Val Kilmer BEFORE(01 of42)
Open Image ModalShown here on November 2, 2012 in Austin, Texas. (credit:Rick Kern/WireImage)
Val Kilmer AFTER(02 of42)
Open Image ModalAretha Franklin BEFORE(03 of42)
Open Image ModalAretha Franklin AFTER(04 of42)
Open Image ModalToday, she's slimmed down even more, and continues to perform, with tour dates booked well into 2015. Shown here on Friday, Dec. 12, 2014. (credit:Evan Agostini/Invision/AP)
Jill Scott BEFORE(05 of42)
Open Image ModalShown here on October 3, 2012. (credit:Andrew H. Walker/Getty Images for Lifetime)
Jill Scott AFTER(06 of42)
Open Image ModalJessica Simpson BEFORE(07 of42)
Open Image ModalJessica Simpson's hard work at her weight is no secret — the Weight Watchers spokesperson is quite open about her what she eats and how much she exercises. Shown here on December 3, 2013. (credit:Michael Stewart via Getty Images)
Jessica Simpson AFTER(08 of42)
Open Image ModalTom Arnold BEFORE(09 of42)
Open Image ModalWhen his son was born in April, 2013, Tom Arnold vowed to lose weight to stay healthy for him. Shown here on July 16, 2013. (credit:Richard Shotwell/Invision/AP)
Tom Arnold AFTER(10 of42)
Open Image ModalRosie O'Donnell BEFORE(11 of42)
Open Image ModalAfter Rosie O'Donnell had a heart attack in 2012, she started thinking more about her health and weight. Shown on October 24, 2013. (credit:Beck Starr via Getty Images)
Rosie O'Donnell AFTER(12 of42)
Open Image ModalMelissa McCarthy BEFORE(13 of42)
Open Image ModalShown on April 18, 2013. (credit:Al Powers/Powers Imagery/Invision/AP)
Melissa McCarthy AFTER(14 of42)
Open Image ModalMelissa McCarthy has been asked about her weight many times in interviews, but according to Hollywood Life, she recently lost 45 pounds in an attempt to stay healthy for her kids. Shown on November 16, 2014. (credit:Gregg DeGuire/WireImage)
Zach Galifianakis BEFORE(15 of42)
Open Image ModalShown here on Oct. 28, 2011. (credit:AP Photo/Katy Winn)
Zach Galifianakis AFTER(16 of42)
Open Image ModalChristina Aguilera(17 of42)
Open Image ModalChristina Aguilera(18 of42)
Open Image ModalNicole "Snooki" Polizzi(19 of42)
Open Image ModalHer 4"9 frame makes it pretty easy for this reality TV star to both put on and take off weight, and before her pregnancy (and on Jersey Shore), she weighed approximately 146 pounds. (Shown here February 15, 2011) (credit:Ethan Miller/Getty Images)
Nicole "Snooki" Polizzi(20 of42)
Open Image ModalBeyonce Knowles(21 of42)
Open Image ModalBeyonce(22 of42)
Open Image ModalNaya Rivera(23 of42)
Open Image ModalThe Glee actress has always been able to rock the short cheerleading skirts that are part of her costumes, but much as her character changed this season on the show ... (credit:Alberto E. Rodriguez/Getty Images)
Naya Rivera(24 of42)
Open Image Modal... so did her look, which became far leaner and more sultry. And yes, with more skin. (credit:Jason Merritt/Getty Images)
Kelly Clarkson(25 of42)
Open Image ModalKelly Clarkson(26 of42)
Open Image ModalAnd though as of November, the star is now pregnant (and told Parade magazine, "Everybody calls me fat all the time, so I can’t wait to have a reason, instead of everybody just being a jerk!”), she was looking pretty bodacious in 2013. (Shown here February 10, 2013) (credit:Getty Images)
America Ferrera(27 of42)
Open Image ModalAmerica Ferrera(28 of42)
Open Image ModalHilary Duff(29 of42)
Open Image ModalHilary Duff was one of the few Hollywood moms who was very vocal about taking her time to lose the 50 pounds she gained while pregnant (son Luca was born in March 2012), and for that, we applaud her. (Shown December 7, 2012) (credit:Alexandra Wyman/Getty Images For March Of Dimes)
Hilary Duff(30 of42)
Open Image ModalAs we do for how awesome and healthy she looks now, having started boxing with a personal trainer in late 2012 and rocking some serious shoulders this year. (Shown November 6, 2013) (credit:Jason Merritt/Getty Images for Fresh-Tops)
Graham Elliot(31 of42)
Open Image ModalGraham Elliot(32 of42)
Open Image ModalBritney Spears(33 of42)
Open Image ModalThe teen star turned mom of two quite fairly looked prettily average for the past few years. (Shown May 11, 2013) CARSON, CA - MAY 11: Singer Britney Spears onstage at 102.7 KIIS FM's Wango Tango 2013 held at The Home Depot Center on May 11, 2013 in Carson, California. (Photo by Kevin Winter/Getty Images) (credit:Getty Images)
Britney Spears(34 of42)
Open Image ModalQueen Latifah(35 of42)
Open Image ModalQueen Latifah(36 of42)
Open Image ModalAnd the 5"10 singer and actress certain succeeded, looking completely stunning in form-fitting dresses throughout 2013. (Shown Oct. 26, 2013) (credit:Charles Sykes/Invision/AP)
Khloe Kardashian(37 of42)
Open Image ModalAlright, we're just going to say it and get it over with — it's tough to "keep up with" your sisters when they're Kim and Kourtney Kardashian. (Shown March 2, 2013) (credit:Frazer Harrison/Getty Images)
Khloe Kardashian(38 of42)
Open Image ModalJordin Sparks(39 of42)
Open Image ModalJordin Sparks(40 of42)
Open Image ModalThis year, it looks like she's worked even harder on her body, with the gorgeous 6"0 beauty making us incredibly jealous of her arms (and legs!). (Shown Dec. 10, 2013) (credit:Slaven Vlasic/Getty Images)
NeNe Leakes(41 of42)
Open Image ModalNeNe Leakes(42 of42)
Open Image Modal