A second source tells ET that Carey, who feels "much better about herself" now, adding, "this is a new beginning for her."
Carey's rep would not comment on her weight loss surgery. Page Six was first to report the news.
Another part of the singer's new beginning is wrapping up her Las Vegas residency at Caesars Palace and moving on to The Venetian in March 2018. According to the source, Carey has signed a "two-year deal contingent upon how well the show does in the first year."
When reached for comment, The Venetian Las Vegas would not confirm the news, telling ET they're "consistently engaged in discussions with a number of today’s top artists regarding residencies, and we are always interested in having artists of the caliber of Mariah Carey perform at our venues."