Actress Evangeline Lilly couldn't wait to get out of her Ant-Man and the Wasp superhero outfit because the costume's built-in corset made it unbearable to eat.

The Lost star reprises her role as Hope Van Dyne from 2015's Ant-Man for the upcoming sequel, in which she becomes budding crimefighter the Wasp, who dons a form-fitting black leather bodysuit for the gig.

Evangeline loved the sleek look of the costume, which she insists is the "coolest suit in the Marvel universe", but she didn't realise quite how restrictive it would be until she tried to eat on set.

"I like to eat, I'm a big eater; I eat all day and I eat big quantities," she told breakfast show Good Morning America, "and I'm wearing a corset in that suit, and I now know why women didn't use to eat (while wearing the undergarments).

"It's so uncomfortable to eat in a corset! You have to take tiny, little delicate nibbles all the time which was (not me), no!"

Her discovery came after spending months working closely with costume designers to perfect the outfit, and despite her food concerns, she reveled in how sexy it made her feel.

"I worked long and hard for months with the team, adjusting and tweaking and adjusting and tweaking until I felt like I would not feel like a sham walking on set," she explained to Yahoo! Entertainment. "And now I walk on set in that suit and I feel like a superhero, I feel like the Wasp, and I feel damn sexy."

However, Evangeline admits getting to that point took some time, because early prototypes of the costume failed to accentuate her curves.

"The first iteration of the suit completely flattened my butt. Totally intolerable," she quipped. "One of the iterations of the suit did not show any definition of my arms. Totally intolerable!

"We always had the question of, how large or small (do we) make the bust? Because typically comic book characters have unusually large chests. And I do not have an unusually large chest. So I really wanted to represent a more authentic version of me and not have the suit suddenly morph me into a fantasy that I am not. But you still want the right shapes, you want the right curves, you want that slightly curvaceous appeal. So finding that balance was tricky."

Fans will get to catch Lilly in action onscreen when Ant-Man and the Wasp opens in theatres from next month (Jul18).