By Piya Sinha-Roy LOS ANGELES (Reuters) – Jared Leto, the former teen heartthrob who left Hollywood to become a rock star, won the best supporting actor Oscar on Sunday in his return to movies as an HIV positive transgender woman in “Dallas Buyers Club.” Leto, 42, won over both critics and audiences with his portrayal of Rayon in the 1980s era AIDS drama, and was seen as favorite for the supporting actor Oscar. He beat out Bradley Cooper, Barkhad Abdi, Jonah Hill and Michael Fassbender. But it was Leto’s return to film in “Dallas Buyers Club” that piqued the interest of audiences, especially as the actor documented a weight loss of 30 to 40 lbs (13-18 kg) to transform himself into HIV-positive character Rayon.