How Weight Loss Surgery Helps Type 2 Diabetes

Medically Reviewed by Sabrina Felson, MD on May 06, 2021

Weight loss surgery can make a big difference for people with type 2 diabetes. For some people, blood sugar levels get back to normal after surgery. Diabetes can be cured.That could mean you need less medication or none at all.

Research shows improvements in type 2 diabetes after weight loss surgery. One long-term study tracked 400 people with type 2 diabetes. Six years after bariatric surgery, 62% showed no signs of diabetes. They also had better blood pressure, cholesterol, and triglyceride levels.

In comparison, only 6% to 8% of people who took medicine, but didn’t have surgery, showed similar results.

If you’re thinking about it, and you’re ready to make big changes to keep up the results, you’ll want to know if it’s right for you.

Are You a Good Candidate?

First, your doctor will consider:

  1. Is your BMI 30 or higher?
  2. Do you have diabtes type 2 or metabolic syndrome?
  3. Have you tried to lose weight and keep it off without success?

If so, they will give you a detailed checkup and ask you questions to see if you are physically and emotionally ready for the operation and the major changes you'll need to make. (You'll need to eat a lot less and make a healthy diet and exercise part of your life forever.)

Depending on your particular case, other doctors may also get involved. For instance, if you have heart disease, your cardiologist would need to approve you for surgery.

Types of Weight Loss Surgery

There are different kinds of operations. Some help you lose weight by shrinking the size of your stomach so you feel full after small meals. Others change the way your body absorbs calories, nutrients, and vitamins. Still others do both.

Get to know what’s involved with each of these:

1. Gastric bypass (also called Roux-en-Y gastric bypass)

The surgeon makes a small stomach pouch by dividing the top of the stomach from the rest of it. When you eat, food goes to the small pouch and bypasses the top of the small intestine. The result: You get full faster and absorb fewer calories and nutrients.

Pros: Up to 80% of people show no signs of diabetes after surgery. Plus, people usually lose 60% to 80% of their extra weight.

Cons: Your body can’t absorb as many vitamins and minerals as before, which could lead to health problems, including a condition called dumping syndrome. Also, the surgery is not reversible.

2. Gastric sleeve (also called sleeve gastrectomy)

The surgeon removes a large part of your stomach. With less room for food, you feel full faster. This operation also lowers ghrelin, the hormone that makes you feel hungry.

Pros: More than 60% of people show no signs of diabetes after surgery. Plus, people usually lose 50% of their extra weight. It is also done laparoscopically.

Cons: You can't get this surgery reversed later on. Also, your body can’t absorb as many vitamins and minerals as before, which could lead to health problems.

3. Adjustable gastric band

The surgeon puts an inflatable band around the top of the stomach. It forms a small pouch where the food goes. The tiny pouch fills up fast, so you feel full a lot quicker.

Pros: Your doctor doesn’t have to cut the stomach or move the intestines, like in other surgeries. That’s one reason it has fewer complications. Also, you can get the band adjusted or taken out later. Forty-five percent to 60% percent of people who have this surgery end up diabetes-free.

Cons: Sometimes there are problems with the band. It may slip or become worn, so you could need another surgery to fix it. Also, you’ll lose less weight with this surgery than others (about 40% to 50%).

Another type of gastric banding operation, called "vertical gastric banding," isn't done as much as in the past because there are newer, more effective options.

4. Biliopancreatic diversion with a duodenal switch

This surgery is not common, partly because it’s the most complicated. The doctor removes a large part of the stomach and also changes the way food moves to the intestines.

Pros: It’s the most effective surgery for people with diabetes. Also, people usually lose 60% to 70% of their extra weight.

Cons: You're more likely to have complications with this type of surgery. You will need more days in the hospital to recover. Plus, you’ll have more trouble digesting food and absorbing calories than with any of the other surgeries, so it’s the most likely type to lead to health problems.

As with any major operation, all weight loss surgeries (also called “metabolic and bariatric surgeries”) have potential risks. These include bleeding, infection, and leaks in the digestive system.

5. Electric Implant Device

The surgeon implants an electrical device just beneath the skin of your abdomen. The device helps control signals in the vagus nerve which connects the stomach and the brain, reducing the feeling of hunger.

Pros: Implanting the device is considered minor surgery and it can easily be removed once weight loss is achieved. The device can also be controlled remotely.

Cons: Patients may experience pain, heartburn, problems swallowing, belching, nausea, and chest pain.

6. Gastric balloon

Gastric or intragastric balloons are temporary devices that are placed in the stomach via the mouth for up to 6 months. They help you lose weight by taking up space in the stomach. You can't eat as much.

Pros: The gastric balloon is an easy procedure, it is temporary, reversible, and it is less expensive than surgery. There is no cutting at all. It is inserted by endoscopy. Also, it is available for people who may not be eligible for weight loss surgery. 

Cons: There have been at least a dozen reported cases of stomach perforation because of the gastric balloon. Some patients have reported blue-green urine, a sign of balloon deflation. 

Will Insurance Cover It?

Many insurance companies do cover weight loss surgery, since studies show that weight loss surgery could help treat type 2 diabetes.

Your insurance company may ask you to go on a weight loss program first. This will show that you tried to lose the weight before choosing surgery.

If you don’t have coverage, the surgery can cost between $11,500 and $26,000. You can deduct it from your federal income taxes.

After Surgery

The best way to keep the weight off is to stick to your diet and exercise plan.

You’ll have to eat smaller meals. Choose a half-cup to a cup of vegetables and protein-rich foods per serving. Try lean cuts of meat, fish, beans, low-fat cheese, and yogurt.

It's a good idea to work with a nutritionist as you shift your eating habits, especially if your body doesn't absorb nutrients as well as it did before your surgery. Make sure you get enough of all the vitamins and minerals you need.

After you lose a lot of weight, you may want to consider plastic surgery to take up loose skin. That’s a separate procedure that you and your doctors can consider.

Show Sources


International Diabetes Foundation: "Bariatric Surgery: An IDF Statement For Obese Type 2 Diabetes."

American Society for Metabolic and Bariatric Surgery.

National Institute of Diabetes and Digestive and Kidney Diseases.

Mayo Clinic: Gastric Bypass Diet: “What to eat after surgery.”

Mayo Clinic: Gastric Bypass Surgery: “Risks.”

Loyola University Medicine: “Metabolic Surgery & Bariatric Care.”

Columbia University Irving Medical Center: "Gastric Balloons."


