EDs Before and After Bariatric Surgery
What is bariatric surgery?
Bariatric surgery is an elective surgery that restricts the amount of food that can be ingested and/or absorbed. There are several types of bariatric procedures, including gastric bypass, sleeve gastrectomy, and the insertion of a gastric band or balloon.1
A main part of being successful after bariatric surgery is to follow the protocol provided by the bariatric team. This includes adherence to a very specific eating pattern, that ensures patients keep their bodies nourished and well fed while it undergoes drastic changes. The diet is restricted in several ways. First, the procedure leads to patients consuming a significantly smaller volume of food after surgery. Second, patients need to be focused on specific macronutrients and avoid certain foods that may trigger gastrointestinal upset. With that being said, patients cannot eat as freely as prior to surgery, which could make it challenging to eat intuitively.
When analyzing the correlation between eating disorders and bariatric surgery, there are still a lot of unknowns, making it hard to draw conclusions. First, the criteria used to identify eating disorders varies greatly between studies, including their definitions. Without consistent definitions, one study could diagnose eating behaviors as an ED, when the same behaviors may not be identified as an ED in another study. This makes it difficult to identify patterns and correlations between the existing evidence. In addition, there is limiting data on the prevalence of eating disorders after bariatric surgery. Much of the research is captured within the first year after surgery, which leads to conclusions that cannot be applied to the general post operative population.3 This understudied area of research also limits our ability to draw conclusions about the effects bariatric surgery can have on eating disorders overall.1 But to understand where the research is at now, we explain the patterns among specific eating disorders before and after bariatric surgery.
Binge Eating Disorder (BED)
Prior to surgery, Binge Eating Disorder (BED) is identified as the second most common psychiatric disorder in bariatric surgery patients, following major depressive disorder.2 The prevalence of BED among patients prior to surgery ranges from 4-49%.3 This wide range is likely due to the varying definitions and methods used to gather data. Some studies used self-reporting methods to identify BED in patients, while other studies used clinical interviews. The variation in gathering evidence makes it hard to understand how prevalent it is in patients that are getting bariatric surgeries.
With the change in anatomy of the digestive tract, behaviors seen in BED become physically limited. Patients are unable to eat large quantities of food in one sitting since the anatomy of the new stomach is physically stopping a binge. As time goes on, the prevalence of binge eating rises, usually seen 1-2 years after surgery. Because the size of the stomach is the reason for less quantity consumed, other behaviors are used to gauge the presence of BED such as loss of control while eating (LOC). If a person reports LOC while eating, regardless of the size of the meal, it can help clinicians detect the presence of BED.
Bulimia Nervosa (BN)
There is inconclusive evidence on the prevalence of Bulimia Nervosa (BN)
before and after surgery. This could be related to the underreporting of the behaviors in patients looking to get surgery, for fear of not qualifying for the procedure. There have been reports of BN after surgery, but the evidence is unclear. Part of this reason is because postoperative patients may induce vomiting to relieve uncomfortable physical symptoms after consuming intolerable foods. They also may induce vomiting if they ate too fast, and therefore too much for the stomach to hold. These reasons for induced vomiting, which are seen as suitable by the bariatric surgery team, make assessing the presence of an ED hard to identify in the studies.1
Anorexia Nervosa/Atypical Anorexia (AN)
Atypical Anorexia has been reported in patients prior to and after bariatric surgery. This is defined as people who meet the criteria for anorexia nervosa without objectively low weight.3 Patients following bariatric surgery have shown signs of: fear of weight gain (especially after rapid weight loss and hitting a plateau), restricted eating, and disturbances in body image, which are all behavior patterns of Anorexia Nervosa. However, other behaviors that typically are seen with AN are encouraged after bariatric surgery, making the presence of AN hard to identify. This includes limiting meal size, adherence to a specific eating schedule, weighing food, cutting food into small bites and chewing thoroughly, and avoidance of specific foods and food groups. These behaviors impact the success a patient has after surgery, which blur the lines of what can help diagnose AN in a postoperative patient.1
To conclude, at this point, the correlation between eating disorders before and after bariatric surgery is unclear. As the research moves forward, having clear screening and criteria to assess the presence of an eating disorder is crucial in both the preoperative and postoperative population. Knowing if a patient has an ED before undergoing surgery is extremely important and something that needs to be observed to assess if a person should be cleared for surgery. Having this information can help depict the success of the surgery given the restriction of the diet afterwards.
Sources:
Conceição, E. M., Utzinger, L. M., and Pisetsky, E. M. (2015) Eating Disorders and Problematic Eating Behaviours Before and After Bariatric Surgery: Characterization, Assessment and Association with Treatment Outcomes. Eur. Eat. Disorders Rev., 23: 417– 425. doi: 10.1002/erv.2397.
Dawes AJ, Maggard-Gibbons M, Maher AR, et al. Mental health conditions among patients seeking and undergoing bariatric surgery. JAMA. 2016;315(2):150. doi:10.1001/jama.2015.18118
Lauren Muhlheim PD. Eating disorders before and after bariatric surgery. Verywell Mind. https://www.verywellmind.com/eating-disorders-and-bariatric-surgery-4628329. Published May 1, 2020. Accessed October 27, 2022.
