If you have a weight problem and have developed type 2 diabetes, you may be considering bariatric weight-loss surgery, which has the potential to cure—yes, cure—diabetes. This major surgery is a serious decision, and later on in this article, we’ll help you understand both the benefits and risks.

Of course, the old-fashioned way to lose weight if you have diabetes was to go on an intensive exercise-and-diet program and stick with it so that you lost a significant amount of weight on your own, without the pain, expense and risks of surgery.

According to the latest study, however, using lifestyle weight loss by itself to fight diabetes is very difficult. The new study sheds light on what a healthy lifestyle really can do to improve your health if you have diabetes—and what it can’t do.


In the study, researchers at University of Pittsburgh treated 61 obese patients with diabetes for three years. The age range was 25 to 55, mostly women and some men. The goal—remission of diabetes. It’s called remission rather than cure because it’s not known yet whether the reversal is permanent. However, it does mean that your blood sugar levels are normal or nearly normal and you can stop taking all of your medications.

During the first year, some of the participants got bariatric surgery—either gastric bypass or gastric banding. Gastric bypass permanently shrinks your stomach and also diverts food from some of the areas in your stomach and intestine so that you absorb fewer calories from what you eat. Gastric banding is a less invasive surgery (it’s also reversible) that shrinks your stomach so you feel full faster and therefore eat less food.

A third group went through an intensive lifestyle weight-loss program that included changes in diet and exercise, with frequent one-on-one sessions with a behavioral health coach plus regular group sessions for one year.

Everyone—both those who had surgery and those who lost weight without surgery—got regular support for years two and three to help them keep the weight off.


The lifestyle-only group improved their health status significantly…

• By the third year, they had lost and kept off 6% of their body weight, on average—going from 180 to 169 pounds, for example. They lost body fat, shrunk their waists, reduced LDL “bad” cholesterol and triglycerides, raised HDL “good” cholesterol and dropped their blood pressure readings.

• Blood sugar control improved a lot. Fasting blood sugar levels went down 28%, and A1c levels, a measure of long-term blood sugar control, also went down a bit. However, these improvements were not enough to reverse diabetes. Many subjects were able to reduce their medications but none was able to get off all medications.

In two measurements, the lifestyle group actually did better than the bariatric group—they lost less muscle mass and had almost no bone loss. Both are good things, as we’ll see in a bit.


Both bariatric surgery groups did much better on weight-loss and health measurements—and many went into diabetes remission…

• By the third year, the gastric banding group had lost 15% of their body weight, on average…had bigger drops in health factors like cholesterol and blood pressure…and saw their fasting blood sugar levels drop by 35%. A1c levels went down much more than with the lifestyle group, too. About 29% of the gastric banding group went into diabetes remission.

• The gastric bypass group did the best, losing, on average, 25% of their body weight, with similarly dramatic drops in other health measures. Fasting blood sugar levels went down 66%, and A1c levels went down too. About 40% of the gastric bypass group went into diabetes remission.

These surgeries start working to control your blood sugar and diabetes pretty much right away, not just after you’ve lost a significant amount of weight. “Within a week of bariatric surgery, many diabetic individuals have been able to go off or substantially reduce their medications for glucose control, yet the scale has only dropped maybe one or two pounds,” says Dale Hamilton, MD, an endocrinologist and diabetes researcher at Houston Methodist Hospital. “Their energy levels improve, and many of them feel like 10 years have come off their age.”

Scientists aren’t sure why, but the surgery appears to change many physiological processes well before the weight comes off. In addition to the mechanical effects, gastric bypass increases the secretion of intestinal hormones that control the feeling of fullness and improve the balance of bacteria in our guts that help us metabolize food. Banding doesn’t have as profound an effect on these factors, which may explain its less dramatic results.


Like any surgery, bariatric procedures come with short-term risks, but it’s the long-term risks that are more concerning. Short-term risks during and right after the procedure include bleeding, infection, leaking from the site where the intestines are sewn together, diarrhea, bowel blockage and blood clots. Banding tends to have fewer surgical complications than bypass.

In the long term, nutrients from foods aren’t absorbed as well, so you’ll need to take vitamin and mineral supplements. Hernias may also occur after either kind of surgery. People who have these procedures also tend to experience a loss of lean body mass (muscle) that’s out of proportion to their fat loss. Some patients experience bone loss and develop osteoporosis earlier than normal. Some patients also start producing too much insulin after bariatric surgery, which can cause hypoglycemia (low blood sugar). There is also a very small risk—about 1%—that the surgery can trigger emotional problems in some individuals, leading to self-harm and suicide risk.

This study followed the patients for three years after their surgery. That’s about as long as these kinds of studies last. Unfortunately it’s not known what happens to diabetes status—or other long-term benefits or risks—after that time frame.


Because of these and other lingering question marks, it would be unwise to suggest that everyone who is obese and has type 2 diabetes should get the surgery. According to Dr. Hamilton, you’re a good candidate for bariatric surgery if…

• You’ve had type 2 diabetes for less than five or 10 years and you’re having trouble controlling it with lifestyle changes and medication. If you’ve had diabetes for longer, your pancreas, which produces insulin, might not be able to recover even after surgery, so you would still need at least some medication. Your doctor can give you a blood test to gauge how well your pancreas is working, but in general, if you’re taking oral medication or only a low dose of insulin, you’re still a good candidate.

• You’re obese and your weight is contributing to other health conditions, such as joint, knee or lower-back problems…respiratory issues…heart disease…high blood pressure…high cholesterol…or sleep apnea. The surgery can help with all of these medical issues.

In some cases, bariatric surgery might even be worth considering if you’re prediabetic (showing signs of insulin resistance), obese and have weight-related health problems. “There’s very strong evidence that bariatric surgery can help prevent diabetes,” Dr. Hamilton says.


As with everything about your health, the choice is yours. For example, just because gastric bypass surgery had more dramatic benefits than gastric banding doesn’t mean that it’s a better choice for you. You may look at the banding procedure, the recovery time and the fact that it can be reversed in the future if there’s a serious complication, and decide that it’s a better choice for you.

No matter what choice you do make, you’ll need to commit yourself to healthier eating and exercise habits. That’s because lifestyle change is not only the key to preventing diabetes but is the foundation of effective treatment for diabetes—even if you have surgery.

After all, bariatric surgery will work in the long term only if you are seriously committed to a permanent change in your lifestyle. After you’ve lost a substantial amount of weight, it’s normal to gain back a little. But if you haven’t changed your eating and exercise habits, you can find ways to subvert the weight loss—milkshakes, anyone?—and undo the benefits.

One of the best benefits of bariatric surgery, says Dr. Hamilton, is that you’ll have more energy. This starts before you even lose a lot of weight, and it can help that process along if you take advantage of it by moving more. “After the surgery, patients start to walk more—they’ll walk up the stairs or, if they’re at the airport, instead of getting on the cart to take off to the terminal, they’ll walk,” Dr. Hamilton says. “Most patients, down the road, just feel better.