Obesity Subtype Can Affect Bariatric Surgery Results
Imagine if there was a tool that doctors could use to predict whether a patient would have an optimal outcome from bariatric surgery. A large analysis suggests that, depending on the subtype of obesity you have, weight loss outcomes of bariatric surgery will vary.
The research was presented at Obesity Week, a joint meeting of The Obesity Society and the American Society for Metabolic & Bariatric Surgery, and published in the November 2018 volume of Obesity. The researchers evaluated data from approximately 2500 people diagnosed with obesity, that participated in the Longitudinal Assessment of Bariatric Surgery (LABS) study. The focus was to see how patients with different subsets of obesity fared in weight loss after three years.
The four subtypes of obesity were identified as:
Comorbid diabetes with a low level of HDL (good cholesterol)
People with disordered eating (binge eating, bulimia, night eating syndrome)
Mixed obesity (more than one cause)
Early onset obesity
It’s important to acknowledge how difficult it is to lose a significant amount of weight and to then maintain that weight loss, essentially for life. Bariatric surgery has come to be considered an important tool in the treatment of obesity – not for everyone – but quite effective for some. Roux-en-Y gastric bypass approach has better success rates than gastric banding. But even Roux-en-Y has significant variability in long term weight loss outcomes.
Other variables that impact bariatric surgery success include the fact that some people do not understand the lifestyle choices they will need to follow post-surgery, how having a smaller stomach pouch can affect digestion, and the fact that food temptations and cravings may persist. This analysis suggests that certain subtypes of obesity are just not as well-matched to bariatric surgery for the treatment of obesity.
Understanding which subtypes match best allow for precision medicine, which in this case means optimizing outcomes by choosing the patients who best match to this treatment tool. According to the lead researcher, treating everyone with obesity “the same way,” especially when it comes to surgical options, may be hindering successful outcomes.
The researchers analyzed data accumulated during seven years post bariatric surgery. Patients completed written surveys that evaluated satisfaction with weight loss post-surgery, and researchers also examined reasons why the person ate, that excluded hunger through extensive questions. There were also questions about patterns of eating including binge behavior, cravings, feelings of loss of control with eating and other clinical markers that indicate disordered eating patterns.
Among the 2500 participants, 45 percent met criteria for “mixed type obesity.” The next most prevalent group was disordered eating (36 percent), followed by extreme obesity with early onset (15 percent). Obesity with diabetes/low HDL was the least common group (4 percent).
The group of early onset obesity had the highest BMI measurements prior to surgery, with higher BMI levels already by age 18. They also had the loftiest post-surgery BMI goal (around 26.5). The researchers noted that “eating when not hungry” was far more prevalent in certain obesity subtypes, while quite rare in other subtypes.
The true surprise finding was that at the three-year mark post Roux-en-Y surgery, the disordered eating subtype had the largest postoperative weight loss. Early onset obesity (both genders) lost 25-30 percent less weight in comparison, as did the obesity/diabetes subtype.
A major conclusion from the study was that people with early onset obesity need additional therapies to support any bariatric surgery choice. This would especially apply to supportive therapies that monitor and treat appetite behaviors, especially after the surgery.
Limitations of the study included the fact that most of the female participants were non-Hispanic white females. Hispanic and African American females have high rates of obesity and would benefit from a similar research-based evaluation. The study also did not include any evaluation of genetic influences on post-surgery weight loss, nor did it evaluate metabolic and physiologic factors that could influence weight loss after surgery.
From my perspective, the study highlights the need for all obesity subtype groups to get support before and after any bariatric surgery. The surgery itself can be life-changing IF the patient understands how their lifestyle has to change, in conjunction with this therapeutic option. That includes:
Stricter control of your home food environment
Working with a dietician or nutritionist to optimize weight loss by understanding how much food should be consumed at each feeding and the types of food you should be eating
A commitment to some type of physical activity most days of the week
Learning how to manage out-of-the-home food situations
Managing social and holiday food situations
Using other therapies like medication, psychological counseling
Maintaining a relationship with a support group
This research does seem to indicate that someone with serious, entrenched obesity from a young age may not have the kind of sustained weight loss that warrants “going through” major surgery. On the other hand, if you have gained significant weight due to disordered eating, then this research suggests that if other methods have failed, bariatric surgery may be a good option for you.
Doctors who specialize in obesity treatment and surgeons should certainly consider the information this research offers as they continue to evaluate the feasibility of bariatric surgery for particular patients.