Anorexic patients think they are larger than they actually are, but researchers found that they correctly assessed the dimensions of others.
In an observational study of patients with anorexia nervosa, patients' perception of their own shoulder width was significantly associated with a patients' eating concerns (P<0.0009), body concerns (P<0.0001), and body weight at onset of anorexia (P=0.049), according to Dewi Guardia, MD, of the Université Lille Nord de France, and colleagues.
What's more, their judgments of their own girth were significantly different from their estimates of someone else's size (P=0.02), Guardia and co-authors wrote online in PLOS One. Members of a control group, on the other hand, did not have significant differences in assessments of self and others (P=0.447).
The researchers set out to determine whether anorexic patients' erroneous size assessment was associated with their view of the self or if their perception of size was generally impaired.
"Patients with anorexia nervosa usually report feeling larger than they really are," the authors wrote, adding, "This body overestimation appears to be related not only to the patient's body image, but also to an abnormal representation of the body in action."
The study included 25 women with anorexia nervosa who were patients at an eating disorder clinic and 25 women matched for age, education, and height, and who had a normal body mass index (BMI).
Each group was surveyed on body shape and eating concerns, as well as the participants' "drive for thinness" and "body dissatisfaction."
Each participant was then presented with projected doorways or hallways of varying size. They were asked to imagine themselves walking through the projection and to determine if they could do so without having to turn sideways. They were then asked to do the same visualization, but with the researcher walking through the opening.
There was a significant difference between how anorexic patients perceived themselves versus the researcher (P=0.02), while there was not a significant difference among members of the control group (P=0.447).
Patients' first-person perspective of their body weight was significantly correlated with weight prior to disease onset (ρ=0.379, P=0.049), but not weight over the preceding month (P=0.422) or preceding 6 months (P=0.151).
The researchers found significant positive correlations between anorexic patients' perceived size and body concern scores (ρ=0.548, P<0.0001), eating concerns total scores (ρ=0.457, P=0.0009), "drive for thinness" scores (ρ=0.487, P=0.0003), and body dissatisfaction scores (ρ=0.547, P<0.0001).
The authors concluded that "a population of anorexia nervosa patients significantly overestimated their own passability (relative to a control group) in a simulated body-scaled action."
They further explained their results by adding that "[t]he performance differences between the anorexia nervosa and control groups were not likely due to worse discrimination of visual stimuli" but that the "results suggest that the overestimation of the passability ratios in anorexia nervosa are likely to be caused by an overestimation of their own body schema."
Primary source: PLOS One