Requiem for a Dream star Jared Leto has been diagnosed with gout after undergoing dramatic weight loss for a film role. The condition is a form of arthritis and causes sudden and excruciating pain, swelling, redness and stiffness in joints. Leto's representative confirms that the gout was "caused by the dramatic weight loss for a movie role". The condition is caused by the accumulation of uric acid crystals in the joints. The 30 SECONDS TO MARS singer packed on 62 pounds (28 kilograms) for his role as John Lennon's killer Mark David Chapman in CHAPTER 27. He was required to shift the weight quickly for subsequent roles.