It can't be easy to be the nation's conscience. Yet

Oprah Winfrey

, 54, plays the role with such grace.

So it's doubly hard to hear that our perfect paradigm of personhood has gained 40 pounds.

"I'm mad at myself" for falling "off the wagon," O says in a brave declaration (so full of self-recrimination!) in the new edition of O.

The talk-show host, who now weighs 200 pounds (and has a body mass index of 31.8, which is obese), details her recent struggle with an out-of-balance thyroid that has instilled in her "a fear of working out."

She's hard on herself: "I'm embarrassed. . . . I can't believe that after all these years, all the things I know how to do, I'm still talking about my weight. I look at my thinner self and think, 'How did I let this happen again?' "

Valerie drops 40

Guess we know where Oprah's extra weight came from - from

Valerie Bertinelli

, who tells Fitness mag she has lost 40 pounds since March '07.

Eddie Van Halen's ex-wife, who shills for Jenny Craig, says thinness isn't just physical, it's metaphysical: "Being thin is as much a feeling as an actual appearance." She insists she didn't go on a diet to please men: "My decision to lose weight was about me - how I wanted to feel inside."

Shall I stay or go?

Is

T.R. Knight

leaving

Grey's Anatomy

or not? According to rumors, Knight, who plays the affable George, recently walked off the set in a huff and quit the show.

Yesterday, a rep from the ABC show said Knight was staying, according to Usmagazine.com. Entertainment Weekly later said on its Web site that "multiple sources" confirm that Knight has asked to be released from his contract. But, said EW, Knight uttered nary a huff or a puff, much less walked off the set.

Paula Abdul lashes out

Paula Abdul

told

Barbara Walters

on Babs' Sirius XM radio show that she is furious with

American Idol

producers for ignoring her warnings not to let longtime obsessed fan

Paula Goodspeed

audition for the Fox series. Paula says that decision fueled the fan's decision to stalk her.

"She had been writing disturbing letters for . . . almost 18 years," Paula said. "We had restraining orders at times."

On Nov. 11, Goodspeed was found dead of an apparent suicide near Paula's house. Fox did not return People.com's calls for comment.

Lopez & 52 hot dates

The devilishly handsome

Mario Lopez

- who can look so very rakish

and

innocent at the same time - will host the Miss America Pageant in Lalaland on Jan. 24. It will be telecast live on cabler TLC. "I'm thrilled to return as host," said the celeb host of celeb show

Extra!

, who MC'd the '07 pageant.

Ruffalo's brother dies

Beverly Hills police yesterday said actor

Mark Ruffalo

's brother,

Scott

, 39, died late Monday night at an L.A. hospital, a week after he was shot in the head. Two people wanted for questioning surrendered to police earlier Monday.

This column contains information from Inquirer wire services. Contact "SideShow" at sideshow@phillynews.com.