Chris Hemsworth is on an extreme diet for his latest movie role

Chris is usually bulking up for his movie roles, but this time the opposite is true. 

For his new film In the heart of the sea, Chris has to stick to a seriously extreme diet to get down to a very low weight for some scenes.

Along with his co-stars for the movie, Cillian Murphy and Ben Whishaw, the actor is sometimes restricted to only 500 calories a day for three or four weeks. 

Speaking to Entertainment Tonight, Chris said that during this extreme preparation he spends "more time thinking about food than anything else."

It seems the only thing he currently finds comfort in is the fact that his fellow actors are in the same boat as him when it comes to dieting and he said "it's going to be pretty uncomfortable, but we'll be together in our misery"

This dramatic weight loss is for Chris' latest role in the action film set to come out later this year. The film is about the after-math following a nautical disaster which was the inspiration behind the book and film Moby Dick.

For his previous role in Thor, the 31-year-old had the task of gaining 20 pounds of muslce which he did through "nonstop" eating and serious gymming but this time he attempting the exact opposite. 

When asked what he's going to eat the minute this fasting is finished he answered "all the bad stuff – pizza, hamburgers, ice cream, anything that is not on the menu – is something you have an obsession with!"