NEW YORK — You know it's going to be painful when the virtuoso of fashion wisdom dismisses your black-and-silver peep-toes as "sensible heels you wear with a cocktail dress when you're getting old and you don't want to wear heels anymore."

"You had a lot of opportunity here," Stacy London pronounces.

It was not quite like having your entire wardrobe gleefully dumped in the trash a la London and co-host Clinton Kelly on their long-running TLC makeover show, What Not to Wear. But after the style savant's assessment — "Style is the quickest shorthand to who you are," London writes in her new book, The Truth About Style (Viking, $32.95) — it's hard not to question a lifetime of sartorial choices.

And yet London, 43, is somehow on your side as she rips you apart. She understands the psychic roadblocks manifested by an ill-fitting outfit. She says there's more to bad dressing than bad taste: Women, she argues, cloak their emotional issues in their clothing.

"My whole life I've had a love-hate relationship with style, and my body, and myself and self-consciousness," she says. "And I have not met very many women who haven't."

The book transposes the show's makeover format to the page. It features nine women in fashion ruts. With empathy, a little therapy and an eye for what's flattering, London diagnoses their fashion problems and proposes common-sense solutions. As she does on the show, London shifts the conversation from the runway to real life, focusing on practicalities such as helping the working woman "who just needs a great pair of jeans."

Makeovers notwithstanding, a more apt title for the book might be The Truth About Stacy London. It turns out that the stylist who inspires godlike reverence from her fans is just like them: highly imperfect. London writes about a traumatic bout with psoriasis that started at age 4 and left painful scars on her arms, torso and thighs, and dramatic weight fluctuations caused by anorexia and compulsive overeating.

"After 10 years of being the expert, I wanted to make myself a little bit more dimensional," she says. "I started to feel a little bit boxed in by the idea that people will tweet me and Facebook me and say, 'You're so pretty and you have such confidence.' Well, I don't feel that way."

Turning the tables on herself wasn't so easy.

"Dredging all that stuff up," she says, "it brought back a lot of pain that I haven't looked at in a long time. To be honest, I wish I had been in therapy while I was writing the book."

The steroid that eventually cleared up her debilitating skin disorder left painful cracks and fissures. The emotional scars resurfaced at Vassar, where a diet spun out of control. Surviving on sugar-free butterscotch pudding, she hit 90 pounds. After graduation, she landed a job as an assistant at Vogue and began binge-eating; she ballooned to 180 pounds.

Her passion for clothes, she says, helped balance her insecurity about her body "with what I could surround myself with on the outside."

However on edge London might be, she appears to be taking her own advice: "You may be hanging on by a thread, but you don't have to look like it."