Approximately 160,000 stomach-reducing procedures of various types are performed each year. Gastric bypass, sometimes called stomach stapling, where surgeons shrink the stomach's size and reroute food to the small intestine, is the most common.
Gastric band surgery, best known by the brand name Lap-Band, is a less invasive and reversible alternative, in which an adjustable ring is placed over the top of the stomach and tightened to restrict how much food can enter.
Candidates for gastric banding must have a body mass index of between 30 and 40 — plus a weight-related medical condition, such as diabetes or high blood pressure — or a BMI of 40 and higher. They also must have previously attempted to lose weight through diet and exercise.
Christie, who says he does not have any other significant health problems, has talked about working with a personal trainer since he first ran for governor four years ago.
"If you eat appropriately and chew your food, it works nicely," said Dr. Christina Li, a bariatric doctor at Sinai Hospital of Baltimore.
She said Christie has the resources to have people help him eat right and get exercise. While the band is removable, she said patients are told to adjust to having it for the rest of their lives.
Li said risks include infection, and that it does not work for all patients.
Dr. Jaime Ponce, who practices in Dalton, Ga., and is president of the American Society for Metabolic & Bariatric Surgery, said people who have the procedure Christie had often lose 1 to 2 pounds per week.
Christie's procedure was performed by Dr. George Fielding, head of NYU Medical Center's Weight Management Program, who did the same procedure for New York Jets coach Rex Ryan three years ago.
"It basically teaches you how to eat like a human," Ryan said of the device in an interview last week with The Associated Press.