I have not read many books on supporting those with eating disorders, BUT, I have attached a link to a TEDx video we watched in my outpatient program that was beneficial for both myself and my parents. It talks a lot about the pathophysiology, what it is like for someone with an eating disorder, and just does an exceptional job of providing useful information in an engaging way.
[02/03/24]
I read "loving someone with an eating disorder" which significantly helped my early relationship!