Long-Term Study Shows That Weight Loss Surgery Helps Lessen Risk Of Early Death From Certain Diseases


According to a study that was released by the American Obesity Association, by 2025, at least 50% of Americans will be obese, a number that will go to 60% by 2030.

Meanwhile, a new study from the Obesity journal has also shared that for people with severe obesity that decided to undergo bariatric surgery – or weight loss surgery – have found to be significantly less likely to die from diabetes, heart disease, or cancer as compared those in the same situation that chose not to have surgery.

Co-author of the study, Ted D. Adams, PhD, MPH, explained that what they found during a follow up 40 years after those that underwent surgery was that for those that went under the  knife, they saw their risk of premature death from any cause lessened by at least 16 percent as compared to those that didn’t get surgery. Dr. Adams is also a professor and researcher at the Intermountain Surgical Specialties-Digestive Health Clinical Program, as well as part of the department of nutrition and integrative physiology at the University of Utah located in Salt Lake City.

Dr. Adams says, “Additionally, the patients who had bariatric surgery had 29 percent, 43 percent, and 72 percent lower death rate from cardiovascular disease, cancer, and diabetes, respectively, when compared to the matched subjects who had not had bariatric surgery.”

The Effects of Bariatric Surgery Go Beyond Weight Loss

When it comes to bariatric surgery, it surgically alters the digestive system to better aid people in losing weight. As explained on the May Clinic website, there are also three major types of this surgery, and the two most common methods are sleeve gastrectomy and Roux-en-Y gastric bypass. For both surgeries, the surgeon will seal off or remove a part of the stomach, which in essence, limits the amount of food a person can eat at one time, also reducing the absorption of nutrients.

Usually, the stomach has the ability to hold around 3 pints of food. However, once gastric bypass is done, it becomes a much smaller sized food pouch with the ability to hold around 1 ounce instead.

As explained by weight loss surgeon at Duke Health in Durham, North Carolina, Dana Portenier, MD, bariatric surgery is considered a much safer and less invasive type of surgery these days as compared to the first ones that were done back in the 1950s. This is mostly because of the introduction of laparoscopic surgery, also known as keyhole surgery, which is a type of surgery that uses just small incisions and a camera. Notably, Dr. Portenier was not involved in the study.

Dr. Portenier explains, “We also eventually discovered that this surgery is just not shrinking the size of the stomach or how much food is absorbed. It’s also changing some of the hormones in the GI tract and this affects more things than weight, things like diabetes and metabolic syndrome.”

Meanwhile, according to the National Heart, Lung, and Blood Institute, a person is considered to have metabolic syndrome when they have three of the following conditions below:

  • A large waistline, or abdominal obesity
  • High blood pressure
  • High sugar levels
  • High blood triglycerides(a type of fat found in the blood that can raise LDL or “bad” cholesterol levels
  • Low HDL cholesterol(sometimes called “good” cholesterol)

“When metabolic syndrome is treated, we’ve found that people live longer and do better. Based on the evidence, the indication or recommendation on who may benefit from bariatric surgery has changed. It relies less on weight or BMI and more on whether the person has metabolic syndrome. As a result, some of the restrictions around weight are being dropped lower,” Portenier adds.

Usually Only Around 1 Percent of Those Eligible To Get The Surgery Will Get It

Dr. Portenier points out that currently, only around 1 percent of those people eligible to get this type of surgery will decide to get it. That’s only around 200,000 to 250,000 people per year within the United States. He adds, “The number of people choosing to have surgery has grown, but not as fast as the obesity rate.”

Moreover, according to the Centers for Disease Control and Prevention (CDC), ‘it’s estimated that 41.9 percent of adults in the United States have obesity today. Meanwhile, also observed by the CDC, around 20 years ago, it was also estimated that around 30 percent of Americans had obesity.

Study Findings Support the Bariatric Surgery Benefits 

In order to see how bariatric surgery can affect the risk of death, researchers matched 21,837 people into pairs as one who had surgery and one that did not. The subjects were also paired by age, sex, and body mass index (BMI). Then the mortality rates were compared and ranked according to sex, surgery type and the age of the patient at surgery.

Dr. Adams shares, “I believe our findings support the benefits of bariatric surgery. The results should also encourage future research to try and determine what changes are happening in the body due to bariatric surgery so that new nonsurgical treatments can be developed that have the same benefits.”

