The 12-year-old, who has a rare metabolic condition that caused her to gain 151 lbs. and left her constantly hungry, no longer needs insulin or other medication to control type 2 diabetes.
"There was no sign of her diabetes 24 hours after the surgery," her surgeon, Dr. Thomas Inge of the Cincinnati Children's Hospital Medical Center, tells NBC News.
Shapiro's story gained attention earlier this year when her insurance company refused to pay for weight-loss surgery to treat her hypothalamic obesity, which she developed after having brain surgery two years ago.
That prompted an online crowd-funding campaign that raised more than $86,000 to help cover her surgery expenses.
On March 21, after some complications that forced doctors to change their plan to perform a gastric bypass, Shapiro underwent sleeve gastrectomy surgery, which removed about 80 percent of her stomach.
In addition to no longer needing diabetes medication, the surgery appears to have affected Shapiro's appetite.
"She can eat four or five bites now and have the feeling of fullness we all take for granted," Inge told NBC.
Shapiro, whose weight topped 200 lbs., was discharged from the hospital late Friday and will remain in Cincinnati for another week for close monitoring before returning home to Cibolo, Texas.
"It's really exciting stuff," says her mom, Jenny. "She's in much better spirits now being here at the hotel."
Her doctor is pleased with her progress so far and anticipates that Shapiro could stop gaining weight and lose about 40 lbs. in the next few months.