Il Nuovo Postiglione - Sydney Sweeney details preparation to play female boxer

But she was prepared to talk about her waistline, namely how she gained weight to transform her appearance for a role that could make her an Academy Award contender.

"A lot of Chick-fil-A, a lot of Smucker's, a lot of milkshakes, a lot of protein shakes," Sweeney told an adoring crowd following the world premiere at the Toronto International Film Festival.

"I trained three times a day, every day."

The film recounts a life that director David Michod described as "incredible."

"Particularly incredible that I'd never heard it before" until working on the film, he said after the premiere.

Christy Martin, 57, was born Christine Salter in the US state of West Virginia, the daughter of a coal miner.

In the late 1980s she started boxing, gradually becoming the sport's first true female star, backed at times by iconic boxing promoter Don King.

The film addresses her efforts to suppress her sexuality as a young woman and the abuse she suffered from her trainer and eventual husband Jim Martin, played by Ben Foster.

Martin stabbed and shot his then-wife and remains in prison over her attempted murder.

Foster said he was "curious" about meeting Jim Martin when preparing for the role, but ultimately decided that would be "disrespectful," instead shaping his performance around the issues of "coercive control and domestic violence."

"Her story deserves to be told," Sweeney said of the fighter, who has resumed using her maiden name, Salter.

"It was incredible being able to completely embody such a powerful woman," Sweeney said.

Ahead of the premiere, the Emmy-nominated actress -- best known for roles in the series "The White Lotus" and "Euphoria" -- dodged questions about the internet meltdown triggered by her ad campaign for the clothing brand American Eagle.

Some social media users were outraged, saying the wordplay of the tagline "Sydney Sweeney has great jeans," coupled with the actor's blue eyes and blonde hair, has racial undertones.

"Genes are passed down from parents to offspring, often determining traits like hair color, personality and even eye color. My genes are blue," Sweeney, wearing denim on denim, says in one video.

The ad's defenders have included President Donald Trump.

"Sydney Sweeney, a registered Republican, has the HOTTEST ad out there,” he posted last month on his Truth Social platform.

Salter, in Toronto for the premiere, praised Sweeney's transformative performance.

"She wasn't the beautiful, sexy Sydney. She was the tough, rugged Christy in this movie and I think it's awesome," said Salter, who is now married to one of her former boxing rivals, Lisa Holewyne.

Foster also offered effusive praise for his 27-year-old co-star.

"Sydney is a smokehouse. She's the real deal," he said. "She puts in the work. I think you all will be mind-blown by what she does in this film."

F.Criscuolo--INP