Matthew McConaughey hopes to lose 30 pounds to play a gaunt HIV victim in upcoming movie "The Dallas Buyers Club." He will play Ron Woodruff, who smuggled life-saving drugs across the Mexican border after contracting the disease during the 1980s.

McConaughey, who recently bulked up to play a fit male stripper in "Magic Mike," has been forced to slim down for the part, which starts filming in September.

He told Larry King's new Ora TV web series, "I'm losing some weight. I've got a role coming up in the middle of September. I've lost about 15 pounds, I've gotta lose about 15 more. I should not look healthy by the time I'm doing (filming) this."

The actor, 42, says the strict diet is hard on his body. "It's a bit of a spiritual cleanse, mental cleanse. (I'm) drinking a lot of tea. It takes a while for your body to understand that it has to feed off of itself and that you're not going to give it something else from the outside," he said.