The Health Benefits of Bariatric Surgery Beyond Weight Loss – Are They Real?

Jeffrey I. Mechanick, MD, FACP, FACE, FACN, ECNU
The Health Benefits of Bariatric Surgery Beyond Weight Loss

Bariatric surgery is a term used to describe a number of operations that are used to cause weight loss in people with obesity. When these procedures were developed many decades ago, they were designed just for weight loss and were associated with many surgical and nonsurgical complications.

However, two major changes have occurred recently which change the way we think about bariatric surgery. First, the main procedures that are used – gastric bypass, sleeve gastrectomy and adjustable gastric band – are considered safe, especially in the hands of an experienced surgeon, at an experienced hospital, and when the benefits versus risks of surgery are reviewed for the specific person considering this surgery and the benefits clearly outweigh the risks.

Second, in the past few years, there has been better understanding as to the overall potential benefits of this surgery beyond just the obvious effect of losing weight. Specific to effects on blood sugars in the presence of diabetes mellitus, high blood pressure (hypertension), cholesterol and other conditions, there is now great interest about whether improving these conditions through surgery can have an impact on lowering the risk of future cardiac disease or improve the ability to live longer.

In order to better grasp this idea, let’s review some recent advances in the way we address obesity. In the past, obesity was considered to be a condition solely defined by an excess of body fat, determined by a body mass index (BMI) greater than 30 (see and treated with advice to eat less or go on a diet and exercise more. Nowadays, with the benefit of growing scientific research and clinical trial information, obesity is thought of as a more complex disease, involving nearly every part of the body, associated with many “obesity- related complications,” and managed using preventive strategies and many more options and approaches that can help in targeting weight loss and specific complications. Obesity-related complications include insulin resistance, a condition where there is insulin present, but it does not work as well as it should; type 2 diabetes, the diabetes which is a combination of the insulin present not working as well as it should, plus less than normal production of insulin; hypertension; high cholesterol and triglycerides (the major form of fat stored by the body in fat cells); heart and circulatory problems; depression; arthritis; stomach acid reflux; sleep apnea; and many others.

We have many tools now, including more structured lifestyle approaches (healthy eating, physical activity, sleep hygiene and behavioral medicine), new medications and, of course, safe and effective bariatric surgical procedures. In short, obesity as a complex disease can be approached in many different ways and should not be managed simply with one intervention, but rather with many interventions strategically fitting a person’s individual problems and needs.

Before describing the benefits of bariatric surgery, we must first look at the appropriate time to consider bariatric surgery. According to many professional medical guidelines, and especially considering the American Association of Clinical Endocrinologists’ (AACE) perspective on obesity care, lifestyle counseling should be initiated and maintained for all Americans, regardless of weight or other treatments, due to our constant exposure to an environment that is associated with obesity—keep in mind that two-thirds of all Americans are overweight or obese—a staggering number that is not being corrected nearly as fast as we would like. Depending on the presence and severity of obesity-related complications, a person with overweight or obesity may also need obesity medication or bariatric surgery. Your endocrinologist will be able to guide you through these decisions.

So what are the benefits of bariatric surgery? First and foremost, there is sustained and significant weight loss in many people, which may be seen long after the actual surgery is performed. Weight loss after bariatric surgery is usually expressed as a percentage of the excess weight lost and generally ranges from 30 to 70 percent at 10 years, depending on the procedure and other individual factors. Since weight loss can plateau after a number of years, continuation of lifestyle changes, possibly with more aggressive attention to changing lifestyle, must occur.

Obesity-related complications are generally related to weight; therefore the surgically induced weight loss can be associated with improvement in these obesity-related complications. In fact, as little as three percent weight loss with lifestyle changes can be associated with a reduction in risk for metabolic and cardiovascular disease, compared with bariatric surgery weight loss figures well over 30 percent. Patients with type 2 diabetes have actually been found to be in remission (off all diabetes medications with a target A1c, average blood sugar level, over two to three months of 6.5 percent or less for at least a year), with reports as high as 70 to 90 percent of the time. Although these improvement percentages might diminish over the following years, as physicians are now learning with longer follow-up of those with diabetes, there is active research into whether this improvement— either shorter or longer-term—can have a beneficial effect on cardiac disease risk, which is so high in those with diabetes. Remission rates of 40 to 80 percent are also seen for hypertension, high cholesterol and/or triglycerides, sleep apnea and depression.

