But what Rubino considers obvious, some experts consider controversial. Medicine is an art that requires a delicate balance of risks and benefits, and gastric bypass surgery is a grueling procedure that carries major risks. Patients can die during surgery or develop serious complications, and the recovery is long and painful. Post-op, patients have to radically cut down on their food intake to accommodate the new tininess of their stomachs. The dramatic rerouting of the intestines and shrinking of the stomach may cause persistent long-term problems, such as malnutrition and bone loss, and some patients suffer severe depression. In addition, little is known about how diabetics who are only slightly overweight will respond to the surgery.

An Early Adapter
Some people aren’t waiting for all the answers to come in. Chris Iaboni, who lives just outside New Haven, Connecticut, was in her late thirties when she learned she had type 2 diabetes. Over the next eight years, she followed her doctor’s advice, took her medicine and watched her diet but was never able to control her blood sugar. The medications she took made her weak and nauseated, and even after insulin was added to her regimen, her diabetes progressed. Her feet began to tingle, a sign of possible nerve damage.

Trolling the Internet for information that might help her, Iaboni learned about Rubino’s efforts to reverse diabetes through bariatric surgery and started e-mailing him to see if she might be a candidate. Since she was five feet five inches tall and weighed 195 pounds, with a BMI of 32.4, she wasn’t obese enough to qualify for health insurance coverage, so she and her husband scraped together $30,000 to pay for the operation themselves.

“My doctors told me this was excessive and too aggressive,” she recalls. “But they had tried just about everything on me, and nothing seemed to work. I didn’t want to just try to manage the diabetes—I wanted a cure.”

And that’s what she got. Within a week of her gastric bypass surgery, Iaboni’s blood sugar levels normalized. An implanted glucose monitor that tracked her sugar levels continuously for five days showed they were all within the normal range, and within a few months she was able to stop taking medications. Almost a year later, she is still diabetes free. Her blood pressure and cholesterol have also dropped, and as a bonus, she has lost 50 pounds.

Why Does Surgery Help?
A new study from Columbia University suggests bariatric surgery improves diabetes better than if patients simply lost an equivalent amount of weight by dieting. What’s going on? Nobody knows for sure, but scientists think the mechanical reconfiguration of the stomach and intestines during surgery leads to a surge in several key hormones, especially one called glucagon-like peptide-1. GLP-1 is released during digestion and is produced in higher amounts after bariatric surgery, possibly because food passes to the end of the small intestine so quickly. This hormone nudges the pancreas to make insulin at just the right times, when blood sugar is high, and it tamps down the liver’s production of glucose.

GLP-1 is also a satiety hormone, which may explain another interesting side effect: After surgery, people can eat a meal and feel as if they’ve had enough food, often for the first time in their lives. Many formerly obese people say that before they had the operation, they never really knew how it felt to be full unless they had gorged themselves until they were, as one patient put it, “Thanksgiving Day full.” The surgery veterans can now experience the sensation of satiety and stop eating—almost as though a long-broken gas gauge has finally been fixed.