Obesity Medicine Perspective on Metabolic/Bariatric Surgery

Updated: Dec 5, 2020

I was asked about my thoughts on bariatric surgery. It is a BIG topic, but here are some highlights! Please ask questions for follow up and remember, there are MANY different situations and things at play in each individual. So, these are starting points for a conversation with your physician, not medical advice!

WHO should consider bariatric surgery?

If you have a BMI over 35 with Type 2 Diabetes or other medical condition related to the disease of obesity, or a BMI over 40, then you should consider it. As always, a non surgical approach to a medical condition may be more prudent prior to a surgical approach, but this is not always the case. There are certain circumstances in which it makes sense to go straight to surgery in medicine. This tends to be when time is a factor, or non surgical treatment is not expected to have a high enough success rate.

What is Metabolic Surgery?

Metabolic surgery is surgery to treat the metabolic condition of Type 2 Diabetes Mellitus. Bariatric surgery is known for weight loss, but it also can reverse, prevent, or greatly improve Type 2 Diabetes. In certain cases, an individual may not have that much excess weight, and the primary treatment goal is to treat Type 2 Diabetes. The procedure that has the greatest effect on Type 2 Diabetes Mellitus is a gastric bypass, but a sleeve gastrectomy has a significant effect, as well.

How much WEIGHT do people lose with bariatric surgery?

Many people are surprised to hear that they are not expected to lose ALL the excess weight with bariatric surgery. The most common surgery done today is a sleeve gastrectomy. With this surgery, 60-70% of the excess weight is expected to be lost. This means that if the starting weight is 300 pounds, and a “goal weight” is 160 pounds, then 60-70% of 140 pounds, or 84-98 pounds, is expected to be lost. This makes the expected end weight to be 202-216 pounds, but not 160 pounds. Of course, these are averages. Some people lose MORE than the recommended weight, and end up underweight, and others have “incomplete” weight loss and lose less than 60% of the excess weight. We do not understand why these differences occur.

Will the weight STAY off?

This is one of the biggest surprises for many people, patients and physicians alike. Bariatric surgery is a relatively new treatment in the grand scheme of things. Very few people were getting the surgery for a long while, probably due to lack of insurance coverage, in part. It takes a certain critical number of people to have had the procedure and then a certain number of years to observe them after to adequately see what happens. We have not yet seen what happens to people as they age into their 70s and 80s. We are starting to see people who know a few people who have had the surgery and this is helping them form their opinions. So, what are we seeing? Well, the biggest thing is that 45% of people are experiencing weight regain, defined as regaining 25% or more of the weight they lost. So, there are people who have incomplete weight loss and then people who regain weight. I think that doctors and patients alike may have expected a surgical fix to be a definitive one, like removing a tumor. I think it is a testament to the strength of the metabolic adaptation to weight changes that weight gain occurs so often even after such drastic anatomy changes.

WHY does weight regain occur after bariatric surgery?

The absolutely true answer is, “We don’t know.” But, my opinion is that weight regain can happen no matter how a person loses weight due to metabolic adaptation, including a lower basal metabolic rate than expected for the weight loss, increased hunger and cravings, reduced satiety and satiation, a lowered metabolic rate due to weight loss, and potentially greater loss of skeletal muscle with bariatric surgery.

What are some of the SIMILARITIES and DIFFERENCES between medical and surgical weight loss?

When comparing an intensive, comprehensive, gold standard medical weight loss program directed by an obesity medicine physician, utilizing all the treatment tools available (not a casual diet!) some of the similarities include:

  • Rate of weight loss (but you can start the weight loss on your first visit with medical weight loss!)

  • Type 2 Diabetes remission and prevention

  • Long term weight loss as long as treatment is continued!

Some of the potential differences between medical and surgical weight loss are:

  • No anatomy change with medical weight loss. You CAN eat a normal meal anytime