Chris Hemsworth lost an insane amount of weight for his new movie

We know him best as Thor in the movies from the Marvel Universe, but for his next film, Chris Hemsworth abandoned his buff body to play a man lost at sea.

For the upcoming Ron Howard-directed adventure "In the Heart of the Sea," Hemsworth plays the first officer of a whaling ship that's sunk by a sperm whale. He and the survivors are then shipwrecked at sea for 90 days.

Yesterday, the actor showed just how far he went to play the role, tweeting this picture of his frail physique by the end of filming.

Talking to Entertainment Weekly over the summer, Hemsworth said that he had already slimmed down for the film "Blackhat," but then went down another 15 pounds before starting "In the Heart of the Sea."

He and other cast members ate only 500 calories a day leading up to filming the final scenes, when they are adrift at sea with no food or water.

"In the Heart of the Sea" opens in theaters December 11.