Chris Pratt

Chris Pratt's transformation from a lovable, slightly chubby actor in "Parks and Recreation" to a ripped action hero in "Guardians of the Galaxy" is one of Hollywood's most talked-about changes.

Early pictures show Pratt with a softer build and a laid-back style. His commitment to fitness and nutrition for his role as Star Lord resulted in a jaw-dropping transformation that cemented his status as a leading man.