A former top editor of Vogue Australia magazine has written a book exposing what she says are some of the secrets of the modeling world, including how some models at tissue paper and starved themselves for days on end in order to maintain their slender figures.

Kirstie Clements, whose book, "The Vogue Factor," is an account of her time in the industry, was fired from her editor-in-chief job at Vogue Australia in May of 2012.

Speaking Wednesday to "Entertainment Tonight" about her book and the industry, Clements recalled one season when she said models were particularly thin.

"I was having dinner with a New York agent who said to me that a few of the girls had resorted to eating tissues," she said. "I'd never heard of such a thing. I said 'Oh, what did that do?' And, apparently, they swelled in your stomach and made you feel full, and I definitely heard that some girls were unwell and starving themselves and were on drips. Over time, I did hear that."

She also told "ET" that already-slender models who aspired to becoming catwalk models in Paris were often expected to lose " a great deal of weight" so they could fit into the sample sizes.

Runway models were typically thinner than the models who would appear in the magazine, Clements added.

Cynthia Bailey, a model, star of Bravo's "Real Housewives of Atlanta" and CEO of the Bailey Agency in Atlanta, says she has seen models go through "real extremes" to avoid gaining weight but is surprised to see the measures made so public.

"I am a little surprised that a Vogue editor is speaking out about it because usually these are things that we just know about but we never talk about," Bailey said.

Clements stressed that not every model lost weight in an unhealthy way, but said models faced tremendous pressure from within the industry, and some of them engaged in "dangerous" diets in order to achieve the expected look.

She added that she "felt complicit" in the problem, and said she believed the fashion industry was complicit as well.

Clements told "ET" that her book was not a "bitter" expose, but rather told the truth about what happens in the fashion publishing world.

"It's honest and honesty. It's not bitterness," she said.

The newest editor-in-chief of Vogue Australia, Edwina McCann, told ABC News that she can only speak for the magazine as it stands today.

"We are vocal ambassadors for the message of healthy body images," she said.