Like any working mother, Kate Winslet had difficulty getting back into her normal routine after giving birth to third child Bear in December. But the actress admits it was actually her post-baby bod that gave her the most trouble.

“Coming back to set post-baby was a little bit like wheeling a cow into a straitjacket,” describes the actress of returning to set on her new action-adventure Divergent. “I felt like an obscure and absurd marshmallow with udders!”

But once she made sure her costumes still fit — “apart from the boob area” — she felt “it was actually OK” to be working again.

“I felt alive and less foggy-brained than I had whilst we were shooting and I was pregnant,” explains the 38-year-old. “I felt as though my senses had come back to life.”

Divergent, which opens on March 21st, provides a vastly different role for the blonde beauty than she’s ever played before.

“I hadn’t heard of the book…so I devoured it immediately,” shares Winslet, when auditioning for the part. “And on reading it, frankly, I wanted to play a baddie! It’s something I have never done.”

kate winslet

Winslet in Divergent