Curvy Christina Aguilera May Have Destroyed Her Metabolism With Yo-Yo Dieting

WENN

Even though Christina Aguileras weight has been steadily increasing over recent months, fans were still shocked at the Grammy Award winning singers appearance when she performed at the Michael Jackson tribute concert in Wales on Saturday.

Squeezed into a skimpy corset and fishnet tights, the 5'1 1/2" singer seemed completely oblivious about the considerable curves she has added to her once svelte figure.

"She is totally unaware of how she looks, no one dresses like that unless they think they look good," nutritionist Jackie Keller, CEO of Nutrifit in Los Angeles, told RadarOnline.com in an exclusive interview.

As RadarOnline.com previously reported, Christina's unflattering outfit and wild, unkept hair brought gasps from the crowd when she took the stage.

Keller went on to explain that because Christina, who is rumored to have suffered from an eating disorder in her teens, has gained and lost so much weight over the years it has distorted both her self-perception and her metabolism.

"Even if it was years ago, if she did suffer from an eating disorder then the effect of that stays with you and causes a distorted body image," she revealed, adding that the physical side affects are just as extreme as the emotional ones. "Yo! yo-ing in weight completely throws off your metabolism, which is why it is important to feed your body properly."

Aguilera has admitted to being a junk food addict when she was younger, which adds to the problems of trying to maintain a steady weight.

"Going through periods of eating really bad food and then not eating is a form of binging calling 'disordered eating,' which destroys the metabolism because you are always at a war with food," explained Keller, who provides calorie-controlled delivery meals to some of Hollywood's hottest stars.

Now the Beautiful singer's weight gain has steam-rolled to the point where she doesn't even seem to be aware of it.

"When you start gaining it cascades and just piles on and on," said Keller. "You only see what you want in the mirror, its the same as with anorexia. You only see yourself from the neck up and are unaware of how under or over-weight you are."

After messing up how she processes food at a young age, 30-year-old Aguilera's alcohol consumption could also be emphasizing her weight issue.

"If she is drinking as much as people say she is, then she just needs to stop, as that would immediately change her bodys metabolism," Keller said definitively, explaining that the body deals with the calories from alcohol first, and then stores all the additional food calories in favor of processing them.

"People dont have any clue how bad excessive calories are from alcohol. Stopping drinking would make an enormous difference in her b! ody, and then she can go on to whittle away her other bad habits one by one, such as cutting out processed food and exercising," she explained.

The 5' 1 1/2" pop star appears to be around 150 pounds, estimated Keller, who thinks that 100 to 110 pounds is a healthy weight for her.