Matthew McConaughey may have experienced "muscle wasting" while losing weight for The Dallas Buyer's Club.

The muscular Magic Mike star has to shed 30lbs for his upcoming role in the drama. Matthew will portray a man named Ron Woodruff who contracted HIV in the 1980s through drug use.

Currently Matthew looks extremely underweight and a nutritionist who has not treated the star has shared his thoughts on the dramatic loss of bulk.

"[It] means he went into muscle wasting, which is why he is terribly gaunt," Majid Ali told Radar Online.

Matthew has spoken before about how he has been dropping the pounds as healthily as possible.

"It's a bit of a spiritual cleanse, mental cleanse," he said in an interview on web series Larry King Now a few months back.

"[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."

The Dallas Buyer's Club is slated for release in 2013.