The media mogul recalled the late comedian asking her, “Why are you so fat?” Oprah Winfrey recalled being publicly body-shamed by Joan Rivers, who made her weight topic No. 1 during Winfrey’s first appearance on “The Tonight Show” in 1985. On Monday’s episode of the “Jamie Kern Lima Show” podcast, the media mogul recalled how, despite being invited to talk about her then-booming TV …