Zuzanna Buchwald had been an athlete in Poland before staring a career in the US as a model, but she said her life soon spiralled out of control due to demands from her modelling agents.
"My agents told me to stop exercising and stop eating," she said, in an emotional essay and video for The Daily Dot.
"On my own and feeling alone in a foreign country, the pressure quickly developed into an eating disorder that I battled for almost four years," she wrote.
"Ironically, I was most admired by my agents and designers when I was at my unhealthiest and unhappiest. It was then that I worked the most.
"Staying a size 0–2 (UK dress size 4 to 6) throughout your career is the unspoken key to success in this industry."
"Young models learn about it the hard way: If an agency catches the smallest weight gain, you are measured, told to lose weight immediately, and reprimanded," she revealed.
"The skinnier you get, the better. The skinnier you are, the more desirable and valuable the industry sees you."
Now happy and healthy, Buchwald has vowed not to stay silent about the "exploitative and dangerous side" to the fashion industry any more.
She has called for it to "stop imposing this unhealthy, dangerous body-rigid ideal of a size zero and replace it with the image of health, happiness, and personality".