The Captain America: Civil War star has become known for her stylish looks at film premieres and other high-profile events, but the 27-year-old admits she always struggles with confidence issues because of her bust.

"The clothes we're expected to fit into aren't sizes; they're samples," the beauty tells Allure magazine. "They're not made for chicks with boobs, so I'm very self-conscious about having them."

She adds, "I have fun choosing an outfit for my best friend's wedding, but not (something) I'm going to be judged in."

That's not the only thing Elizabeth feels judged about - she is still frequently compared to her older sisters, twin actresses-turned-fashion moguls Mary-Kate and Ashley Olsen, but it's something she has learned to live with.

"You know you're going to be compared (with them) for the rest of your life," she says. "You grow up and get over it, and you love your family regardless."

However, there's one thing Elizabeth doubts she will ever grow accustomed to - living under the glare of the paparazzi.

"Being a celebrity for not doing anything, I don't understand that," the actress explains. "I won't go to certain restaurants because I don't want to be photographed."

The presence of snappers at her favourite farmers' market in Los Angeles has even prompted Elizabeth to stay away from the celebrity hotspot: "I had to find a different kind of sauerkraut!," she laughs.

Elizabeth's desire to go unnoticed in public has also influenced her decision to stay away from social media, which many stars use to keep in touch with fans and boost their popularity.

"I think that's another reason why I don't want to do all that, because I want to be able to just be," she told Britain's Sunday Times Style Magazine last month (Apr16). "I'd rather disappear into my breakfast nook and read the news and drink coffee than flick through Instagram."