But how did people survive their craving, they must have all been completely on the verge of insanity right?

Are all these lean and healthy people from archive videos actually suffering and in distress? Poor souls...

> Are all these lean and healthy people

Vast numbers of these 'lean and healthy people' were suffering from serious nutritional deficiencies. Pellagra (generally caused by eating nothing but corn) wasn't really knocked out until around WWII, for example.

“Eating disorders didn’t exist one century ago” is indeed some take.