Behavior After Bariatric Surgery Key, Study Finds

Preoperative variables have been the focus of numerous bariatric surgery studies. Now a study looking at postoperative factors demonstrates that assessing weight management practices and eating behaviors after surgery, as well as problematic substance use, can significantly affect how much weight a patient loses.

James E. Mitchell, MD, from the University of North Dakota School of Medicine and Health Sciences, Grand Forks, and colleagues published the results of the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) study online April 20 in JAMA Surgery.

“In particular, the data suggest that developing positive changes in behavior, including ceasing negative behaviors or increasing positive behaviors, can affect the amount of weight loss,” the authors write.

To maximize the favorable effects of bariatric surgery in severely obese adults, it is essential to identify factors that are associated with successful weight loss after surgery. Therefore, the authors conducted a study to evaluate postoperative predictors of the amount of weight loss after bariatric surgery in severely obese adults.

The LABS-2 study included 2022 post–bariatric surgery patients, of whom 1513 had undergone Roux-en-Y gastric bypass (RYGB) and 509 had undergone laparoscopic adjustable gastric banding (LAGB). All participants were undergoing first-time bariatric surgery between March 2006 and April 2009, and were followed up until September 2012.

Surveys were conducted on participants before surgery and then annually after surgery for 3 years. The surveys examined 25 postoperative behaviors that are considered modifiable, including those related to eating behaviors and problems, weight loss practices, and problematic substance use.

The median age of study participants was 47 years, and the median body mass index was 46; 78% were women. Three years after bariatric surgery, the observed median percentage weight loss was 31.5% of baseline body weight for RYGB and 16.0% for LAGB.

Among participants who underwent RYGB, three behaviors explained most of the variability (16%) in weight change at 3-year follow-up. In particular, participants who self-weighed weekly, stopped eating when feeling full, and stopped eating continuously throughout the day lost an average of 38.8% of their baseline weight. This was about 14% more than participants who did not use these behaviors (mean, −24.6%; mean difference, −14.2%; 95% confidence interval [CI], −18.7% to −9.8%; P < .001), and 6% more than those who had always used these healthy behaviors (mean, −33.2%; mean difference, −5.7%; 95% CI, −7.8% to −3.5%; P < .001).

Dr Mitchell and colleagues note that similar results were obtained for LAGB. “The results of this study suggest that certain behaviors, many of which are modifiable, are associated with weight loss differences of significant impact in patients undergoing RYGB or LAGB. The magnitude of this difference is large and clinically meaningful,” they write. “In particular, the data suggest that developing positive changes in behavior, including ceasing negative behaviors or increasing positive behaviors, can affect the amount of weight loss.”

The authors therefore highlight the need for clinicians to target these behaviors in patients after they have undergone bariatric surgery. “[S]tructured programs to modify problematic eating behaviors and eating patterns following bariatric surgery should be evaluated as a method to improve weight outcomes among patients undergoing bariatric surgery,” they conclude.

In an accompanying editorial, Amir A. Ghaferi, MD, Marilyn Woodruff, MSN, ANP-BC, and Jenna Arnould, MS, RD, all from the VA Ann Arbor Healthcare System in Michigan, emphasize that “bariatric surgery providers should seek better methods for longitudinal management.”

However, they also point out the difficulty faced by providers as they try to differentiate the effects of patient behavior from hormonal or genetic factors that may contribute to decreased weight loss after bariatric surgery.

“Currently, we owe it to our patients to provide an infrastructure to maximize adherence to best practices, while taking care to avoid applying a one-size-fits-all approach,” they conclude.

This study was supported by a cooperative agreement funded by the National Institute of Diabetes and Digestive and Kidney Diseases, with grants for the data coordinating center, Columbia University Medical Center (in collaboration with Cornell University Medical Center Clinical and Translational Research Center), University of Washington (in collaboration with the Diabetes Training Research Center), Neuropsychiatric Research Institute, East Carolina University, University of Pittsburgh Medical Center (in collaboration with Clinical Trials Research Services), and Oregon Health and Science University. The authors have disclosed no relevant financial relationships. Dr Ghaferi reported receiving research funding from the Agency for Healthcare Research and Quality, the National Institute of Aging, and the Patient Centered Outcomes Research Institute and receiving salary support from Blue Cross Blue Shield of Michigan as the director of the Michigan Bariatric Surgery Collaborative. The other editorialists have disclosed no relevant financial relationships.

JAMA Surg. Published online April 20, 2016. Article abstract, Editorial extract

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