Carol's surgeon, Dr. Don Whiting, says the goal of this operation is to help the brain's eating center find a healthier balance.

"Everybody knows people who have had heart pacemakers to have their heart work better," he says. "This is like a brain pacemaker that we hope changes the electric signals and the chemicals into the brain to give you a better metabolism."

Before this procedure becomes widely available, Dr. Whiting says he and his colleagues have to prove it's effective and safe. Then, he says, doctors may consider deep brain stimulation surgery when all else fails. "It would probably start out after bypass surgery, but it's a whole different approach," he says. "We're actually going to the control center, we think, to adjust things in a different way."