The 43-year-old actor said he is losing the weight in a "really healthy way" and is "not being starved" for his upcoming film The Dallas Buyers Club, even though he's dropped to a shocking 143 pounds, reported Radar online.
"I feel fine. I really do," the six feet tall former hunk said about his shocking transformation.
The movie is based on the true story of Ron Woodruff, a drug-using straight man who was diagnosed with full-blown AIDS in 1986 and fought the government and the US pharmaceutical industry to get access to anti-viral drugs being used against HIV in other countries.
"I got the means to lose the weight in a really healthy way. I'm eating fresh fish. I'm just eating small amounts. I'm not being starved," McConaughey said.
Photos from the set show the usually buff Texan on set looking incredibly skinny and gaunt, but he says he's not suffering from dropping the pounds.
"I'm sleeping well. I've got clean meals that I'm cooking for myself. It's just really an exercise in discipline. If anything, it's as much a spiritual journey as it is physical. My body is fine. I'm taking care of myself. Everything has shrunk quite a bit."
