The Treme and Argo actor revealed his dramatic weight loss on the red carpet at the London premiere of Trumbo.
"I know it sounds sappy, but it was a waste," Goodman told PEOPLE "It takes a lot of creative energy to sit on your ass and figure out what you're going to eat next ... I wanted to live life better."
Goodman's new film (starring Bryan Cranston and Helen Mirren) come out in November. Check out the trailer below.