Los Angeles: Blake Lively says she eliminated gluten and soy from her diet to get in shape for her role in the new film 'The Shallows', which requires her to wear a bikini.

Blake Lively

"What we actually did was no gluten and no soy. It seems like it was really easy to cut out but you realise there is soy in everything... Even if it's healthy wholefoods or organic stuff, there's always soy in it," Lively said on a radio show, reports femalefirst.co.uk.

"But once you remove soy you realise you are eating just like no processed foods. That's basically what I did. No processed foods and then working out," she added.

Although it was hard work, she believes she was in the "best shape" she has ever been in while shooting the film.

"I was ready to get back in shape but I've never been in that good of shape in my whole life,' she said. To do it after having a kid is actually really nice because you see your body after having a kid and it's beautiful because you just gave birth but you're like, 'Oh my God this is not what my body looked like'," she said.