Even though many of these obesity-related complications improve, many others may not reach targets. Thus, continued follow-up with a doctor experienced in the care of patients with obesity is strongly recommended. These follow-up visits focus not only on the physical examination and measuring blood pressure, weight and body fat changes, but also blood tests for cholesterol, triglycerides, blood sugar and electrolytes, liver and kidney function, A1c blood counts and, depending on the specific bariatric procedure, specialized testing for nutrients, bone function and other markers for potential complications of surgery.

Overall, bariatric surgery patients can live longer and healthier lives, but again, this is based on being properly selected for surgery, having an experienced surgeon and hospital and continuing to practice a healthy lifestyle, as well as engaging an expert such as an endocrinologist in postoperative obesity, nutrition and metabolic care. From an endocrinologist’s standpoint, there is a remarkable surge of interest in optimizing obesity care, spanning better education of physicians and other healthcare professionals, scientific research and clinical trials of new or improved therapies, a greater focus on prevention, and accelerating the use of structured lifestyle interventions. This is indeed an exciting time for all of us to become healthier, and a successful comprehensive approach to obesity, one that includes all people and their individualities, can make that a reality.

Weight-Loss surgery Guide

Gastric bypass surgery contributes to weight loss in two main ways: either by restriction, in which surgery is used to physically limit the amount of food a stomach can hold, or malabsorption, where surgery is used to shorten or bypass part of the small intestine, thereby reducing the amount of calories and nutrients the body absorbs.

Deciding to get weight loss surgery isn't an easy decision, and choosing a specific surgical approach will require a lot of thought and discussion with your physician. Here's some basic information to get you started.


Roux-en-Y gastric bypass is the most common type of weight loss surgery. It combines both restrictive and malabsorptive approaches and can be performed as either a minimally invasive (laparoscopic) or open surgery. In the operation, the surgeon divides the stomach into two parts, sealing off the upper section from the lower. The surgeon then connects the upper stomach directly to the lower section of the small intestine, essentially creating a shortcut for the food, which bypasses a section of the stomach and the small intestine. Skipping these parts of the digestive tract means that fewer calories get absorbed into the body. With Roux-en-Y gastric bypass surgery, weight loss typically is rapid and dramatic. But, while this type of surgery causes rapid weight loss, it also puts the patient at risk of significant nutritional deficiencies, requiring diligent monitoring of diet and the need for supplements for the rest of the patient’s life. Gastric bypass is generally considered to be irreversible.


Sleeve gastrectomy is another form of restrictive weight loss surgery. In the operation, which is usually done with a laparoscope [lap-ah-rah-skop], a slender, tubular camera used to examine body cavities during certain types of surgery, about 75 percent of the stomach is removed. What remains of the stomach is a narrow tube or sleeve, which connects to the intestines. Sleeve gastrectomy is often used with people who are very obese or sick, since it is a simpler operation that is a lower-risk way to lose weight. Because the intestines aren't affected, a sleeve gastrectomy doesn't affect the absorption of food, so nutritional deficiencies are not a problem.


Gastric banding is among the least-invasive weight loss treatments. In this surgery, an inflatable band is used to squeeze the stomach into a smaller upper pouch and a larger lower section. The two sections are still connected, but the channel between them is very small, which slows down the emptying of the upper pouch, physically restricting the amount of food you can take in at a meal. Gastric banding is simpler to perform, recovery is usually faster than other procedures and it can be reversed by surgical removal of the band. However, weight loss from gastric banding is often less than that from more invasive surgeries.

Dr. Jeffrey I. Mechanick Is Clinical Professor of Medicine and Director of Metabolic Support in the Division of Endocrinology, Diabetes and Bone Disease at the Icahn School of Medicine at Mount Sinai Hospital in New York City. He has authored over 170 publications in endocrinology and nutrition and edited/authored five books in the fields of diabetes, nutrition, thyroid and metabolic bone disease. Dr. Mechanick is in private practice in endocrinology and metabolic/nutrition support in New York City. He is Immediate Past President of the American Association of Clinical Endocrinologists (AACE).