'Modern Family' star Ariel Winter says she was fat-shamed by viewers at 13

Modern Family star Ariel Winter has said she was fat-shamed by viewers when she was as young as 13.

The US star played Alex Dunphy on the hit sitcom from the ages of 11 to 22.

ET has reported that she opens up about being trolled for her looks in an upcoming episode of Red Table Talk: The Estefans.

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"I got called a fat slut when I was 13," she says. "That was rough. Because I gained weight and my body changed, I had to wear different outfits and I wore a dress that had a cutout here (neck and chest area).

"And the headlines were dark. Fat slut was rough for me, and it continued."

Winter said while many fans of the comedy were lovely, "some were also hard on me in the way they loved Alex Dunphy and because I wasn't Alex Dunphy and didn't look like Alex, I didn't want to dress like Alex".

The actor, 23, said some fans would ask how she went from being Alex Dunphy to being "a whore" and would call her a "horrible role model".

The star said she gained 30 lb in high school as she was on antidepressants.

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She said things at the time were "rough", both at school and online, where her Instagram was flooded with comments.

Winter has previously spoken out about it being tricky to grow up on television in front of millions of people.

Last year the star told People that while she was very grateful to have her career and to have been on the much-loved sitcom, there were drawbacks.

"It’s not very easy, just because people think that just because you’re on TV, they’re entitled to your life," she said.

Watch: Ariel Winter sports a bikini as she channels The Little Mermaid with new red hair