Sorry for the late response, but I have some interesting information for you regarding this. From what I have gathered from meme pages and watchdogs on social media(usually owned and run by former high fashion models or runway insiders), in the 'Big Four' fashion weeks taking place in Paris, Milan, London and New York, it is a very common practice to hire clinically underweight models. It's because of a common belief within high end fashion houses that the model must be as skinny and tall as possible to fit an attractive 'aesthetic' for their esteemed brand. I went on a search for fashion shows once to look for a particular ensemble and I was shocked to see the bare torso of a woman at a show who looked just around 10-20lbs away from looking like Eugenia Cooney. I don't think this is a problem especially if a model was already underweight in the first place(because not everyone who is underweight has an eating disorder of course), but I disagree with certain practices which could be considered exploitative such as bad nutritional advice and an inadequate timeframe given to models who are over the desired weight to prepare for the shows and photoshoots. Moreover, the models(who can sometimes be underaged) are not educated about how to weight cycle skillfully to ensure your diet plan remains sustainable over time(like the kind of advice that experienced actors like Christian Bale or bodybuilders get). Of course, there is also the argument that the models who are unhappy with the timeframe and conditions to just reject an offer from a fashion house and go into regular retail modelling. There's also a sketchy practice of certain model agencies who pressure their healthy BMI models to deliberately binge and overeat so they can become plus sized models(barely there smallfat ones) because 'they're too fat for runway and not enough for commercial'. In addition, for the majority of couture fashion houses(excluding woke ones like Fenty and Chromat), there is surprisingly little to no vanity sizing that has occurred within them. Everything is pretty much true to size, and what makes a 'plus' or 'curve' model could be someone of a perfectly healthy weight(albeit in the 20-23 range of the BMI. This is what I think confuses a lot of people, because they might think that the high fashion world is in the same dimension as pleb retail(fast fashion, bespoke, etc).