Disease of Obesity and Weight Regain

The Disease of Obesity & Weight Regain After Bariatric Surgery

July 22, 2020

In discussing obesity and weight regain after bariatric surgery, it is necessary to review some definitions and admit that our understanding of the chronicity of the disease of obesity continues to be a challenging and an incompletely understood topic before offering some solutions to this problem.

Common Terms for Obesity and Used in Bariatric Surgery

First, the definitions:
BMI, Body mass index: Calculated by dividing a person’s weight in kilograms divided by their height in meters squared. It is much easier calculated from readily available tables.
Overweight: BMI-25-29.9
Obese: BMI 30-39.9
Morbid obesity: BMI 40-49.9 (or BMI as low as 35-39.9 with medical co-morbidities.
Super morbid obesity: BMI 50-59.9
Super-super morbid obesity BMI 60 ad higher

Currently, someone would need to be in categories 4-6 to qualify for bariatric surgery in the US.

Measuring Weight Loss and Obesity

Weight loss after bariatric surgery has not been measured solely by the pounds loss but as a percentage of excess body weight (%EBWL). Excess body weight is the amount of weight above the individual’s ideal body weight (IBW) that is an abstract number derived from insurance actuarial tables for each person according to their height.

Another rough definition of morbid obesity would be if someone were 100 pounds over his or her ideal body weight. Therefore losing 50 pounds after surgery would be 50% EBW lost. If the person weighed 250 pounds and their IBW were 150 this would amount to 50 pounds lost.

Success after bariatric surgery strictly in terms of weight loss has been defined as “good” if 50% EBWL or a BMI of less than 35 was achieved and “excellent” if 75% or greater EBWL or a BMI < 30 was achieved. This obviously would be very difficult if not impossible of people in the highest BMI categories of 50 and above. So starting with reasonable expectations is important.

Unfortunately, even something as simple as measuring weight loss is confounded by the fact that most non-surgeons working in the weight loss field measure weight loss as a percentage of total body weight (%TBW). For example, to qualify for weight loss medication one would need a BMI of 30 or greater or a BMI of 27 with medical co-morbidities.

Success is now considered between 5-10% of TBW. So, the same person with a starting body weight of 250 would be considered successful if they lost 12.5-25 pounds even though the weight loss is just half of what that same person could expect after bariatric surgery (50 pounds).

Expected Range for the Various Surgeries

Now that we’ve defined what success in terms of weight loss means, there is an expected range for the various operations.

For purely restrictive operations such as Lap-Band and Sleeve Gastrectomy, the range has been 33-66%EBWL (33-66 pounds if you’re 100 pounds over IDBW). For Gastric Bypass, the range is 50-75% EBWL which is likely the same for Single Anastomosis Duodenal Interposition. For Duodenal Switch the range is reported as 70-100% EBWL.

I have always told prospective patient that in terms of weight loss alone, if they can attain and maintain a 50% EBWK after surgery that would be the average and a good result. I always warn the patients in the higher BMI categories (50 or greater) that this is more difficult because they have much more excess weight to begin with.

So, now you’ve had surgery and the weight has melted off that first year but in years 2-5, it has become more of a struggle and the weight is creeping back. Is that a problem? Some weight regain is a natural phenomenon having to do with your body’s adaptation to a lower calorie intake by dropping its basal metabolic rate (number of calories simply required for you to stay alive).

This needs to be moderated, not by simply trying to decrease your calorie intake, which is counterproductive if you’re eating a reasonable restricted calorie diet already (1200-1500 calories per day), but by increasing your calorie expenditure through exercise. The most common form of exercise that people who are most successful in maintaining weight loss perform is walking.

What is a “normal” amount of weight regain in years 2-5? Of course, that varies between individuals and depends as well on how much overall weight one has lost, but 5% TBW is likely the average (10 pounds given the example that we started with of a 250 pound person losing 50 pounds after surgery and experiencing a 5% weight regain long term so that now they weigh 210 instead of their immediate post op weight of 200).

Long-Term Weight Loss Results & Weight Regain

OK, but I’ve gained nearly all of my weight back. Is that because my operation has failed? This depends on the operation and how compliant you have been with diet and exercise.

Unfortunately, long-term weight loss results after Lap-Band have been disappointing and many are being converted to one of the other operations. It is still debatable whether this is solely attributable to the device or maladaptive eating and lack of exercise by the patient.

Eating soft fats and carbs (ice cream, cake, candy, cookies, pretzels, etc.) can undo any purely restrictive operation. Certainly, GERD (gastroesophageal reflux) unrelated to weight loss has been a great reason for Lap-Band failure as well.

So, what do you do if you are noticing that your weight is coming back? First and foremost, the old adage of an ounce of prevention is worth a pound of cure is very appropriate here. So, don’t wait until more than that 5% (10 pounds) has come back before making an appointment with your bariatric specialist and reentering the program.

Reestablishing your diet with the help of a dietician and engaging in a structured and doable exercise program are the cornerstones to long-term weight loss maintenance.

In addition, my personal approach has been to evaluate the primary bariatric operation with an upper GI and see if there are structural problems. If structural problems do exist or symptoms such as GERD with Lap-Band and Sleeve have become unmanageable, then revision or conversion surgery would be indicated.

Certainly, the super morbidly obese patient may simply need the malabsorption of the bypass or the duodenal switch to achieve success after a purely restrictive operation such as sleeve but I have found that staging the operations has many advantages.

The real problem is a gastric bypass patient with a structurally intact operation and yet significant weight regain. I currently do not reverse and convert to duodenal switch simply because that is a daunting operation with a high chance of complications and not necessarily tremendous outcomes.

The Addition of Weight Loss Drugs & Weight Regain

For any patient that is experiencing weight regain long term after surgery (or inadequate weight loss), I have found that the addition of weight-loss drugs has been extremely beneficial. Starting anorectics early before significant weight regain has occurred with the resultant 5-10 %TBWL (10-20 pounds in our example patient) has often allowed my patients to reset their early postoperative baseline and has kept them in our program.

The bottom line is preventing weight regain after bariatric surgery by continuing to follow up with your bariatric specialist and support group is the most effective strategy to remain successful. Paying attention and seeking treatment for even small amounts of late weight regain early is as important.

Never being embarrassed or hesitant to seek follow up care even if significant amount of weight regain has occurred. Morbid obesity is an incurable disease that must be followed for the rest of the patient’s life and a comprehensive center offering diet, exercise, medical and surgical approaches to long term weight regain is the way to go.

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Dr. Onopchenko MD, MBA, FACS, FASMBS is the founder & Medical Director of the Center for Surgical Weight Loss & Wellness at AtlantiCare since 2002, a Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) accredited Center of Excellence. He has extensive experience performing all laparoscopic bariatric surgery types such as Sleeve Gastrectomy, Roux-en-Y Gastric Bypass, Duodenal Switch, SADI & revision surgeries. Dr. Onopchenko is a member of the American Society of Bariatric Physicians.