen almost geometrically. The healthiest Japanese are the Okinawans, with the highest fat consumption.

I can't comment on why Japanese have relatively low rates of obesity for the industrialized world with a starchy diet. But the pattern does generally hold true.

> The current American diet is actually unusually high in protein and fat by historical (i.e. pre-WWII) standards.

This is simply wrong with regard to fat. I don't know about the exact change in protein intake, but people eat much less fat and oil now than historically. You can't even get things like beef kidney, suet, or lard anymore at American grocery stores.