Squid Game's Lee Jung-jae once lost 15kg and didn't sleep for two days for a film role

Offscreen, Korean actor Lee Jung-jae looks suave and is often styled in suits.

But for the 2015 movie Assassination, the Squid Game star took method acting seriously and turned scrawny for a scene.

Lee, who is well regarded for his acting skills in South Korea having starred in award-winning movies The Housemaid (2010) and The Thieves (2012), went all in for his role as a resistance fighter in the film.

The Emmy winner reportedly refused to use a body double and lost a whopping 15kg for a scene. It seems he only ate vegetables for his meals, and would drink soda while his crew members had beer whenever they went out after filming ended.

To successfully portray a mentally unstable character, Lee also didn't sleep for 48 hours before some scenes.

That's what you call dedication to your craft.