07/30/2013 AT 07:35 AM EDT
Kale – and lots of it.
That's how Jennifer Aniston
got in shape for her role as a stripper in her new movie, We're the Millers
The 44-year-old, who wears nothing but a bra and panties for one scene, says that she put herself on a strict diet.
"I did eat that day," she tells Access Hollywood
about filming her underwear scene. "I was on a very like, you know, greens and vegetables and lean proteins and kale."
And she was so serious about looking her best that she didn't even treat herself to a single potato chip or bite of a cupcake.
"When I really wanted to have a cheat day I had to have a kale chip," she admits.
And when she did finally strip down, Aniston made sure that her "kibbles and bits" were covered up.
"There was some major strapping and organizing," she admits. "I had no taping. I really just doubled my bras. I had a thong and then two pairs of underwear. Why I thought that was going to help protect anything is beyond me."