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 →
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
… Continue reading →
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:
- “dysregulated/undercontrolled pattern: characterized by emotional dysregulation and impulsivity”
- “constricted/overcontrolled pattern: characterized by emotional inhibition, cognitively sparse representations of self and others, and interpersonal avoidance”
- “high-functioning/perfectionist pattern:
… Continue reading →