You’re not going to BELIEVE who this Hollywood hottie is after his scary weight-loss

Can you tell who it is yet? We'll give you a clue: he's most likely to be whipping out his giant penis, joking around with his equally hot Australian brothers or swinging his massive hammer around (fnar).

It's Chris Hemsworth!

We know!

The Aussie star showed off his colossal weight loss on Instagram, explaining that he'd had to drop the pounds to play a starving sailor in upcoming film In The Heart Of The Sea – based on literary classic Moby Dick.

"Just tried a new diet/training program called "Lost At Sea". Wouldn't recommend it…" he captioned the snap.

Speaking on KIIS FM's Kyle & Jackie O show this week, Chris mentioned that he'd lost a total of 15kgs to get ready for the role.

"We felt as if we were going to pass out any second," he said of the difficulty in filming.

"I saw this photo of you the other day that you'd posted up - you looked like, it's like the Tom Hanks, Castaway sort of physique," Jackie told him.

"It's funny you mention Castaway because we called up Tom Hanks and he gave us some advice on how to lose the weight," Chris went on.

"So, what is the trick?" he was asked.

"Don't eat. Pretty straight-forward."

Ugh. Elsewhere this week, Chris admitted he and the rest of the cast had been eating as little as 500 calories a day as filming went on, to ensure they looked the part.

"Looking back, it was essential to doing the story justice. It was based on true events which inspired Moby Dick to be written," he added.