On the Efficacy of Self-Induced Vomiting (Purging)

A single in-lab assessment of caloric consumption, loss, and retention during binge-purge episodes in individuals with bulimia nervosa (BN) is frequently cited as evidence that purging via self-induced vomiting is an ineffective strategy for calorie disposal and weight control (Kaye, Weltzin, Hsu, McConaha, & Bolton, 1993). These findings have been widely interpreted to mean that, on average, purging  rids the body of only about half of the calories consumed, regardless of total quantity.

However, a closer examination of the study does NOT support the notion that purging is an ineffective compensatory behavior. Indeed, the findings of Kaye et al. (1993) would appear to have been both misunderstood and overgeneralized in the subsequent decades. This has important implications for therapeutic alliance in clinical practice as well as for understanding the nature of symptoms, metabolic processes, and physiological alterations in EDs.


The study included 17 individuals, all of … Continue reading →

HW vs. CW: Weight Suppression in Bulimia Nervosa – Part I

HW. CW. LW. GW1. GW2. GW3. UGW.

If you have (or have had) an eating disorder (or dieted and used online forums), chances are you know what those acronyms mean. And if you have browsed blogs written by eating disorder sufferers, chances are you have come across these acronyms too. After all, they are a prominent feature of many such blogs.

If you are lost, I’ll fill you in: the acronyms stand for Highest Weight, Current Weight, Lowest Weight, Goal Weight 1/2/3, and Ultimate Goal Weight (UGW). Unsurprisingly, most individuals with eating disorders, much like dieters, like to keep track of their weight loss — that is, the difference between the highest weight, HW, and the current weight, CW.

Researchers call this difference weight suppression (WSmore specifically, the highest adult body weight) and one’s current weight). It … Continue reading →

Posttraumatic Stress Disorder in Women with Bulimia Nervosa

Posttraumatic stress disorder (PTSD) is 3-5 times more prevalent in individuals with bulimia nervosa (BN) than those without (Dansky et al., 1997). However, the relationship between PTSD and BN–in particular, how PTSD might affect or moderate bulimic symptoms–remains largely unexplored. In a recent study, Trisha Karr and colleagues followed 119 women (20 with PTSD and BN, and 99 with BN only) for a 2 week period to investigate whether participants with comorbid PTSD + BN differed from those with BN only on the:

  1. Levels of negative affect (negative emotional state/mood) and affect variability (fluctuation between negative and positive states)
  2. Frequency of bulimic behaviours
  3. Relationship between emotional states (negative or positive affect) and bulimic behaviours

They used the ecological momentary assessment (EMA) tool to track behaviours and emotional states close to when they occurI’ve blogged about a study using EMA before (‘What’s The Point of Bingeing/Purging? And Why Continue reading →

Bingeing and Purging: Keeping the “Positives” and Eliminating The Negatives?

I have been fascinated and perplexed by reports of the seemingly invigorating and anxiety reducing effects of bingeing and purging (purging by self-induced vomiting). Personally, I cringe at the idea of self-induced vomiting and have always wanted to avoid vomiting at all costs, including during food poisoning. The insight from recent blog entries and the subsequent comments has made an impact on me. I see that the motivation to engage in bingeing/purging behavior can be intense and can provide an effective way increase positive affect and reduce stress. The ameliorating effects of bingeing/purging remind me of drug addiction, with bingeing/purging behavior as the “drug.”  This made me wonder, what happens in the brain to impart such “addiction-like” reinforcement?

I know there are reports of opiate and endorphin release following purging, but to me, this seemed like an effect meant to counter the intense aversion (and discomfort?) of the … Continue reading →

What's The Point of Bingeing and Purging? And Why Can't You Just Stop?

I defended my MSc on Tuesday and I’m not going to lie: I was pretty symptomatic with bulimia in the days prior to my defence. As I explained to my boyfriend: the anxiety-reducing effects of purging are so powerful, and the compulsion to binge and purge (when I’m stressed/anxious/”not okay”) is so strong that it is much easier to do it, get it over with, and continue working (in a much calmer state).

I’ve mentioned before, for me, purging is very anxiety-reducing and in some ways, almost a positive experience. It is so tightly coupled with bingeing that it is hard to separate the two, but the anxiety-reducing effects are strongest when I binge and purge, non-existent when I binge, and weak when I purge a normal meal (which is exceptionally rare/almost never.)

It turns out, of course, that I’m not alone.

Negative emotional states and stressors have long been … Continue reading →

Bingeing and Purging Marathons: Repeated Binge/Purge Cycles in Bulimia Nervosa

I used to call them bingeing and purging marathons. If I binged and purged in the morning, chances were, I’d binge and purge throughout the day. The next time I’d eat, I was likely to end up–whether I wanted to or not–bingeing and purging. Not all individuals with bulimia nervosa binge and purge every day (or purge everything they eat, for that matter), but many do, and some binge and purge multiple times a day. In recovery, many people start by trying not to binge and purge before a certain time of the day–because once they binge and purge, it triggers a continuous cycle of bingeing and purging until they become to exhausted or otherwise end up going to bed.

I always wondered why that was, why was it so hard to keep a single episode of bingeing and purging from initiating a repeated cycle of bingeing and purging?

On … Continue reading →

Serotonin Function in Bulimia Nervosa – Brain Circuits & Behaviour

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter that is involved in just about everything. It helps ensure proper cell growth, maturation and migration during development. Serotonin is also important in regulating emotions, cognitive functions, appetite, pain, circadian rhythms, and our endocrine system in adulthood. It is hardly a surprise then, that the serotonergic system seems to be important in bulimia nervosa (BN).

I’ve written previously about serotonin in restricting-type anorexia nervosa, so for this post I’m going to be shifting focus and talk about bulimia and binge-purge type anorexia nervosa (AN-BP).

The information in this post isn’t coming from a review paper. Instead, I’m going to be summarizing and explaining information from a chapter in a book titled Behavioural Neurobiology of Eating Disorders. In the chapter on serotonin and bulimia, Howard Steiger and colleagues propose a model for serotonin action in bulimia nervosa which takes into account “diverse Continue reading →

Impulsivity in Eating Disorders is Associated with Bingeing/Purging

There is a marshmallow in front of you. Can you wait for twenty minutes, starring intently at the white, soft, cylindrical shaped sweet, to get another marshmallow? Or do you devour it right away, forgoing the opportunity to have two sweets?

I’d probably wait. But that’s only because I don’t like marshmallows, and would be in no rush to consume either one or two of them. What about you?

That’s the famous experiment that’s shown to many first year psychology undergrads (I, too, watched videos of little kids anxious waiting for 20 minutes, or not, in my first year psych class). It was designed to measure delayed gratification, in other words, are you able to wait, to get a reward, to delay gratification?

Leah recently asked whether studies have looked at delayed gratification in eating disorder patients. What I loved about her comment is that she included a hypothesis: … Continue reading →