Olivia Wilde feels "unstoppable" in low-rise jeans and a sweatshirt.

Olivia Wilde

Olivia Wilde

The 'Booksmart' star joked she is "still pretending to be a teenager from the early aughts" with her outfit choices, but insists they are the most comfortable to wear.

She said: "I'm still pretending to be a teenager from the early aughts. My most comfortable state is when I'm wearing low-rise jeans, sneakers, and a sweatshirt. In that, I am unstoppable. And if I'm in a high-waist jean, I can't let my gut expand. When I see pictures of people like Paul Feig directing in full-on outfits, I'm like, 'How?'"

And Olivia has spoke of how close she is to her stylist.

Speaking to InStyle magazine's Badass Women issue, she added: "My stylist, Karla Welch, is one of my best friends. She knows I love a strong shoulder and anything that makes me feel powerful. That doesn't mean I don't love a flowy frock here and there, but you learn what makes you feel like your best self."

Meanwhile, Olivia previously opened up about her beauty routine, revealing she changed her beauty products when she was pregnant with her children.

The mother-of-two - who has Otis, five, and Daisy, three, with her partner Jason Sudeikis - said: "Since having kids, my relationship to health and beauty has become much more thoughtful. I used to slather anything on my skin and not care what it was made out of. I've always loved the decadence of beauty products, but at the point when I first started having children - when I was suddenly responsible for another living being - I became conscious of what I was putting on and in my body. I wish we would be more conscious when it's just for ourselves."