Then why are we taller, stronger, healther and living longer and living better than any time in history? The folks in Lesotho, Africa eat a very pc diet (little meat or refined or gm fruits and veg., lots of beans, grains, etc.)and their average life span is 48.7 and falling. The Siberian aborigines with their very high fat diet are not exactly famous for their quality (and lenght) of life.
Because of fast food, hehe. Actually mostly from better medical care and less manual work lifestyles, but also from better nutrition. A Chinese boy that grows up on an Iowa farm grows up huge in comparison to Chinese natives. Long life though is not the product of a low-fat high-carb diet, it is in spite of it. The body has amazing powers to process whatever we feed it into what it really needs. However there are limits to what our tiny pancreas and single stomach can do with a high carb diet. We took a different evolutionary path than the cows.