You can believe your eyes: The balding, paunchy guy in the above photo really is Matthew McConaughey. Unafraid of physical transformation, having dropped 40-odd pounds for his Oscar-winning Dallas Buyers Club role, the handsome actor cast vanity to the wind for his new movie, Gold, which gets a wide release this weekend.

He packed on pounds, shaved his head, and had dental and facial prosthetics applied to his teeth and nose to play Kenny Wells, a prospector with a pipe dream that takes him to the Indonesian jungle in pursuit of riches that come at a price.

Set in the 1980s in Reno, Nevada, Gold is based on true events in the life of David Walsh, who was hefty and homely. Director Stephen Gaghan (Syriana, Traffic) ordered a fat suit for McConaughey, but he opted to do it naturally with milkshakes, cheeseburgers and beer, he revealed in a Q&A session after a Variety Screening Series showing of the movie.

McConaughey, also one of the producers of Gold, talked about becoming Wells, why he related to him, and reminisced about his very first acting job. Hint: It’s not Dazed and Confused.

“I met all these guys who would never have a path to the American Dream through the front door. They’d always have to sneak in a window, con their way in and bullshit their way out. They all had insatiable appetites, huge hearts.”

You completely transformed. How did you do it?
Cheeseburgers and beer. Putting on the 45 is a lot more fun than taking it off. My head was shaved and then it was a hairpiece on top. David Walsh was quite… swollen, and had the insatiable spirit of these guys that I met growing up—drinking, eating, every desire. They had a weight and a spirit about them.

That was my father, buying a fake Rolex watch that he thought was worth $22,000 and paid $3,000 for it but it wasn’t worth $300. It was really about the deal for him—it was fun. My dad was always into shady deals. In the ’80s he was trying not to go bankrupt. I’d go on the road with him to try to collect on debts, to try to shame the guy into paying. It worked sometimes, other times it didn’t.

Things weren’t going well for him but he always said, ‘Today’s the day when I’ll hit that lick.’ He didn’t but he kept trying. I met all these guys who would never have a path to the American dream through the front door. They’d always have to sneak in a window, con their way in and bullshit their way out. They all had insatiable appetites, huge hearts.

What attracted you to the role of Kenny Wells?
I admired him from the get-go. This is one of three scripts in 24 years that when I read it I said, ‘I have to do it.’ I know this guy inside and out. Kenny is a guy who’s throwing Hail Marys, running under and catching them and seeing what he can pull off, and he does it many times in the story. Have I done that? Yeah.

I haven’t been in Kenny Wells’ position. But 10 years ago I was looking at my life and decided to take time off. Can I find some work that is going to scare me, let me love, and have as much rage, sadness, laughter, joy as life does? Those roles weren’t there for me. I had to take off and said no. First I had to have a talk with my wife, my business managers—do I have enough money to pay the rent? I love to work and I knew I was gonna get antsy and anxious. It was dry for a year and a half. It was an un-branding.

I was away for a while, but I became directors’ new good idea because I hadn’t been around. It was a conscious move on my part even though I didn’t know where I’d end up.

It worked, though—you did The Lincoln Lawyer, Killer Joe
Then I did Mud, Magic Mike and Dallas Buyers Club.

What was your first job in the business?
Unsolved Mysteries. I played a victim who was shot seven times by a guy who had exposed himself to some kids in the neighborhood. I thought I was really hot stuff, because they caught the guy two weeks later.