The mentioned "Nutrition and Physical Degeneration" by Dr. Weston Price is wonderful - a catalog of a globe-spanning research expedition

Moreover, Dr. Price's book inadvertently explains (to my mind) the Holocaust, which was not a sudden shift but rather the culmination of a long social panic (racial degeneration) over the imminent and ongoing destruction of society, much like climate change today.

The degeneration panic also explains why since WW2, ever-worsening chronic health conditions have been accepted as normal facts of life. We already had the panic, solved part of it by supplementing processed foods with some of the nutrients that had been removed, and tried to solve the rest with racial psuedoscience which made the whole issue too horrible to contemplate