Bariatric Surgery and Devices for Weight Loss

Reviewed by: HU Medical Review Board | Last reviewed: December 2023

Bariatric surgery is a medical procedure designed to help people with severe obesity lose weight and improve their overall health. Bariatric surgery is also known as weight loss surgery.1-3

This type of surgery has greatly advanced in the last few decades. Bariatric surgery is a major operation and should be carefully considered by you and your healthcare team.1-3

Why is bariatric surgery performed?

Bariatric surgery is used to treat severe obesity. But it also can address certain obesity-related health problems like type 2 diabetes, metabolic disease, high blood pressure, sleep apnea, and joint problems. It is generally considered only when other weight loss methods – such as diet, exercise, and prescription drugs – have not worked.1-4

How does bariatric surgery work?

Bariatric surgery works by making changes to the gastrointestinal (GI) system. Depending on the type of procedure, it either restricts the amount of food the stomach can hold or reduces nutrient absorption.1-3

This leads to:1-3

  • Reduced food intake, resulting in weight loss
  • Increased feeling of fullness (satiety)
  • Reduction in ghrelin, the hunger hormone

Who should consider bariatric surgery?

There are specific criteria that you must meet to be a candidate for bariatric surgery. Bariatric surgery is recommended for adults who:1,3-5

  • Have a body mass index (BMI) of 35 or higher
  • Have a BMI of 30 or higher along with obesity-related health issues like type 2 diabetes
  • Have a BMI of 30 or higher and have tried other weight loss methods without success
  • Meet the above criteria and are committed to making long-term lifestyle changes

Bariatric surgery may be considered for children and adolescents who:4,5

  • Have a BMI greater than 140 percent of the 95th percentile (class 3 obesity)
  • Have a BMI greater than 120 percent of the 95th percentile (class 2 obesity) and other obesity-related health problems

If you are a candidate for bariatric surgery, you will have a thorough evaluation to make sure you are physically and mentally prepared for the procedure. For any child who is being considered for bariatric surgery, they must be evaluated by a multidisciplinary healthcare team first.1,3-5

What are the benefits and risks?

It is important to be aware of all the benefits and risks that come with choosing bariatric surgery or devices.1,3


Bariatric surgery has benefits that extend beyond weight loss. It can help with obesity-related conditions like:1,3

  • Heart disease
  • High blood pressure (hypertension)
  • High blood sugar
  • High cholesterol
  • Non-alcoholic fatty liver disease
  • Sleep apnea
  • Type 2 diabetes


Bariatric surgery is largely considered safe. But, as with any major operation, there are still some risks involved. Initial risks from the surgery can include:1,2

  • Adverse reactions to anesthesia
  • Bleeding
  • Blood clots
  • Breathing problems
  • Infection
  • GI complications
  • In rare cases, death

Long-term risks and complications may involve:1

  • Acid reflux
  • Dumping syndrome – a condition that causes diarrhea, flushing, dizziness, nausea, or vomiting
  • Gallstones
  • Hernias
  • Malnutrition
  • Low blood sugar (hypoglycemia)

In some cases, more procedures may be needed to fix any problems that arise after surgery.1

These are not all the possible risks of bariatric surgery. Talk to your doctor about what to expect with bariatric surgery. You also should call your doctor if you have any changes that concern you after your procedure.1

Types of bariatric procedures and devices

Several bariatric procedures and devices are available. They each have their own benefits. Most of them are laparoscopic procedures. These are minimally invasive procedures that use small incisions and specialized tools, such as robotic surgery. These methods have proven to be very safe and provide faster recovery for patients.2

The most common surgeries and devices include the following.

Gastric bypass

This procedure involves creating a smaller stomach pouch and rerouting the digestive tract to bypass a portion of the small intestine. It restricts food intake and reduces calorie absorption.1-3,6

Sleeve gastrectomy or gastric sleeve

Here, the surgeon removes a large portion of the stomach, leaving behind a smaller, banana-shaped sleeve. This limits food intake and reduces hunger cues.1-3,6

Adjustable gastric band

In this surgery, a silicone band is placed around the upper part of the stomach. This creates a smaller pouch. The band can be adjusted to control food intake.1-3,6

Biliopancreatic diversion with duodenal switch (BPD/DS)

This procedure is similar to a gastric bypass. But it limits food consumption to a greater degree. The surgeon removes a large portion of the stomach, reroutes the intestines, and limits food absorption. This greatly impacts hunger and fullness hormones.1-3,6

Stomach intestinal pylorus sparing surgery (SIPS)

This is a newer procedure and is a modified version of the original duodenal switch procedure. It still reduces the size of the stomach, but it bypasses less of the small intestine. This leads to better nutrient absorption.3

Intragastric balloon

Here, a deflated balloon is inserted into the stomach through an endoscopic procedure. Once inside, the balloon is filled with saline solution to occupy space in the stomach. This helps you feel full faster and eat less. The balloon remains in the stomach for around 6 months. It is then removed.7

AspireAssist device

With this device, a tube is surgically placed in the stomach. This allows you to drain a portion of your stomach contents after each meal, which helps to reduce calorie absorption.8

vBloc therapy

An implanted device delivers electrical pulses to the vagus nerve. This large nerve controls feelings of hunger and fullness. Stimulating it with electrical pulses can help you eat less.9

Who performs bariatric procedures?

Bariatric surgery requires several medical specialists. Your bariatric surgery team may consist of:1,6

  • Bariatric surgeon
  • Anesthesiologist
  • Registered nurse
  • Registered dietitian (RD)
  • Psychologist
  • Other healthcare professionals

Make sure you choose an experienced and accredited surgical team. This will ensure the best outcomes and reduce your risk of complications.

What to expect and how to prepare

Before the surgery, your healthcare team will give you a series of medical tests and evaluations to assess your overall health. You will also follow a special diet in the days leading up to the procedure. You may also be asked to stop taking certain medicines. Tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.6

The surgery is performed under general anesthesia. This means you are asleep during the surgery. It can take several hours to complete.6

After the surgery, you will be closely monitored by your medical team. You may stay in the hospital for a few days to make sure you are recovering well. During this time, you will need to follow a special diet. Recovery times vary from several weeks to several months. It depends on the person and the procedure.1,6

You will then have frequent follow-up medical visits to check how you are healing, your overall health, and your weight loss results. You must commit to major lifestyle changes. This means eating a modified diet, getting regular exercise, and making sure you are getting adequate nutrition. Talk with a dietitian to make sure you are eating a balanced diet.6

Other things to know

Bariatric surgery is not a quick fix or a standalone solution. It requires a lifelong commitment to dietary changes, physical activity, and regular follow-up appointments.6

Your healthcare professional will tell you which foods and drinks you can consume, and which ones to avoid.6

After bariatric surgery, some people find that seeing a counselor or therapist can help with psychological and emotional issues that contribute to their weight change.4

Talk with your doctor

Bariatric surgery can offer hope to those living with severe obesity. It can provide an effective tool for significant weight loss and can help improve other areas of a person’s health beyond obesity.

While it offers many benefits, you must carefully consider the potential risks and long-term changes. If you believe bariatric surgery may be right for you, talk with your doctor. They can refer you to a bariatric surgeon who can discuss options that might work for you.

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