The Thor star is used to bulking up for his action films, but this time he battled constant hunger pangs for the real-life maritime epic, which documents the sinking of a whaling ship in the Pacific Ocean in 1820 - the disaster which inspired Herman Melville's classic tale Moby-DICk.

Hemsworth tells U.S. news show Entertainment Tonight, "We had to shoot the really skinny stuff where we drop down to 5, 6, 700 calories a day, a good three or four weeks..."

The actor admits the experience was "pretty uncomfortable", but he was thankful he and his co-stars Cillian Murphy, Ben Whishaw and Paul Anderson were "together in our misery" as they also had to endure the extreme diet during filming in 2013.

In the Heart of the Sea is due for release in December (15).