Jennifer Aniston flaunts flat abs in GQ: Hottest celeb body?

Jennifer Aniston is 43 -- and she still has flatter, tighter abs than just about anyone in Hollywood, as you can see in the March issue of GQ magazine. Posing in a black bra and miniskirt with her "Wanderlust" co-star Paul Rudd, she says: "Forty’s great! Oh, my God, my thirties blew! Forties are great." A little dig at Brad Pitt there, perhaps?

SODAHEAD SLIDESHOW: See the celebrities with the hottest bodies.

If Aniston did appear to be a little curvier in recent months -- sparking the usual pregnancy rumors -- it's because she quit smoking. "Well, I recently quit smoking, and you do put on some extra pounds! It makes a difference, especially if you're not 20," she says.

But she is not -- we repeat -- pregnant right now. "I'm not having triplets. Not having twins. Nor am I having one baby. I did not elope… You heard it here. I’m not knocked up now."

Meanwhile, Rihanna's personal trainer, Harley Pasternak, has revealed how SHE got her amazing Grammys bod. "She's got such a beautiful body naturally. With someone like her, it's about the fine tuning," he told People, explaining that the sexy singer usually works out at least three times a week for around 25 minutes, doing cycling, skipping, stationary jogging and jumping jacks. She also eats lots of protein, including bean-based foods, and tries to eat five small meals a day.

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From Aniston to Rihanna to new Sports Illustrated cover girl Kate Upton, let us know: Which celeb has the hottest body?

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