As for Dr. Portenier, he agreed, explaining, “Forty years of data — and keep in mind bariatric surgery 40 years ago was very different than it is now and had a much higher risk — shows that those who had surgery lived longer. That’s what we’re trying to do in most medical interventions: help people live longer and healthier lives.”

He also shared that the surgery has majorly reduced the risk of dying from the many other major diseases, such as diabetes, heart disease, and cancer.

Those Who Did Bariatric Surgery Were At a Higher Risk of Suicide

However, reseachers also found that death from suicide was substantially higher among those that did the surgery as compared to those that opted not to do the surgery. This was also see more in those between the ages of 18 to 34 years old.

According to the authors, these findings may show that the more aggressive, pre-surgical psychological screening and post-surgery follow-up may actually be very beneficial.

Dr. Portenier also says that the suicide risk findings is concerning and requires attention. However, it also aligns with former research. He explains, “When we look at surveys of people who are struggling with their weight and considering bariatric surgery, we do see a higher rate of depression and other mental health conditions, and the most common medications that people report taking are antidepressants,” he says.

He also points out that insurance companies and medical guidelines now require these healthcare providers to perform psychological evaluations of their patients up front before proceeding with the surgery.

“At Duke, we have embedded psychologists here at our weight loss clinic that work hand in hand with us. We have a team approach to ensure that people can access the support they need. What this study highlights is the need to continue that long-term mental health support after surgery, too,” he says.

An addition, there is a chance of an initial high or a “honeymoon stage” right after surgery since patient’s moods improve for a while. However, these feeling eventually wear off, while the normal, everyday trivialities of life seep back in, which is hard for some. He goes on to say, “There also needs to be more research about how bariatric surgery may impact the absorption of antidepressants or other medications people may be on for mood disorders. We need to make sure that a person’s depression is still being adequately managed.”

Surgery May Increase Risk of Death from Chronic Liver Disease

In addition, the study also discovered some evidence that suggests that bariatric surgery may lead to an increased risk of death from chronic liver disease.

Dr. Portenier points out that obesity is fast becoming one of the leading causes of patients requiring liver transplants in America, surprisingly surpassing alcohol misuse. He says, “We know that with fatty changes in the body, that leads to fatty deposits in the liver, which can lead to permanent changes. There’s a lot of evidence that suggests that bariatric surgery helps with liver disease. But in this study, that’s not what the authors found over the course of the follow-up.”

“These findings don’t really match what we’ve seen in other research. Many hepatologists [who deal with diseases of the liver] are sending patients to bariatric surgery because of the benefits it can have for the liver. It could be that in the long-term, that might not always be the case. I think the jury is still out on that,” adds Portenier.

Thankfully Bariatric Surgery Is Slowly Losing Its Stigma

Dr. Portenier adds, “I think the attitudes around weight loss surgery have evolved and it’s more accepted by the general population. Part of that is that it’s much safer than when it was first introduced.”

Regardless, there is still some enduring biases and misunderstandings when it comes to those with obesity. “People can see obesity as an individual failure rather than a real genetic disease process like high blood pressure or high cholesterol. But more and more people are beginning to recognize it for what it is — a disease process — and we’re slowly seeing attitudes change,” he says.

He also believes that more and more people should choose surgery to treat their issues with obesity and metabolic syndrome. He says, “I think a lot of that [reluctance to opt for surgery] has to do with the fact that we make it all about the weight in the United States, and there can be a stigma with that. In many countries, bariatric surgery is considered surgery for diabetes or for metabolic syndrome, which emphasizes that the surgery is to treat a disease, rather than just a way to drop weight.”

New Guidelines For Weight Loss Surgery

In October 2022, the National Institutes of Health (NIH) released new guidelines for weight loss surgery, the first since 30 years ago.

In the former 1991 NIH consensus statement, it said that bariatric surgery was just for those with a BMI of at least 40, or a BMI of 35 with at least one or more obesity-related conditions, like heart disease or hypertension.

As for the newly updated guides, which were developed by the American Society for Metabolic and Bariatric Surgery (ASMBS) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), it is now recommended that those with a BMI of 35 or those with a BMI of 30 to 24.9 for those with metabolic disease.

However, the guidelines also say that there need to be provisions and adjustments should be made depending on populations, such as Asians that should consider surgery at a beginning BMI of just 27.5.

Dr. Portenier iterates, “These recent guideline changes are a good step in the right direction so that people with metabolic syndrome can get what they need.”