>she ate lots of tinned beef smothered in potassium nitrate //
The injunction is surely not to eat foods available now that your grandmother wouldn't recognise as food rather than to eat what your grandmother actually ate.
Taken that way it's not saying the past diets were ideal but that the completely new foods are generally less healthy than the progressively developed foods.
You seem to have made an logically erroneous negation of the assertion being addressed.
The injunction is surely not to eat foods available now that your grandmother wouldn't recognise as food rather than to eat what your grandmother actually ate.
Taken that way it's not saying the past diets were ideal but that the completely new foods are generally less healthy than the progressively developed foods.
You seem to have made an logically erroneous negation of the assertion being addressed.