Inside Brendan Fraser's Transformation for The Whale

To portray Charlie, an online English teacher with severe obesity, Fraser underwent prosthetics and makeup that could take up to six hours to apply. The prosthetics, created by Adrien Morot with a 3D printer, at times weighed up to 300 pounds.

Fraser told Vanity Fair that when he first laid eyes on the prosthetic suit, hung on a mannequin, he was taken aback: "It was that beautiful and that arresting."

When wearing the suit Fraser's mobility was severely limited, requiring him to be aided with sitting, moving and standing up.

Fraser said the suit was "cumbersome, not exactly comfortable," and described it as "almost like a straight jacket." But noted its technical detail down to it being "airbrushed by hand, to look identical as would human skin, right down to the hand-punched hair."

He also made sure to be as accurate and sensitive as possible, working with the Obesity Action Coalition. "I learned quickly that it takes an incredibly strong person inside that body to be that person," he said of the experience. "That seemed fitting and poetic and practical to me, all at once."

Hollywood has come under fire in recent years over the use of "fat suits" and the often mocking depiction of obese people.

Speaking of his suit, Fraser said, "I looked at other body suits that had been used in comedies over the years, usually for a one-note joke."

"Whether intended or not, the joke is, it defies gravity. This was not that," he said.

The film is based on the 2012 Samuel D. Hunter play of the same name, with Hunter also developing the screenplay.

"The Whale" also stars Sadie Sink, Hong Chau, Samantha Morton and Ty Simpkins, it hits theaters December 9.