The high prevalence of eating pathology prior to bariatric surgery reduces the likelihood of what researchers have termed “optimal” weight loss post surgery. However, such weight loss is in part due to post-surgical complications like “dumping” (rapid gastric emptying because digestive systems cannot process the food) or vomiting that can develop into conscious efforts to lose weight. Conceicao et al. (2013a) describe, for example, one patient who deliberately binged and purged on foods that would make her vomit spontaneously.
These kinds of results raise a number of questions:
- How prevalent are eating disorders (EDs) post-bariatric surgery?
- What are the risk factors for developing an ED?
- To what extent is the surgery itself a potential trigger?
PREVALENCE OF DISORDERED EATING AMONG INDIVIDUALS SEEKING BARIATRIC SURVERY
Researchers interested in bariatric surgery have explored how often those seeking bariatric surgery engage in disordered eating or have EDs. Prevalence rates vary between studies depending on what kind of behaviours researchers look for. For instance:
- Segal (2004) estimated ED prevalence among bariatric surgery patients as 2% for anorexia nervosa (AN) and bulimia nervosa (BN)
- de Zwaan (2007) found that 12% of bariatric surgery patients engaged in vomiting as a means of weight control
- The prevalence of binge eating disorder (BED) in particular appears to be higher than it is in the population as a whole, around 16% (Segal et al., 2004)
Some who receive bariatric surgery may end up seeking ED treatment after their surgery; for instance, Conceicao et al. (2013b) reported on 12 patients admitted for inpatient ED treatment within 4 years after surgery. Half of the patients in the study had medical complications after the surgery. While the study is very small, i is still an interesting result.
Conceicao et al. (2013) used DSM-V criteria to classify 6 patients as having AN, 2 as having BN, and 4 as having atypical AN-R. Most of them displayed classic ED symptoms: caloric restriction, fear of weight gain, and overvaluation of weight and shape. Some of them declined very quickly, with one patient being hospitalized only 3 months after surgery; the authors noted that the patient’s weight loss was perhaps exacerbated by medical complications after surgery.
Marino et al. (2012) also collated 22 studies examining the presence of EDs among individuals who have had bariatric surgery, suggesting that loss of control and grazing appear to be the most common features. However, they found that what stands out above all is the variability in how post-surgery EDs present. Part of this variation comes from the new “possibilities” for weight-loss behavior created by surgery–papers often made reference to physiological differences in the stomachs of bariatric surgery patients that force patients to get rid of their intake to relieve digestive discomfort.
RISK FACTORS FOR EDs AMONG BARIATRIC SURGERY PATIENTS
Are there particular factors that set people up to develop EDs after they have bariatric surgery? Conceicao et al. (2013b) reported that most of the patients they encountered who developed EDs had a history of dieting via laxative and diet pill abuse prior to surgery.
- 8 out of 12 patients had an ED diagnosis prior to surgery (including 1 with AN and 2 with BN, although it’s unclear if these diagnoses preceded a period of switching to bingeing behavior)
- 10 had family histories of mental illness
- 10 had a mood disorder diagnosis
- 5 had had prior psychiatric hospitalizations
These figures are exceptionally high because Conceicao studied fairly severe individuals who required hospitalization, but definitely points to the degree to which non-physical factors are entangled with the experience of obesity.
Lautenbach and colleagues (2013) provide a single case report in which doctors did not carry out a psychosocial evaluation before the surgery. This patient had other physical conditions that needed urgent treatment and surgery, which caused her treatment team to miss the red flag for her post-surgery relapse. Taylor and Sharma (2006) similarly report a case of BN that was not made known to the patient’s doctor, who told her how to adjust her lap-band size and inadvertently enabled bulimic behaviors.
The second main theme in terms of risk factors is that patients have trouble drawing the line between disordered and “normal” behaviors when the surgeries and the weight-loss counselling advice provided require them to engage in restrictive behavior. As Marino et al. (2012) note, “Routinely patients are instructed to limit meal size, to chew food extensively and to develop other eating patterns that could be regarded as ritualistic” (p. 181). One patient studied in Conceicao’s et al.’s (2013a) study drew a very clear causal relation to these instructions:
“The first month changed me; I was asked to weigh everything I ate and to be in control of everything I ate if I didn’t want to regain weight: the rules were too rigid.” (p. 277)
Segal et al. (2004) suggest that post-bariatric surgery EDs should be defined as a separate condition, “post-surgical eating avoidance disorder”, and proposes the following criteria for this:
- Faster than normal weight loss and abnormal laboratory testing
- Use of restriction and purging to reduce body image dissatisfaction
- Extreme anxiety or refusal to alter eating habits upon intervention
However, I wonder about the usefulness of delineating this kind of syndrome from normal eating avoidance behaviors after weight-loss surgery. As Natvik et al. (2014) note:
“Being mindless about eating was no longer an option for the participants. Nor was eating described as a deep and sensual experience, as it had previously been for some. Bariatric surgery was more like being sentenced to inescapable awareness of their habits, sensations, emotions, and thoughts.”
This “inescapable awareness” is reinforced by external guidelines and expectations of patients’ treatment teams, and in a sense might be considered iatrogenic to bariatric treatment. Any post-surgery follow-ups should include psychosocial evaluation and support should be involved, regardless of whether patients presented with existing EDs. We can’t ignore how the (increased) blurring of the line between normal and disordered eating requires patients to think about their food and body in very different ways, constantly negotiating the tension between “good” restriction (eating healthily for weight loss) and “bad” restriction (disordered eating for weight loss).
Conceição, E., Vaz, A., Bastos, A., Ramos, A., & Machado, P. (2013). The development of eating disorders after bariatric surgery. Eating Disorders, 21 (3), 275-282 DOI: 10.1080/10640266.2013.779193
Conceicao, E. et al. (2013b). Eating disorders after bariatric surgery: A case series. International Journal of Eating Disorders, 46, 274-9. DOI: 10.1002/eat.22074
DeZwaan, M., Georgiadou,E., Stroh, C.E., Teufel, M., Köhler, H., Tengle, M. & Müller, A. (2007). Body image and quality of life in patients with and without body contouring surgery following bariatric surgery: A comparison of pre- and post-surgery groups. Frontiers in Psychology, 5, 1310. DOI: 10.3389/fpsyg.2014.01310
Lautenbach, A. et al. (2013). 100 kg more or less, still the same person. International Journal of Eating Disorders, 46, 280-3. DOI: 10.1002/eat.22081
Marino, J. et al. (2012). The emergence of eating pathology after bariatric surgery. International Journal of Eating Disorders 45:179-184. DOI 10.1002/eat.20891
Natvik, E., Gjengedal, E., Moltu, C. & Råheim, M. (2014). Re-embodying eating: Patients’ experiences 5 years after bariatric surgery. Qualitative Health Research, 24(12), 700-10. doi: 10.1177/1049732314548687.
Segal, A. et al (2004). Post-surgery refusal to eat. Obesity Surgery 14:353-60. DOI: 10.1381/096089204322917882
Taylor, V. H., & Sharma, A.M. (2006). A patient with personal control of the adjustable gastric band and bulimia: A psychiatric complication. Obesity Surgery, 16(10), 1386-7. DOI: 10.1381/096089206778663751