Medical Research

On the Efficacy of Self-Induced Vomiting (Purging)

Saren 9 Comments

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

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

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

Tetyana 2 Comments

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 →

Using Animal Research to Justify Eating Disorder Treatment Practices: Are We Going Too Far? (On Eating Junk Food in Treatment – Part II)

Liz 10 Comments

As a follow up to Charlene’s  post on eating hyper-palatable foods during eating disorder treatment , I asked Liz–SEDs’ resident expert on animal behaviour, particularly in relation to binge eating and drug addiction–to look at some of the studies that Julie O’Toole mentioned as evidence for Kartini Clinic’s guidelines of avoiding hyper-palatable foods for the first year of eating disorder recovery. If you missed Dr. O’Toole’s post, please do take a look. Here’s the main conversation that led to this post: 

In the comments, I asked Dr. O’Toole, 

I agree that eating cheetos and sugar-y drinks is ubiquitous but not exactly healthy, and I too question many versions of “normal eating” that people promote (and *everyone* has an opinion), but I wonder — if there’s any evidence for not allowing hyper-palatable foods to patients for a year? And what does the Kartini Clinic consider to be hyper-palatable? Why

… Continue reading →

Serious Restrictive Eating Disorders Occur at Any Weight

Tetyana 8 Comments

Although the words “anorexia nervosa” typically conjure up images of emaciated bodies, eating disorders characterized by dietary restriction or weight loss can — and do — occur at any weight. However, precisely because anorexia nervosa is associated with underweight, doctors are less likely to identify eating disorders among individuals who are in the so-called “normal” or above normal weight range, even if they have all the other symptoms of anorexia nervosa.

Clearly, this is a problem.

For one, there is no evidence that eating disorder not otherwise specified (EDNOS) — a diagnosis given to individuals who do not fulfill all of the criteria for anorexia nervosa or bulimia nervosa — is less severe or less dangerous than full syndrome anorexia nervosa. As I’ve blogged about, individuals with EDNOS have comparable mortality rates (see: EDNOS, Bulimia Nervosa, as Deadly as Anorexia Nervosa in Outpatients) and similar (sometimes even more severe) … Continue reading →

Hypermetabolism in Anorexia Nervosa

Tetyana 21 Comments

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 need to … Continue reading →

Energy Expenditure in Anorexia Nervosa Patients

Tetyana 7 Comments

How many calories do patients with anorexia nervosa need to eat to gain a kilo (2.2 lbs)? It seems like a simple question and one that we should have figured out a long time ago, given the importance (err, necessity) of refeeding and weight restoration in recovery from anorexia nervosa.

Unfortunately, research in this area has often led to contradictory results (see Salisbury et al., 1995 and de Zwaan et al., 2002 for reviews). Fortunately, a paper by Stephan Zipfel and colleagues (2013, freely available here) sheds light on one potential cause of the discrepancies.

But first, some definitions:

TDEE stands for total daily energy expenditure. TDEE has three components: resting energy expenditure (REE), dietary-induced thermogenesis (DIT), and activity-induced thermogenesis (AIT). The gold standard for measuring TDEE is through something called the doubly labelled water technique. REE is usually measured through indirect calorimetry. (These techniques were used in this … Continue reading →

Disordered Eating and Athletic Performance: Where’s the Line?

Emma 4 Comments

If a person severely restricts his diet and exercises for hours each day, he has an eating disorder. If another does exactly the same but it is because she wants to make the lightweight rowing team (which has an upper weight limit), she’s a committed athlete. When the two overlap, and an athlete presents with eating disorder symptoms, how do we distinguish between the demands of the sport and the illness?

I’ve been interested in the distinctions we make between disordered and non-disordered eating and exercise behaviours for a while now. Recently, when I was browsing through articles, I came across a literature review by Werner et al. (2013) (open access) of studies examining weight-control and disordered eating behaviours in young athletes.

The authors start by noting the sheer lack of research that has actually been done in this area. This is worrying: typical onset of eating disorders is during … Continue reading →

Eating Disorders and Irritable Bowel Syndrome

Tetyana 22 Comments

Eating disorder patients commonly complain of gastrointestinal (GI) symptoms including bloating, abdominal pain, and constipation. This is, of course, not surprising. After all, disordered eating behaviours such as self-induced vomiting, laxative abuse, and restriction are bound to have negative effects on the digestive system.

But just how common are GI complaints and functional gastrointestinal disorders (FGIDs) like irritable bowel syndrome among ED patients? And is there more to the relationship than simply ED behaviours causing GI disturbances? Luckily, a growing number of research studies are beginning to shed some light on these questions.

In a study published in 2010, Catherine Boyd and colleagues examined the prevalence of FGIDs among ED patients admitted to a hospital Eating Disorders Unit. They found that out of the respondents (73 in total), 97% had at least one FGID (as evaluated using the Rome II questionnaire). More specifically, on admission, 73% of the … Continue reading →

Models of Anorexia Nervosa: A Few Insights from Our Animal Cousins

Liz 6 Comments

In 1967, Routtenberg and Kuznesof reported a very peculiar phenomenon in rats:

They discovered that when rats were on a restricted feeding schedule (1 hour per day in their experiment) and had free access to a running wheel, their food intake was significantly lower than in control rats, which were on the same feeding schedule but without access to a running wheel. This discrepancy between increased running activity and decreased food intake caused substantial body weight loss, and if rats were not removed from the experimental setup timely, they would eventually die of starvation. This model, later named the activity-based anorexia (ABA) model, is one of the most widely used animal models for the study of anorexia nervosa (AN). (Source)

Of course, rats are not humans. Nonetheless, animal models of anorexia nervosa can inform us of some of the underlying neuropsychological and physiological influences and consequences of … Continue reading →

Nothing to SCOFF at: Screening for Eating Disorders in the Emergency Room

Andrea

As many who have suffered from eating disorders know, these illnesses can often go unnoticed for years. Family members and friends might not be the only ones who don’t catch the signs and symptoms of EDs; doctors, too, may not identify the presence of an eating disorder. Whether or not sufferers desire to get help, the symptoms associated with eating disorders often lead many to present at doctors’ offices and emergency departments, suffering from “mysterious ailments.”

In a study by Dooley-Hash, Lipson, Walton & Cunningham (2012, 2013), 16% of youth 14-20 presenting to the emergency department screened positive for eating disorders. The researchers describe their study in two articles published in the International Journal of Eating Disorders in 2012 and 2013. For this post, I’ll focus on the 2013 article, which highlights the patterns of emergency department use of those who present with eating disorders.

Tetyana has previously written … Continue reading →