Simone Claire Mölbert

Assessing body image in anorexia nervosa using biometric self-avatars in virtual reality: Attitudinal components rather than visual body size estimation are distorted

Background Body image disturbance (BID) is a core symptom of anorexia nervosa (AN), but as yet distinctive features of BID are unknown. The present study aimed at disentangling perceptual and attitudinal components of BID in AN. Methods We investigated n = 24 women with AN and n = 24 controls. Based on a three-dimensional (3D) body scan, we created realistic virtual 3D bodies (avatars) for each participant that were varied through a range of ±20% of the participants’ weights. Avatars were presented in a virtual reality mirror scenario. Using different psychophysical tasks, participants identified and adjusted their actual and their desired body weight. To test for general perceptual biases in estimating body weight, a second experiment investigated perception of weight and shape matched avatars with another identity. Results Women with AN and controls underestimated their weight, with a trend that women with AN underestimated more. The average desired body of controls had normal weight while the average desired weight of women with AN corresponded to extreme AN (DSM-5). Correlation analyses revealed that desired body weight, but not accuracy of weight estimation, was associated with eating disorder symptoms. In the second experiment, both groups estimated accurately while the most attractive body was similar to Experiment 1. Conclusions Our results contradict the widespread assumption that patients with AN overestimate their body weight due to visual distortions. Rather, they illustrate that BID might be driven by distorted attitudes with regard to the desired body. Clinical interventions should aim at helping patients with AN to change their desired weight.

Depictive and metric body size estimation in anorexia nervosa and bulimia nervosa: A systematic review and meta-analysis

A distorted representation of ones own body is a diagnostic criterion and core psychopathology of both anorexia nervosa (AN) and bulimia nervosa (BN). Despite recent technical advances in research, it is still unknown whether this body image disturbance is characterized by body dissatisfaction and a low ideal weight and/or includes a distorted perception or processing of body size. In this article, we provide an update and meta-analysis of 42 articles summarizing measures and results for body size estimation (BSE) from 926 individuals with AN, 536 individuals with BN and 1920 controls. We replicate findings that individuals with AN and BN overestimate their body size as compared to controls (ES=0.63). Our meta-regression shows that metric methods (BSE by direct or indirect spatial measures) yield larger effect sizes than depictive methods (BSE by evaluating distorted pictures), and that effect sizes are larger for patients with BN than for patients with AN. To interpret these results, we suggest a revised theoretical framework for BSE that accounts for differences between depictive and metric BSE methods regarding the underlying body representations (conceptual vs. perceptual, implicit vs. explicit). We also discuss clinical implications and argue for the importance of multimethod approaches to investigate body image disturbance.

Body size estimation of self and others in females varying in BMI

Previous literature suggests that a disturbed ability to accurately identify own body size may contribute to overweight. Here, we investigated the influence of personal body size, indexed by body mass index (BMI), on body size estimation in a non-clinical population of females varying in BMI. We attempted to disentangle general biases in body size estimates and attitudinal influences by manipulating whether participants believed the body stimuli (personalized avatars with realistic weight variations) represented their own body or that of another person. Our results show that the accuracy of own body size estimation is predicted by personal BMI, such that participants with lower BMI underestimated their body size and participants with higher BMI overestimated their body size. Further, participants with higher BMI were less likely to notice the same percentage of weight gain than participants with lower BMI. Importantly, these results were only apparent when participants were judging a virtual body that was their own identity (Experiment 1), but not when they estimated the size of a body with another identity and the same underlying body shape (Experiment 2a). The different influences of BMI on accuracy of body size estimation and sensitivity to weight change for self and other identity suggests that effects of BMI on visual body size estimation are self-specific and not generalizable to other bodies.

Validierung der deutschsprachigen Version der Physical Appearance Comparison Scale (PACS): Psychometrische Eigenschaften und Zusammenhang mit Essverhalten, Körperbild und Selbstwert

The Physical Appearance Comparison Scale (PACS [14]) is the most commonly used validated measure of body-related social comparison habits. Here we investigate reliability and construct validity of the PACS in a German sample. Participants (n=75 men, n=75 women and n=25 women with a confirmed diagnosis of anorexia nervosa) completed the PACS along with measures of eating disorder pathology, body image and self-esteem. Results show an adequate internal consistency of the PACS for the female subgroups and medium to high correlations with eating disorder pathology, body image and self-esteem. PACS total score differed significantly between groups, with men scoring lowest and women with anorexia nervosa scoring highest. We conclude that the PACS is a sufficiently reliable and valid measure of body-related social comparison habits in women. In men, it should only be used with special care. The PACS is generally suitable to promote patient studies testing the role of social comparisons for the patho-mechanisms of eating disorders.

Multimodal Body Representation of Obese Children and Adolescents before and after Weight-Loss Treatment in Comparison to Normal-Weight Children.

Objective The aim of the study was to investigate whether obese children and adolescents have a disturbed body representation as compared to normal-weight participants matched for age and gender and whether their body representation changes in the course of an inpatient weight-reduction program. Methods Sixty obese (OBE) and 27 normal-weight (NW) children and adolescents (age: 9–17) were assessed for body representation using a multi-method approach. Therefore, we assessed body size estimation, tactile size estimation, heartbeat detection accuracy, and attitudes towards one’s own body. OBE were examined upon admission and before discharge of an inpatient weight-reduction program. NW served as cross-sectional control group. Results Body size estimation and heartbeat detection accuracy were similar in OBE and NW. OBE overestimated sizes in tactile size estimation and were more dissatisfied with their body as compared to NW. In OBE but not in NW, several measures of body size estimation correlated with negative body evaluation. After weight-loss treatment, OBE had improved in heartbeat detection accuracy and were less dissatisfied with their body. None of the assessed variables predicted weight-loss success. Conclusions Although OBE children and adolescents generally perceived their body size and internal status of the body accurately, weight reduction improved their heartbeat detection accuracy and body dissatisfaction.

Effectiveness of body image directed interventions in patients with anorexia nervosa: A systematic review

OBJECTIVE Body image (BI) disturbances are one of the core symptoms of anorexia nervosa (AN). They have been shown to be associated with depression and anxiety at all treatment stages and are a reliable predictor of relapse. Considering the importance for the course of AN, direct targeting of BI disturbances is still underemphasized in the treatment of patients with AN. METHOD In this systematic review, conducted according to the PRISMA statement, the evidence on BI directed interventions in AN is synthesized. RESULTS N = 11 studies investigating mirror exposure, video confrontation, virtual reality body exposure and treatment programs were analyzed. No systematic risk of bias within or across studies could be identified. The included studies show that BI directed interventions may be efficacious in improving BI related outcomes. However, the evidence regarding an additional effect of BI interventions added to established treatments for patients with AN, is unclear. DISCUSSION The evidence base on BI interventions for patients with AN is scarce. It is not possible to identify types of BI intervention that can be seen as the most promising. Advantages of new technologies such as virtual reality or a combination of BI interventions with techniques for stress reduction are discussed.