But on Tuesday, Quinn disclosed a difficult piece of her past that she had kept private: She was bulimic for a decade in her teens and 20s, went to rehab for it at 26 and considers herself a recovering alcoholic to this day.
"I've always held the belief that the more honest we are, and the more we kind of take things that are our own personal secrets and make them public, it's really transformative for us but also for society," the Democratic City Council speaker told an audience of students at Barnard College, where she described an eating disorder that began as a quest for self-perfection and a sense of power as she cared for her dying mother. A drinking problem developed in tandem as she struggled to contend with the pain and upheaval of her family's loss, Quinn said.
The revelation came in the thick of the heated mayoral race, in which Quinn is the Democratic front-runner but has seen her lead ebb somewhat recently, and ahead of a Quinn memoir that's due out next month.
Her discussion of her past, previewed in a New York Times story before her talk Tuesday, adds an element of personal struggle to a public figure who has a brassy image and embraces it. Her famously loud voice sometimes went quiet and paused as she spoke about topics she said she found difficult to discuss.
While Quinn faced questions about whether the disclosure was an attempt to temper her public persona, she said it was anything but: "I don't know that being a bulimic or an alcoholic makes that image that much softer, anyway," she said, to laughs from the audience.
She said she decided to make her past problems public now because she was emotionally ready to do so, had been touched by strangers' responses to her wedding to her longtime partner last year, and wanted to use the spotlight of the mayor's race -- and the book offer -- to share her experiences in hopes of easing others'.
"That's really what this is about: An opportunity for me to ... come out in another way that I needed to, and to help other people, hopefully," she told students at the all-women's college.
"One of the things about challenges like bulimia or eating disorders or alcoholism is: You think you're the only person. You know what I mean? I thought I was the only 16-year-old girl in the world who had no ability to deal with her mother dying," she said
Still, perhaps with voters' questions in mind, Quinn, 46, emphasized that she had gotten help for her problems and feels "really great and really healthy" now. After leaving rehab, she drank rarely -- perhaps a glass of wine a month -- for years and then stopped altogether about three years ago, as part of improving her diet and exercise habits, she said.
By disclosing her struggle with bulimia, a disorder that's considerably more common in women than in men, Quinn could foster empathy among women voters, while at the same time reshaping a political narrative that has sometimes portrayed her as aggressive, said Barbara Koziak, a political science professor who also teaches in the women's studies program at St. John's University in New York. The portrayals of Quinn have also stirred questions about whether that narrative would be a non-story if she were a man in a city not exactly known for reserve.
"I think she's really trying to manage some of this treacherous terrain now by presenting more of her personal life," Koziak said.
Quinn's approach impressed Tabia Santos, a Barnard senior who heard Quinn's talk.
"I think that we, as a society, are moving toward being open ... so it's better for people to be open and upfront about things," said Santos, a 21-year-old neurology major who hasn't yet settled on a candidate in the mayor's race.
An estimated 1.5 percent of U.S. women and 0.5 percent of men suffer at some point in their lives from bulimia, or a compulsive cycle of binge eating and then inducing vomiting, studies have found. The syndrome can be associated with gastrointestinal, cardiovascular and other problems.
Quinn was a teenager on Long Island, fretting about her weight, when she overheard other girls talking about it in her high school locker room, she recalled.
Then came a wrenching summer: Her mother was deaf and dying of cancer. Quinn was the family member whose lips she could best read, the one who delivered all the bad medical news.
She began sneaking to her room to devour hordes of sweets, and then throw up. Around the same time, she started going out with friends and drinking.
Bulimia "gave me a sense of control over my eating, over a small part of my world. And the alcohol gave me a little bit of an escape," she said. "And that's what started it, and it continued until, you know, I asked for help."
Associated Press researcher Rhonda Shafner contributed to this report.
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Copyright 2013 The Associated Press.