McConaughey: Nolan is ambitious
"(He's) excellent. Different to anything I've ever done for sure," he said, adding: "He's incredibly ambitious and this is the most ambitious film he's ever directed."
The 44-year-old, who is up for the best actor Oscar for his performance, plans to abstain from alcohol at the Academy Awards - at least until he's away from the stage.
"I like wine, but if I'm presenting, then I do it after that. I actually like to hit the stage without anything, but after that, I always have a glass," he said.
"Oh, he has bags of popcorn. He comes in with grocery bags of things so I've been partaking in a few of those," he added.
:: Dallas Buyers Club is in cinemas now.