Chris Hemsworth is known for his hot bod but the 32-year-old looked shockingly different in his new Instagram photo.

The father of three looked gaunt (and dirty AF) in the selfie that he posted on Sunday. The Aussie embarked on an intense 500-calorie a day diet for his new film, In the Heart of the Sea.

"Just tried a new diet/training program called "Lost At Sea". Wouldn't recommend it.. #IntheHeartoftheSea"

In an interview with Entertainment Tonight, Hemsworth said it was hard to not eat, "I spend more time thinking about food than anything else."

"We have to shoot the really skinny stuff where we drop down to 5, 6, 700 calories a day, a good three or four weeks and it's going to be pretty uncomfortable, but we'll be together in our misery," he said.

In the film, which is directed by Ron Howard, the Thor actor plays Owen Chase in the movie which is inspired by Moby Dick. Owen Chase is a sailor who gets stranded at sea for 90 days and try to overpower a massive whale who eventually destroys their ship.

In The Heart Of The Sea sails into theaters on Dec. 11.