Matthew McConaughey in 'Dallas Buyers Club'

After seeing Matthew McConaughey's toned torso in Magic Mike (2012), you'd be forgiven for thinking that he shouldn't change a thing. But for his next film, McConaughey chose to portray a very sick man -- and he adjusted his body accordingly. To play real-life AIDS-medication-smuggler Ron Woodroof, who contracted HIV from drug use, the actor dropped a startling 38 pounds from his lean frame. "I'm kind of looking at it as a cleanse; it's a bit of a spiritual cleanse, mental cleanse," the actor said in July 2012, halfway through his strict weight-loss regimen. By the time he'd reached his goal weight, McConaughey admitted he had "35 percent less energy" -- and was fantasizing about "a half-pound cheeseburger with three types of cheese!"