Yeah, it's mentioned that Angela and Heather started a new trend of beauty from the new type of corset they made. It didn't say that they invented the corset, so that meant that the corset was already a thing in this world. It was only Heather's version that caused other women to go crazy to try to be very slim because they wanted to be as beautiful as Angela.
So the people saying that this is villainizing corset is technically not true. What caused the death of hunger was not from corset in general. It was from Heather's corset and Angela's influence on fashion.
it's probably tight-lacing --the victorian's used to make their waists slimmer. ppl in the past wore corsets since it was an undergarment and support
for the front and back. it's like modern bras.
I'm this chapter they mentioned that they're using corsets but not to the extent where they need to diet but that in the past the new girl Heather develop a new type of corset where it shows more slimmer waist. This become trend in the past so many girls go for a diet but some died because of hunger.