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 →

I Need How Many Calories? Caloric Needs in Bulimia Nervosa Patients

In the 1980s, a few studies came out suggesting that patients with bulimia nervosa (BN) require fewer calories for weight maintenance than anorexia nervosa patients (e.g., Newman, Halmi, & Marchi, 1987) and healthy female controls (e.g., Gwirtsman et al., 1989).

Gwirtsman et al. (1989), after finding that patients with bulimia nervosa required few calories for weight maintenance than healthy volunteers, had these suggestions for clinicians:

When bulimic patients are induced to cease their binging and vomiting behavior, we suggest that physicians and dietitians prescribe a diet in which the caloric level is lower than might be expected. Our experience suggests that some patients will tend to gain weight if this is not done, especially when hospitalized. Because patients are often averse to any gain in body weight, this may lead to grave mistrust between patient and physician or dietitian.

Among many things, this ignores the fact … Continue reading →

Hypermetabolism in Anorexia Nervosa

Weight restoration is a crucial component of anorexia nervosa treatment. It is a challenging process for a multitude of reasons. Adding to the complexity and the challenge is the fact that during weight restoration, individuals with anorexia nervosa tend to require increasingly more calories to maintain the same rate of weight gain.

That is, individuals need to continually increase their caloric intake, in steps, sometimes upwards of 100 calories (technically, kilocalories) per kilogram per day, to continue gaining weight. For instance, an individual weighing 45 kg may need to eat 4,500+ calories to continue gaining 1-1.5kg (2.2-3.3lbs) a week. Indeed, studies have found that standard resting energy expenditure (REE) equations tend to overestimate caloric needs at the beginning of refeeding but underestimate them in the later stages (Forman-Hoffmann et al. 2006; Krahn et al., 1993).

After achieving a healthy weight, individuals recovering from anorexia nervosa still typically … Continue reading →

The Benefits of Starving – Part II (Restricting Reduces Anxiety in Anorexia Nervosa)

What is different about anorexia nervosa sufferers that, in contrast to most dieters, enables them to maintain a persistent calorie deficit? Although no one can truthfully claim they know the full answer to that question, we do know that part of the answer most likely lies with serotonin (5-HT), a molecule that neurons use to communicate with each other.

I’ve written about serotonin in the context of anorexia nervosa before, so I’ll just do a brief summary of the important points here:

  • Serotonin has a lot of functions in the body; it plays a role in regulating appetite (satiety), sleep, mood, behaviour, learning and memory, and a variety of other things
  • Serotonin has been implicated in obsessionality, harm avoidance, and behavioural inhibition
  • Alterations in serotonin function have been linked to many disorders, including depression, OCD, anxiety, and eating disorders
  • Serotonin is made from tryptophan, an essential
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Factors Associated with Recovery from Anorexia Nervosa

Why do some people recover anorexia nervosa relatively quickly while others seem to struggle for years or decades? Does it depend on the person’s desire to get better? Their willpower? How much they are willing to fight? Is it just that some try harder than others? Some might say yes, but most will correctly realize that the picture is much, much more complex.

We can spend hours talking about barriers to treatment, but in this post I want to talk about something slightly different, something perhaps that is perhaps less “obvious.”

Suppose a group of girls–all roughly the same age, same illness duration, same socioeconomic background and race–enter the same treatment facility. What determines why some will do well in treatment and continue to do well after discharge, whereas others will relapse immediately after discharge, and yet others won’t respond to treatment at all? We know that catching eating … Continue reading →

Personality Traits after Recovery from Eating Disorders: Do Anorexia and Bulimia Patients Differ?

When we think about eating disorders, we tend to think about eating disorder subtypes: anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder. A lot of previous work has shown that individuals with AN and BN tend to be anxious, depressed, perfectionistic, and harm-avoidant. Patients with AN also tend to score low on novelty-seeking, impulsivity, and self-directedness, whereas patients with BN score high on novelty-seeking and impulsivity. More recently, however, some researchers began to wonder if there was another way to categorize patients–not according to symptoms, but according to personality traits?

