The Interface between Eating Disorders and Bariatric Surgery

In this article, we will review the literature on the relationship between disordered eating, eating disorders, and bariatric surgery. In particular, we will focus on:(1) binge eating and binge eating disorder (BED) in bariatric surgery patients; (2) the impact of binge eating and BED before and after surgery on the outcome of surgery; (3) the night eating syndrome (NES) and “grazing” in bariatric surgery patients; and (4) the development of eating disorders after bariatric surgery.

Aberrant Eating Behavior and Bariatric Surgery Outcome

Binge eating and full syndromal BED.It is now widely recognized that binge eating and full syndromal BED are common among obese persons seeking bariatric surgery. A number of research groups have studied whether binge eating and full syndromal BED might represent a relative contraindication to bariatric surgery or whether it might predict a poorer outcome in subjects undergoing various kinds of bariatric surgery procedures. Thirty-two studies have addressed the rates of binge eating or BED, either at baseline prior to surgery or at follow-up after surgery. The methodologies and instruments used have varied dramatically, as have the findings.

Rates for binge eating have varied from 6% to 64% and for BED have ranged from 1% to 49% before surgery. At follow-up, postsurgical rates of binge eating have varied from 0% to 71% and for BED from 0% to 32%, reflecting the markedly divergent methods that have been used to ascertain these phenomena.

One possibility that has surfaced repeatedly in this literature is that the presence of binge eating or BED presurgically might predict lack of weight loss, or greater weight regain after surgery. The studies that have evaluated this possibility are shown in Table 1.

As can be seen, only 2 out of 9 studies found that preoperative binge eating or BED predicted lack of weight loss or weight regain. However, of the 8 studies that examined whether the emergence or reemergence of binge eating, BED, or “loss of control” eating, after surgery was associated with weight outcomes, all found an association of such problems with less weight loss or with more weight regain. Also, the patients who developed these problems were almost exclusively those with binge-eating or BED prior to surgery. Further addressing a possible relationship between BE/BED and lack of weight loss or weight regain in this population, and establishing predictors of this outcome, might lead to the development of preventative interventions. Also of note are data suggesting that patients who binge-eat or report “out-of-control” eating after surgery have more psychopathology, depression, and alcohol dependence, as well as less weight loss.

Night eating syndrome. Another disorder of relevance to this application is the night eating syndrome. The concept of the night eating syndrome (NES) is in a state of transition. The original criteria by Stunkard et al. in 1955 that included evening hyperphagia, insomnia, morning anorexia, and feeling tense, upset, or anxious as bedtime nears have been modified several times, making this literature difficult to compare and summarize. However, research does suggest that NES is associated with psychological problems, and that there is overlap with BED. There is also possible overlap with another syndrome, Sleep-Related Eating Disorder (SRED).This syndrome is characterized by partial arousal from sleep, which is associated with eating, a reduced level of awareness, reduced level of recall, and at times ingestion of inedible substances. A variety of other sleep disorders have been described in association with this, including restless legs syndrome and somnambulism.

NES in bariatric surgery patients has been studied by several investigators. Powers et al., Kuldau and Rand, Adami, et al., Allison et al., and Rein et al. reported presurgical NES prevalence rates from 8% to 20%. Studies using retrospective recall have generally reported higher prevalence figures for preoperative NES of 33%, 42%, and 31%.

Only three studies have examined postsurgical rates of NES in bariatric surgery patients. Hsu et al. reported NES in 3 of 27 patients (11%) two or more years following gastric bypass. Another study reported full NES in only 1 of 160 patients who had received RYGBP Roux-en-Y gastric bypass (RYGBP) a year earlier, but subthreshold symptoms occurred in a much larger proportion. Hsu et al. reported that 2 of 10 patients (out of a total of 24 patients studied) who indicated a history of presurgical night eating returned to night eating, one at 12 months and one at 18 months post-surgery. In this study, the presence of any eating disturbance, including BED, NES, or excessive high-calorie fluid drinking, was associated with weight regain. Colles et al. reviewed the literature on NES in bariatric patients and stressed that many different definitions have been used, making the literature difficult to interpret.

Another eating problem that may emerge after bariatric surgery is “grazing,” a not-well-defined construct wherein patients eat small amounts of food over long periods of time. Another apparently uncommon, but unfortunate outcome, is the development of clinically significant eating disorders such as anorexia nervosa (AN) and bulimia nervosa (BN). Reports in the literature are summarized in Table 2 (page 8). Also of note, a patient with BN pre-surgery was found to be self-adjusting her band post-surgery in order to binge eat.

Effects of Bariatric Surgery on Eating-Related Behaviors

A few studies have examined the effects of various bariatric surgery procedures on eating behavior. Most of these studies have relied on available questionnaires or developed something new specifically for this purpose. Kenler et al. found that post- patients reported lower intakes of sweet-tasting substances, milk and ice cream, and high-calorie liquids than did post-gastroplasty patients after surgery. Cook and Edwards in 1999 reported that patients who successfully lost weight following gastric bypass could be characterized as having an eating pattern including eating three balanced meals a day with two snacks. Devlin et al. in 1997 reported that patients’ status post-RYGBP reported a number of changes in their eating behavior and in particular indicated that they could eat markedly less food “before feeling full,” and that there were certain foods that they no longer consumed. Hörchner et al. in 2002 reported a study of subjects’ status after gastric banding and found decreased emotional eating as well as decreased “external” eating after surgery. Lang et al. in 2002 also reported that patients’ status post-lap band surgery reported decreased hunger and decreased disinhibition in their eating. All of these studies are limited, however, by retrospective methods to assess eating behavior.

Two other studies are of interest concerning vomiting behavior. Busetto et al. studied patients’ status post adjustable gastric banding and found that those who met criteria for BED prior to surgery were more likely to have problems with vomiting and to develop neostoma stenosis postoperatively. Another study suggested that some individuals with a history of binge eating switched to “grazing” or snacking continuously over a long period, as a problematic eating behavior postoperatively.

Summary

It is clear from this review that disordered eating and eating disorders can proceed, re-emerge, or develop after bariatric surgery. It also appears that such problems may have a negative impact on surgery outcome. Eating disorder professionals who work with bariatric patients need to be aware of these issues. In addition to gathering additional data, the next step for research in this area is to study possible interventions for these patients to minimize such problems and maximize weight loss and other positive surgical outcomes.