Sydney Sweeney shared exactly what she ate to gain 35 pounds ahead of filming boxer biopic Christy. "It was a huge undertaking," she explained on Sirius XM on Wednesday, October 29. "The emotional toll of the span of [Christy's] lifetime, there's a lot of growth, and a lot of pain and a lot of understanding." She added, "The physical change that I also undertook was a lot." Sweeney shared that she had "about two and a half months to train leading up to it and [she] put on 35 pounds." "It was a lot of prep," she noted. "I was eating everything.