They identified three clusters of personality subtypes that seemed to “cut across” eating disorder diagnoses, outlined below (taken from a previous post):

Three Personality Subtypes in Eating Disorder Patients:

  1. “dysregulated/undercontrolled pattern: characterized by emotional dysregulation and impulsivity”
  2. “constricted/overcontrolled pattern: characterized by emotional inhibition, cognitively sparse representations of self and others, and interpersonal avoidance”
  3. “high-functioning/perfectionist pattern: 
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Excessive Exercise in Eating Disorders

Excessive exercise (EE) is common among eating disorder patients. Indeed, in the study I’ll write about today, 39% of patients engaged in EE. Previous studies have tried to find psychopathological and personality correlates of EE but the results have been inconsistent. Some studies have suggested that impulsivity and addictiveness are highly correlated with EE whereas others found that anxious and depressive traits were more closely associated.

In a retrospective case series study involving outpatients with AN and BN, Penas-Lledo et al. found higher levels of anxiety and depression… among those who were identified as exercising excessively. The authors claimed that exercise might serve to reduce anxiety and stress in individuals with AN. In a similar study with adolescent inpatients with AN, Holtkamp et al. found that anxiety significantly predicted variance in exercise levels. These investigators proposed that anxiety symptoms in combination with food restriction contributed to increased levels

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Think You Are Not “Sick Enough” Because You Didn’t Lose Your Period? Read This.

Anonymous asked, “I’ve never lost my period. Weight restored I am naturally thin, but even at a BMI of 15 or so I always got my period (although it wasn’t always regularly). This makes me feel like I’m not actually sick because I hear about everyone losing their period.”

eatruncats replied: “To the anon who asked about losing periods: For all the times she worries about not being sick enough because she never lost her period, there are people who lost their periods at BMIs of 18, 19, and 20 who worry about not being sick enough because they never got to a BMI of 15. If you have an eating disorder, you are “sick enough.” Period.

As it stands now, amenorrhea–or the loss of three consecutive menstrual cycles–is a diagnostic criterion for anorexia nervosa. Individuals who have not lost their periods are diagnosed with eating disorder … Continue reading →

Predictors of Diagnostic Crossover and Symptom Fluctuation in Eating Disorders

Symptom fluctuation and diagnostic crossover are common in eating disorder patients. A study by Eddy et al. (2008) – who followed patients over an average of 7 years – showed that crossover between subtypes and full-syndrome diagnoses is very common : of those initially diagnosed with anorexia nervosa, almost 73% crossed over to another diagnosis (between symptoms and to bulimia nervosa). More specifically, roughly 50% experienced fluctuation between subtypes (restricting, AN-R, and binge/purge type, AN-BP) and roughly 35% crossed over to bulimia nervosa (a subset experienced both). Of those initially diagnosed with bulimia, roughly 14% crossed over to AN-BP and of those, 3.91% crossed over to AN-R.

This finding (though, well-known to ED specialists and even more well-known to patients) has important implications for treatment. For example, CBT and anti-depressants seem to have positive results in bulimic patients, but not so much in anorexics. What then, about those that crossover … Continue reading →

Benefits of Starving and Why You Don’t Have a “Chemical Imbalance”

Most people hate starving, hate prolonged hunger and suck at dieting. Patients with anorexia nervosa (AN), on the other hand, excel in these areas. How can someone like being hungry? How are they able to exert such “self-control”  (as many non-ED people often say) over their food intake? Part of the answer might lie with serotonin. But don’t worry, there’s no “chemical imbalance” – it is much more complex than that.

In this post, I’m going to continue discussing the review article in Nature Neuroscience (2009) by Kaye et al., focusing on what is currently known or hypothesized about the role of serotonin in anorexia (reminder, findings Kaye et al focuses are specific to restricting-type AN and may not apply to AN-BP or BN).


Serotonin (aka 5-hydroxytryptamine or 5-HT) is a neurotransmitter, meaning that it is a chemical messenger that cells … Continue reading →