CHRISTINA AGUILERA is back in her prime after dropping more than 40 pounds, but some people fear the sexy songstress has gone overboard!

The “Dirrty” singer has been battling weight issues for the past few years, topping out at around 140, as The ENQUIRER previously reported. Christina has managed to shed all her excess flab and then some over the past year – and she now tips the scales at a wispy 100 pounds, according to sources. But her dra­matic weight loss has some fans concerned that she’s taken her extreme diet and exercise routine too far.

Christina stunned onlookers at the American Music Awards on Nov. 24 when she walked the red carpet in a breathtaking, itty-bitty Size 0 white gown that showed off her new physique. But the dress’ plunging neckline clearly revealed how bony and frail she’s become.

“Someone please give her a sandwich,” one Internet poster wrote under a photo of the 33-year-old, who just finished her latest stint on “The Voice.”

Another one noted: “(Christina) is very lovely, however I think she lost 10 pounds too much.”

A third summed things up by saying: “She overdid the weight loss. Once you can see the bones in a woman’s chest, she’s too thin.”