Jen's Best Body at 41: How She Lost 7 Lbs. in 7 Days!

For  Jen Aniston, 41, life is fabulous! While recently shooting Just Go With It with Adam Sandler, Jen looked hotter than ever. “She looked as if she’s lost a dress size,” a witness tells OK!. “She was really petite and avoided the food on the craft services table. She has discipline.”

Thanks to self-control and a newfound philosophy on eating and exercise, Jen’s achieved her best body ever.

“She recently lost 7 pounds in seven days and she is totally ecstatic,” a source tells OK!.

FOR MORE ON JEN'S FUN DIET AND EXERCISE PLANS, PICK UP THE NEW ISSUE OF OK! — ON SALE EVERYWHERE THURSDAY!

ALSO IN THE NEW ISSUE OF OK!:

Extreme Makeovers: Why more stars than ever are going under the knife to stay on top in Hollywood. Does Heidi Montag want more plastic surgery? Did Kate Hudson have something done? OK! compares the before and after pictures and talks to some expert plastic surgeons.

The Kardashians: Kim and Kourtney continue to fight the weight wars and are getting their bods in even better shape. Find out what kind of diet plans and exercise regimes are really working for the Kardashian sisters.

Dancing With the Stars: All the intrigue you won't see on the show from Cheryl Burke and Chad Ochocinco’s food wars to Nicole Scherzinger’s struggles with partner Derek Hough to Olympic skater Evan Lysacek’s gum obsession.

Plus:

Will Prince William and Kate Middleton be finally making plans for that big Royal wedding?; Brad Pitt and the kids have a fun playdate at a playground in Venice, Italy, while Angelina Jolie films her next flick; AnnaLynne McCord and Kellan Lutz goof around at an L.A. Lakers game; Who are the hottest mom's in Hollywood and how do they juggle it all? Halle Berry, Gwen Stefani and Jennifer Garner are just a few of OK!'s picks!; Find the perfect gift for every mom on your shopping list from the practical ones to the indulgent ones; Get flawless skin like Kate Winslet with these pro tips and celebrity picks; Lasting impressions with Glee star Cory Monteith.