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 … Continue reading →
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 →
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 →