Incredible Shrinking Xtina! Christina Aguilera Losing Baby Weight ‘At A Rapid Pace’

Less than two months after giving birth to her daughter, Christina Aguilera has lost a whopping 15 pounds and she’s not through yet, RadarOnline.com has exclusively learned.

A source says, “She’s losing weight at a rapid pace and will have lost all of the 35 pounds she gained during pregnancy within a matter of weeks.”

As RadarOnline.com readers know, Aguilera, 33, gave birth to a baby girl by fiancé Matthew Rutler, 29, on August 16. They named her Summer Rain Rutler.

Since then, the “Beautiful” singer and frequent The Voice judge has been keeping a low profile as she raises her new child. She also has a 6-year-old son, Max, by ex-husband Jordan Bratman.

But during her break from The Voice, Aguilera has also been following a disciplined body after baby program, the source tells RadarOnline.com.

“Christina looks incredible. She’s breastfeeding, which takes away all of that bloat, and is consuming only around 1,600 calories a day. It would be even less, but she has to have an extra 500 calories to breastfeed,” the source notes.

“She’s doing a lot of yoga, meditation, treadmill, boxing and working out with her personal trainer.”

Aguilera has been like a yo yo with weight loss in the past. As  RadarOnline.com reported late last year,  she flaunted a slim new frame during a performance on The Voice with rapper Flo Rida.

“We’re finally reminded of what a small frame she actually has!” celebrity weight loss coach Alicia Hunter told RadarOnline.com at the time.