Seth Rogen leaving a Starbucks in West Hollywood.
Los Angeles, California - 14.04.09

The Knocked Up star was filming new film Observe and Report in Albuquerque when he realised his health really wasn't it should be.

He explains, "I'm somebody who can barely breathe in Los Angeles, which is at sea level. I can't walk up a flight of stairs. Albuquerque is at an elevation of about two miles and the air is very thin."

And Rogen tells Playboy magazine, "There were some big action scenes. Every day it felt as if I were climbing Everest. So the stunts were really hard, much harder than they should have been.

"I realised if I was going to make Green Hornet I needed to lose weight. Aside from how the character is supposed to look, I couldn't physically make the movie in the shape I was in. It would have literally killed me."

Source: WENN