By Gabrielle Linzer and Allison Bond
Photos of a heavy-set Kelly Clarkson taking the stage at KIIS FM's Wango Tango concert this weekend show that she may have backed off of her weight-loss program from earlier this year. In January, Clarkson debuted a slimmer physique in her video for the single, "My Life Would Suck Without You." By working out a few days a week and making diet changes to get in shape for the March 17 release of her new album, Clarkson reportedly lost 20 pounds, according to OK! Magazine. However, noticeable weight gain from a March 11 American Idol performance, coupled with recent concert photos show that Clarkson may have fallen off the wagon.
AP
To squeeze into those famous Daisy Dukes, Jessica Simpson endured two months of dieting and sweat-dripping workouts, according to People. Hitting the gym with trainer Michael Alexander and sticking to a South Beach-style diet paid off--Simpson looked lean and strong for her acting debut. But the once-slender star was recently seen looking noticeably curvier while performing at a chili cookoff in Florida.
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Sandra Bullock has admitted that obsessing over junk food drove her to overeat and then compensate for it with crash diets when she was younger. After Bullock wed husband Jesse James in July 2006, she gained again, leading to speculation that she was pregnant. Tired of combating baby-bump rumors, Bullock vowed to escape the frustrating cycle of weight gain and dieting. One thing that helped her was changing her meal staples from pizza and Diet Coke to lean meats and veggies.
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Known for his "Gladiator" physique, Russell Crowe is not your average yo-yo dieter. Despite his reputation, Crowe packed on 63 pounds for his upcoming role in Body of Lies, according to "People." Crowe may be accustomed to looking a bit more toned than the flabby CIA veteran he morphs into for the role, but that isn't to say he didn't enjoy earning his paunch. We hear from PopEater that he joked, ""I'll have that cheeseburger for breakfast, thank you!" No word on how Crowe plans on thinning out yet, but if he plans on redeeming his sex-symbol status, he'll need to cut the burgers and pump some iron.
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Early in her career, Jennifer Love Hewitt was known for her curves and slim waist. More recently, however, she filled out due to a lapse in healthy eating and steady exercise, according to iFitandHealthy.com. Overwhelmed with "photographers taking invasive pictures from bad angles," according to ABC News, Hewitt responded to criticism, claiming that she was comfortable in her skin. Soon after, however, ABC News points out that Hewitt dropped almost 20 pounds to "boost her energy." We hear from iFitandHealthy.com that Hewitt adhered to the calorie shifting diet, where you "confuse your metabolism by up-shifting and/or down-shifting into different calorie ranges, which may help your body burn more calories."
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Although she vehemently denied having an eating disorder, Nicole Richie's weight has fluctuated between thin and absolutely gaunt in recent years. She dropped to 90 pounds in fall 2006, which according to "People," was due to an inability to gain weight. When Richie became pregnant, she apparently focused on gaining weight for her baby, while also maintaining a light gym routine, but her quick transition back into her pre-baby body after she gave birth reportedly left fans worried. In the past Richie has blamed her dramatic weight loss on stress, so maybe that's the reason she lost so easily this time, too.
Jean-Paul Aussenard, WireImage | Jeffrey Mayer, WireImage
Best known for his role as Chandler on "Friends," Matthew Perry's weight has ballooned and deflated in relation to his reported numerous addictions, including painkillers and alcohol. According to "People," after Season 6 of "Friends" Perry dropped down to 145 pounds during a particularly rough period due to pancreatitis induced by "hard living and drinking hard and eating poorly." This resulted in a rehab stint at L.A.'s Cedars-Sinai Medical Center. Since his brief stay, his weight continued to fluctuate. Some of his weight gain can be attributed to recovery from addiction, while his periods of athleticism occurred when the former junior tennis champion "returned to the court and hired a personal trainer," according to "People."
When Britney Spears shimmied onto the music scene with her scandalous schoolgirl outfit at age 16, her stomach was flat as a washboard, and the rest of her body was youthfully fit. But after two babies, some said Britney wasn't looking too hot. To undo the toxic effects of hard living, we hear that she enlisted a personal trainer and got back on the dance floor. According to "OK!" Britney was so serious about getting into shape that she even cut back on her beloved Starbucks Frappuccinos!
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Far from his fit disco days in Saturday Night Fever, John Travolta's weight has swung up and down in recent years as a result of diverse movie roles and personal habits. According to the BBC, in 2001 Travolta upped his exercise routine to lose 25 pounds for Swordfish. The intense workouts, which included yoga and boxing according to AskMen.com, must not have lasted, as Travolta looked pleasantly plump during a shirtless romp in his 2007 film Wild Hogs. According to reports from the Daily Mail, Travolta claimed that "Life is too short to diet constantly" and declared an intense love of food -- both of which go far in explaining his yo-yoing.
AP | Jim Spellman, WireImage
Christian Bale worked out like a maniac while doing both intensive cardio and weight-training sessions for his brutal role in 2000's American Psycho. Four years later, he dropped a reported 63 pounds, by eating only an apple and a can of tuna every day, to play a skeletal drug addict in The Machinist.
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Jared Fogle, a.k.a., "the Subway guy" was recently spotted in the Miami airport toting some extra baggage -- and not the kind on two wheels either. 
