Biggest Celebrity Transformations Of 2011 (PHOTOS)

Although it's easy to forget, celebrities are only human.

As the years change so do they and 2011 was no exception. What is shocking however, is how much some of them have changed in just a year.

Whether it's weight loss or weight gain, a boob job or a nose job, all of these celebs have undergone huge physical transformations big enough to keep us guessing what they'll look like this time next year.

Check out the biggest celebrity transformations of 2011:

Loading Slideshow

• July 2010

  Ali Lohan before .... Credit: Getty

• September 2011

  Ali Lohan after .... The 17-year-old model looks undeniably different but still denies that she had any plastic surgery to alter her appearance.

• November 2010

  Vienna Girardi before .... Credit: Getty

• August 2011

  Vienna Girardi after ... The 25-year-old former contestant on "The Bachelor," admitted on Twitter that she'd gone under the knife to get a nose job. Credit: Getty

• March 2010

  AnnaLynne McCord before ... Credit: Getty

• November 2011

  AnnaLynne McCord after... This fall, the '90210' actress suddenly started busting out of her costumes with some new found curves. Credit: Bauergriffin

• September 2010

  Bristol Palin before.... Credit: Getty

• July 2011

  Bristol Palin after .... The former "Dancing With The Stars" contestant claims she had "corrective jaw surgery" and that's what is responsible for her new face. Credit: Getty

• December 2010

  Christina Aguilera before.... Credit: Getty

• November 2011

  Christina Aguilera after .... It's been a long time since the singer's "Genie In A Bottle" days, but fans were shocked to see some of the outfits Christina has been squeezing herself into. Credit: Getty

• October 2010

  Jonah Hill before.... Credit: Getty

• December 2011

  Jonah Hill after .... The "Superbad" actor looks like a completely different person after setting and meeting a goal to lose 30 lbs for his demanding role in the action-packed "21 Jump Street." Credit: Getty

• November 2010

  Jordin Sparks before.... Credit: Getty

• December 2011

  Jordin Sparks after.... The "American Idol" sixth-season winner dropped a ton of weight and seems thrilled to be showing off her new fit body. Credit: Getty

• March 2010

  Kirstie Alley before .... Credit: Getty

• September 2011

  Kirstie Alley after.... The actress and "DWTS" alumna turned heads when she lost 100 lbs this year. The 60-year-old's dramatic new look prompted rumors of weight loss surgery and an eating disorder, <a href="http://www.huffingtonpost.com/2011/09/21/kirstie-alley-denies-having-surgery-and-bulimia-after-losing-100lbs_n_974446.html" target="_hplink">both of which she denies having. </a> Credit: Getty

• December 2010

  Kate Gosselin before .... Credit: Getty

• October 2011

  Kate Gosselin after .... Though she denies having a facelift, the mother of eight doesn't quite look the same as she did last year. Credit: Getty

• September 2010

  LeAnn Rimes before.... Credit: Getty

• August 2011

  LeAnn Rimes after ... The 29-year-old country singer lost a shocking amount of weight this year and turned to Twitter several times to defend her super skinny body.

• February 2010

  Raven Symone before... Credit: Getty

• August 2011

  Raven Symone after ... The 26-year-old actress shed some major pounds in 2011. Credit: Getty

• November 2010

  Ricki Lake before .... Credit: Getty

• November 2011

  Ricki Lake after.... "Dancing With The Stars" helped the 43-year-old TV personality drop at least 23 lbs. Credit: Getty

• December 2010

  Snooki before .... Credit: Getty

• December 2011

  Snooki after ... The "Jersey Shore" star has been trying get to her goal weight of 98 lbs and it looks like she hit her goal. Credit: Snooki, Twitter