A binge by any other name: Objective vs. Subjective binge eating
It’s a question I’ve been asked many times: what, exactly, is a binge anyway? Is it eating too much? Eating a lot of food? What?
The DSM isn’t necessarily much more helpful. Take the new criteria for Binge Eating Disorder (via Mayo Clinic, as the APA pulled down the draft criteria from their website) that tries to define what constitutes a binge:
- Recurrent episodes of binge eating, including eating an abnormally large amount of food and feeling a lack of control over eating
- Binge eating that’s associated with at least three of these factors: eating rapidly; eating until you’re uncomfortably full; eating large amounts when you’re not hungry; eating alone out of embarrassment; or feeling disgusted, depressed or guilty after eating
So what does an “abnormal” amount of food mean? What about loss of control, or rapidly? How do you define that? Some people eat faster than others, and other people might eat more or less than you. It’s why there needs to be some flexibility in the definition, but, as it stands, it’s rather nebulous. In turn, what some people might call a binge, others might call having a second helping. In the research literature, you see this discrepancy accounted for by the use of the term objective or subjective binge eating.
In his directions for administering the Eating Disorder Examination, Fairburn gives the following directions about how to define a “large amount of food”:
Most of the studies I cite in this post use this definition of objective and subjective binges.
Generally speaking, the main difference between an objective binge and a subjective one is how much food is consumed. An objective binge meets the formal criteria described above: eating an abnormally large amount of food, typically in a short period of time. A subjective binge is when a person says they’ve binged, regardless of how much they’ve actually eaten. This, naturally brings up the question of how much people generally eat during a binge episode, which researchers have found most frequently lasts for two hours or less. In data compiled by Wolfe et al., the average amount eaten seems to vary fairly widely, but centers around ~2000 kcal, give or take.
In two different studies (Woell et al., 1989 and Rossiter & Agras, 1990), however, more than one-third of the people participating in the study said they binged when they had, in fact, consumed less than 500 calories. When it comes to defining a binge, it seems that the amount of food consumed doesn’t seem to be as large of a factor as the DSM diagnosis might have us think. To people with EDs who binge eat, a binge seems to incorporate one or more of the following:
- is the food consumed “forbidden” by the rules of the ED?
- does it place the person over the “acceptible” number of calories, etc, that they had allowed themselves to eat that day?
- what is the anticipated subsequent food intake?
- did they feel out of control while eating?
- did the eating violate any other personal or ED-related rules?
- was it part of a planned meal or snack?
Another reason to re-think the importance of binge size is its relationship with purging behaviors in BN.
A 2001 study by Keel et al. found that, while people with objective binge eating in BN purged more frequently than those with subjective binge eating, they also binged more frequently. Looking more closely at the data, there was a general correspondence between the number of binges with the number of purges. This seems to indicate that if someone with BN feels they have binged, they are likely to purge. When researchers looked at adolescents with BN (thus meeting the DSM criteria of objective binge eating) and those with EDNOS who endorsed purging behaviors, they couldn’t find any major clinical differences between the two groups (Binford & LeGrange, 2005). Both groups had similar BMIs and illness duration, and both groups reported significant levels of irregular periods. There was also no significant difference in the amount or types of purging methods used. The main difference was that the EDNOS group had lower levels of body dissatisfaction, eating and weight concerns.
A separate study found that using more than one method of purging was associated with increased frequencies of both objective and subjective binges, but they didn’t compare whether these frequencies differed (Edler, Haedt, & Keel, 2007). A 2005 study by these same three researchers found that people who only subjectively binge ate had fewer weekly binge episodes than those who objectively binge ate. They also purged less frequently, but it appeared to be consistent with less binge eating. This group also appeared to show lower levels of depression, anxiety, and ED psychopathology. My review of the existing studies didn’t find any research that indicated whether people were more or less likely to purge after a subjective binge.
A more recent study compared both the ED severity and overall psychopathology in people with BN who only objectively binged, only subjectively binged, or both (Brownstone et al., 2013). None of the three groups showed any differences between types of purging or frequency of purging, level of depression, and eating, weight, and shape concerns. When the researchers compared the groups that just objectively or subjectively binged, however, the objective binge eating group was more likely to purge by vomiting and less likely to use diuretics than the subjective group. As well, the subjective binge eating group had higher levels of impulsivity. The researchers explained these finding as due to
the distorted perception of having eaten a large amount of food during SBEs (subjective binge eating episodes) would likely be related to elevated cognitive distortion among the SBE-only group. Many of the cognitive distortion items relate to a sense of dissociation from reality. This component of cognitive distortion in relation to SBE-only presentations is perplexing, and warrants further investigation into the potential relation of dissociative experience to SBE occurrence.
Thus, part of the reason that there is not much of a practical difference between objective and subjective binges is that patients can’t always tell the difference since they’re so dissociated during the binge. There also doesn’t appear to be much significance between post-binge feelings of shame and guilt. The 2005 study by Edler, Haedt, and Keel also didn’t find any difference in the rates of recovery between ED sufferers who subjectively or objectively binged, at least during the 6 month follow-up.
Rather than focusing on the size of a binge as the important factor, perhaps the better question would be to ask whether a person felt a loss of control of whether, what, and how much they were eating. That seems to be the main defining factor of a binge, rather than a size. And since the formal criteria of an “objective” binge is ultimately subjective (based on what the patient reports on a questionnaire or to a therapist, or by the therapist’s own opinion), the distinction seems rather useless.