The Odyssey Premiere: Charlize Theron Details Love for Potato Chips

“The hardest thing for me was I wasn’t prepared for how that amount of processed food will affect your mood,” she continued. “I dealt with depression for the first time.”

In fact, the Mad Max: Fury Road actress realized, “What they say about ‘what you eat is who you are’ is so true, because I ate like a person who just didn’t move and I felt like that. I was lethargic and tired all the time, and that was a hard thing to break. Because it’s more mental than it is almost physical.”

And these days, Theron—who similarly gained weight for her role in 2003’s Monster—understands that her body doesn’t recover like it used to.

“I was younger [during Monster], I was like 27,” she explained. “I just didn’t snack for a week and I was back into shape; it was insane. That doesn’t happen anymore!”

For more stars who have undergone major transformations for their award-winning roles, keep reading…