12/22/2008 at 01:00 AM EST
There'd been whispering about it for weeks, but leave it to Oprah
Winfrey to shout it out loud: Yep, she has hit "the dreaded 2-0-0," as she writes in the January 2009 issue of O
. Posed alongside a cutout of herself in leaner times, Winfrey admits in a candid essay that, after getting down to 160 lbs. in 2004, she has gained back 40 lbs. in the last four years. "I'm mad at myself. I'm embarrassed," she writes. "I didn't just fall off the wagon. I let the wagon fall on me."
Winfrey's yo-yo battle with the bulge spans most of her career, from her triumphant marathon run in 1994 to earlier this year, when she announced she'd been diagnosed with a thyroid disorder that left her fatigued and feeling heavy. That condition—plus a busy 2008 that included fallout from a sexual misconduct scandal at her school for girls in South Africa and her pivotal involvement in Barack Obama's campaign—caused Winfrey, 54, to miss workouts and slide into poor eating habits. "I took myself off my own priority list," she writes in O
Now her challenge is to get healthy again—this time, she hopes, for good. "I can't believe that after all these years, all the things I know how to do," she writes, "I'm still talking about my weight."