Christina Aguilera was "struggling" with her weight last year, despite saying she was confident with her curves.
The stunning songstress showed off her slimmed down figure in a candy pink minidress at an event in Los Angeles last week.
Christina has reportedly lost over 2st in three months after sporting a curvy UK size 12 figure for the past couple of years.
"Christina's thrilled she'd regained the slender [UK] size 6 figure she had in her 20s," a source told British magazine Closer.
"Despite what Christina said at the time, she was struggling with her body - she's only 5ft 1 so feels comfortable when she's smaller - but she tried not to let it ruin her confidence and wanted to rise above the criticism. She found it hard to look in the mirror at times."
Christina gained her curves after splitting from Jordan Bratman in 2010 and has struggled with her yo-yoing weight since.
Last year the blonde star claimed she loved her frame, gushing: "The challenge I've always had is being too thin, so I love that now I have a booty and obviously I love showing my cleavage. My boyfriend [Matthew Rutler] loves my body."
Sources say Christina was motivated to lose weight after watching herself as a judge and mentor on the US series of The Voice earlier this year.
"She was a size 10 when she began The Voice but despite being a healthy size, she hated how she looked when she watched it back and broke down sobbing," the insider explained.
"The next day, she cleared out any 'bad foods' and called her trainer Tee Sorge and said she wanted to be a size 6 in three months."
Christina has also reportedly given up alcohol and has embarked on a fitness regime consisting of high-intensity cardio, and interval and resistance training.
"She's thrilled with the results," the pal smiled.
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