Physiology

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 →

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 →