AceShowbiz -

Mariah Carey's famous curvy body is surely a good thing, but things seemingly don't look good for the singer's health. A source says that the "All I Want for Christmas Is You" songstress has gone extremely overboard with her eating habits and even risks serious health issues.

Radar Online reports that the diva has packed on so much weight to the point that she is now having trouble walking. The 48-year-old reportedly had to be carried on and off stage during her July 11 concert at Caesars Palace. She also had to take long breaks during her 19-song set and went as far as having her handlers wheel her on to the stage.

"Every time Mariah came back on stage, she'd be carried in on a bed or on a jet ski," reveals an eyewitness. "She was obviously lip-syncing, and she kept disappearing for 15 minutes at a time under the guise of costume changes."

The source adds that the mother-of-two is "miserable." The source continues, "She wore five-inch heels during the show, but she couldn't walk more than a few inches at time, and her knees seemed to buckle under her weight. Whenever she stood up or moved, everyone held their breath for fear she'd fall."

Renowned dietician Dr. Stuart Fischer, who never treated the star, reveals that the bloated singer may be facing crippling arthritis and a string of life-threatening health woes. "Excess weight is a risk factor for osteoarthtitis of hips, and there are 65 illnesses--including heart disease, high blood pressure, diabetes and three cancers--that can result from obesity and affect women," he explains.

Mariah's eating habits are not helping either as she uses foods as means to comfort herself. "She's so fat that all her costumes keep having to be let out. She's bloated and uncomfortable, and doesn't have the stamina to perform anymore," the source dishes. "Mariah needs to take stock of her life-and sort it out in a hurry."