"It’s a 1970s view to think it's only society and Calvin Klein" causing the problem, says Denise Heebink, a psychiatrist who treats eating disorders at New York Hospital’s eating disorders program. "A mental illness is complicated."

Anorexia nervosa, first described in medical accounts during the second half of the 19^th century, begins with a seemingly innocuous diet. Although the term literally means "loss of appetite due to nerves," anorexia nervosa is actually a self-induced starvation, where the dieter withers away to 85 percent or less of her expected weight. She may lose her period and grow unnatural body hair. Regardless of her actual weight, she is terrified of gaining even a pound.

After years of starving herself, Mysko felt compelled to eat. In college, she became bulimic.

"It was confusing. I didn’t have a sense of my true appetite," she says, of her inability to quit bingeing and purging.

Like Mysko, One- third of anorexics eventually develop bulimia. Some have a combination of both disorders.