Whose Culture is it Anyway? Disentangling Culture and Eating Disorders – Part 2

In this post I’ll continue on the trend of considering the “culture bound” nature of eating disorders by looking at another commonly-cited article about eating disorders and culture. In this article, Keel and Klump (2003) look at the cultural and historical facets of anorexia and bulimia. They looked at whether eating disorders were present in other sociohistorical and cultural contexts in order to determine whether AN and BN are “culture bound.”

Their research, as I alluded to at the end of the first post in this series, suggests that anorexia is not culture bound (i.e., it can occur in the absence of certain aspects of culture), while bulimia is (i.e., it only/primarily appears in certain cultural contexts). As this finding might actually run counter to what popular press would have us believe, looking at this article provides us some interesting insight into how spin can really be everything. … Continue reading →

Demystifying the Genetic and Environmental Influences on Disordered Eating

Genetics play an important role in the development of eating disorders and disordered eating behaviours. To date, many (over 30!) twin studies have been done and all but two found significant genetic effects on the development of eating disorders and disordered eating. However, no methodology is without limitations and tentative conclusions become more convincing when the findings are confirmed using different experimental approaches.

Twin studies, while they offer many advantages, are not that good when it comes to detecting shared environmental effects on a particular trait (literally, evens that happen to both twins and affect them in the same way). Fortunately, twin studies are just one of several different ways that researchers can use to study heritability(A quick reminderHeritability measures the amount of the variability in an observable trait/behaviour that can be attributed to genetic variation. This is NOT the same as … Continue reading →

The Genetics of Thin-Ideal Internalization

The Tripartite Model of body image dissatisfaction postulates that three factors (peers, parents, and media) affect body image dissatisfaction and disordered eating through thin-ideal internalization and appearance comparison.

Thin-ideal internalization is the extent to which one accepts or “buys into” socioculturally defined beauty standards of thinness. The idea is that the more someone internalizes these standards, the more likely they are to engage in behaviours to achieve their “ideal”, and the more likely they are to develop an eating disorder.

A growing number of of studies have been done evaluating the validity of this model. Although I’m not well-read on the subject, it does seem like there is a growing number of studies showing an association between thin-ideal internalization and disordered eating practices.

But is the picture complete? Are peers, parents, and media the only or even the main factors that influence the extent of … Continue reading →

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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Can Puberty Affect the Development of Eating Disorders?

Eating disorders typically begin in adolescence. One common explanation for this is that during adolescence females are increasingly exposed to the media, thin models, and dieting. While this is probably true to some extent, it doesn’t explain why the rates of eating disorders are quite low despite the high levels of exposure to thin models in the media. Out of 100 girls, only a handful develop eating disorders, yet all of them are exposed to the same magazines and TV shows.

This means there must be some other factors that differ between this group of girls. One hypothesis is that hormonal changes during puberty may modulate the genetic risk factors for eating disorders. These changes may “turn on” genes that predispose individuals to eating disorders. Previous research has shown that genetic factors modulate disordered eating (eating disorders have a high heritability), but how? What are the mechanisms of this … Continue reading →

Anorexia Nervosa: Can We Blame The Season Of Birth?

You might have heard that individuals born between the months of June – August (or sometimes March – August) have a higher chance of developing anorexia nervosa. But is it true? A lot of studies have been done to investigate the question of whether a season of birth (or a month) correlates with a higher risk of anorexia or bulimia nervosa. The results are inconsistent, weak, and fraught with methodological problems.

But first, how could seasons (or the average temperature during birth, or conception) have an effect on the etiology of eating disorders? What’s the hypothesis?

There seem to be two main ideas (summarized in Winje et al., 2012):

  1. alterations in neuropsychological function as a result of sunlight exposure during gestation or postpartum, maternal infections during pregnancy, or nutritional changes (seasonal variation in nutrients, vitamins)
  2. alterations in fertility/reproductive patterns of the parents due to cultural influences, disordered eating in
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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 →