From here:
SOFIA: But Sabrina started digging, looking at 19th-century magazines like Harper’s Bazaar, and what she found was troubling; articles warning American women – well, middle-class and upper-class white women – they needed to watch what they eat.
STRINGS: And they were unapologetic in stating that this was the proper form for Anglo-Saxon Protestant women. And so it was important that women ate as little as was necessary in order to show their Christian nature and also their racial superiority.