Tuberculosis—known at the time as consumption, phthisis, hectic fever, and graveyard cough—was an epidemic that affected all classes and genders without prejudice. Today, an estimated 1.9 billion people are infected with it, and it causes about two million deaths each year. At the time, it was mainly associated with respectable women (although there are no few depictions of sex workers dying of it*) and thought to be triggered by mental exertion or too much dancing.** Attractive women were viewed as more susceptible to it because tuberculosis enhanced their best features. It was noted to cause pale skin, silky hair, weight loss, and a feverish tinge to the face (along with less desirable symptoms including weakness, coughing up blood, GI upset, and organ failure), and it was treated with little to no effect with bleeding, diet, red wine, and opium.
Women with consumption were regularly praised for the ethereal loveliness that came from being exceptionally thin and nearly transparent.
Source : https://dirtysexyhistory.com/2018/05/16/drop-dead-gorgeous-19th-century-beauty-tips-for-the-aspiring-consumptive/Corsets could be made to narrow the waist and encourage a stooped posture, and necklines were designed to show off prominent collar bones.
Have a Daughter? Guarantee her Future Beauty With Malnutrition!
https://dirtysexyhistory.com/2016/09/08/nineteenth-century-skin-care-ten-tips-from-the-ugly-girl-papers/“Some mothers are so anxious to secure this grace for their daughters that they are kept on the strictest diet from childhood. The most dazzling Parian could not be more beautiful that the cheek of a child I once saw who was kept on oat-meal porridge for this effect. At a boarding-school, I remember, a fashionable mother gave strict injunctions that her daughter should touch nothing but brown bread and syrup. This was hard fare; but the carmine lips and magnolia brow of the young lady were the envy of her schoolmates, who, however, were not courageous enough to attempt such a regime for themselves.”