09/26/2012 at 05:40 PM EDT
TLC's Stacy London is known for her trademark silver streak of hair and her frank-but-funny approach to style while giving makeovers on What Not to Wear.
But in the newest issue of PEOPLE, on newsstands Friday, the reality star reveals a shocking and much more vulnerable side to her personality: London, 43, admits to suffering from both anorexia and compulsive overeating in the past.
The TV makeover maven battled anorexia in her early 20s because, "I felt like I'd never had a serious boyfriend and I really wanted to be attractive," she told PEOPLE. Her dieting soon spiraled out of control, leaving the 5'7" star a skeletal 90 lbs.
After a brief hospitalization, London began to eat again, only to see the pendulum swing in the other direction as she began binge eating to mask her self-doubt. Within a year, she doubled her weight to 180 lbs.
London decided to dive into her emotional and physical struggles with her body in her new book The Truth About Style, out Oct. 2, in the hope that her journey will help others facing similar body-image battles.
"When you can talk about something and shine light on it, you're obliterating shame," says London. "And that to me was always the really hard part – to feel so filled with shame and having no recourse to thinking it could get better."
Nowadays London realizes "my value doesn't simply come from [being thin]. It comes from me and solely from me," she says. "It took me a long time to recognize that."