Peter Jackson directed the film 'King Kong' in 2005. He lost something during the filming, however. What?

Explanation

Peter Jackson (born 1961) is a film director from New Zeland. He directed the 'Lord of the Rings' trilogy. The films are based on the J.R.R. Tolkien books 'The Fellowship of the Ring', 'The Two Towers' and 'The Return of the King'. Before that he was known for hus humoristic gore films such as 'Braindead/Dead Alive' (1992) and 'Heavenly Creatures' (1994). Peter Jackson lost an amazing 32 kg during the production of King Kong in 2005.