Leonardo DiCaprio truly embraced his role as a real-life frontiersman in The Revenant by eating "raw bison liver" and sleeping in animal carcasses while shooting in freezing temperatures.
Director Alejandro Gonzalez Inarritu's new film features the actor as 19th century fur trapper Hugh Glass, who was left for dead by his associates after being mauled by a grizzly bear.
The grueling shoot lasted nine months and took the cast and crew from Canada to Argentina, and DiCaprio admits it was one of the toughest movies he has ever done.
He tells Yahoo! Movies, "I can name 30 or 40 sequences that were some of the most difficult things I've ever had to do.
"Whether it's going in and out of frozen rivers, or sleeping in animal carcasses, or what I ate on set. (I was) enduring freezing cold and possible hypothermia constantly."
The shoot even put DiCaprio's stomach to the test as he had to munch on raw offal.
"I certainly don't eat raw bison liver on a regular basis," DiCaprio says. "When you see the movie, you'll see my reaction to it, because Alejandro kept it in. It says it all. It was an instinctive reaction."
The film, which also stars new dad Tom Hardy, is based on Michael Punke's 2002 book of the same name and has already been tipped for awards season glory - and DiCaprio insists the hype is worth it.
He adds, "It's going to be one of the most unique film-going experiences that audiences have seen in modern times."