Image copyright Getty Images Image caption Natalie Portman was joined by actresses Eva Longoria and Constance Wu

Natalie Portman says objectification of her as a teenager made her rethink which films to work on.

The actress spoke at the Women's March in LA on Saturday about how her first fan letter at 13 was a "rape fantasy".

She also said a local radio station counted down to her 18th birthday - the date she would become "legal to sleep with".

"I felt the need to cover my body and to inhibit my expression and my work," she recalled.

"The response to my expression - from small comments about my body to more threatening deliberate statements - served to control my behaviour through an environment of sexual terrorism."

Portman said these experiences meant she developed a completely new outlook on which film roles she would accept.

Image copyright Getty Images Image caption Portman won an Oscar in 2011 for Black Swan

The 37-year-old said she "rejected any role that even had a kissing scene", while making sure to project how "bookish and serious" she was in interviews - to ensure that people treated her the right way.

Portman, who won an Oscar in 2011 for Black Swan, said that at the age of 13 she had to develop a certain mindset.

She said this lead to her developing an image that was "prudish, conservative, nerdy, serious".

This, she said, was "an attempt to feel that my body was safe and that my voice would be listened to".

Women's marches were held over the weekend, in cities across the US and around the world, to promote gender equality.

The marches also reflected the Time's Up and #metoo initiatives that have come about in the wake of the Hollywood sexual abuse scandal.

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