NBC News - A week after long-awaited obesity surgery, a Texas girl with a rare metabolic problem that left her starving but gaining weight is out of the hospital and already meeting critical health milestones, doctors said.

Alexis Shapiro, 12, no longer needs insulin or other medication to control type 2 diabetes and she's feeling signs of fullness when she eats, rather than the insatiable hunger that drove her to top 200 pounds on her 4-foot-7 frame.

Both are the immediate results of sleeve gastrectomy weight-loss surgery, a procedure aimed at halting her massive weight gain and improving life-threatening health problems, said Dr. Thomas Inge, the pediatric obesity expert at Cincinnati Children's Hospital Medical Center who has led her care.

"There was no sign of her diabetes 24 hours after the surgery," Inge said. "My guess is she will not need insulin or anything else at this point."

Alexis was discharged from Cincinnati Children's late Friday, a week after the March 21 surgery. The Cibolo, Texas, girl drew international attention earlier this year after NBC News first reported that insurers were refusing to pay for doctor-recommended weight-loss surgery to treat hypothalamic obesity, a rare condition that developed after Alexis had brain surgery two years ago.

She'll remain in Cincinnati under close monitoring for about another week with her parents, Jenny and Ian Shapiro, who have two other children staying with family back home.

"It's really exciting stuff," said Jenny Shapiro. "She's in much better spirits now being here at the hotel."

The sleeve gastrectomy surgery, which removed about 80 percent of Alexis' stomach, reversed the diabetes by immediately affecting glucose metabolism, or the process of converting sugar into energy for cells to use. The procedure likely boosts production of anti-diabetic hormones from the lower portion of the gut and changes the processing of nutrients that act as metabolic signals.

At the same time, the surgery also appears to have affected Alexis' appetite, kicking in key signals that indicate satiety, or a feeling of fullness. Her diet has been limited to protein drinks and soft foods like special protein-enhanced puddings and yogurt, typically 4 to 5 teaspoons at a time, Inge said. After 3 teaspoons, Alexis is saying she's getting full.

"Some part of the brain is still switched on and is listening to these cues," Inge said.

Alexis is likely also losing weight, although doctors won't be able to judge how much for about another week, when her fluids rebalance after surgery. Inge anticipated that Alexis could stop gaining weight and lose perhaps 20 percent of her body mass, or about 40 pounds, in the early months after surgery, even as she gets taller.

Inge originally had planned to perform a different weight-loss operation, gastric bypass surgery, but discovered during surgery that her liver was much larger than expected, which forced a change in plans.

It's all good news for the child who was a normal 9-year-old before she developed a rare benign brain tumor. Surgery successfully removed the tumor, but it sent her metabolism haywire, Inge said.

Her story prompted interest from media outlets around the world and prompted strangers to donate more than $85,000 for her care. Inge said he's very pleased at Alexis' progress — and at the attention she's generated for other people with rare, medically induced obesity.

"This one particular patient is doing well, but her message is being heard all over the globe," Inge told NBC News. "Maybe it will get more medical attention now because of this one girl with her very private battle that became a public battle."