Paola Tubaro ANAMIA INSNA Sunbelt2014 St. Pete's Beach FL 22.02.2014
Body image and eating
The effects of personal
University of Greenwich, London &
University of Greenwich, London!
Antonio A. Casilli!
Telecom ParisTech & EHESS, Paris!
Thomas W. Valente!
University of Southern California, Los
Eating disorders and body image
• Eating disorders are characterized by abnormal eating behaviors
with either insuﬃcient or excessive food intake and exercising to
the detriment of physical and mental health.
• Eating disorders are accompanied by distorted perceived body
Body image and behavior
Self-perceived image aﬀects individuals’ behavior
Source: A Brazilian campaign against anorexia
Body image and peer effects
Networks, peer eﬀects and body image
• Peer pressure is know to be a signiﬁcant contributor to body image
concerns and eating attitudes (Costa-Font and Jofre-Bonetpeer, 2011).
• "Teen girls' concerns about their own weight, about how they appear to
others and their perceptions that their peers want them to be thin are
signiﬁcantly related to weight-control behavior“ (Mackey and La Greca,
• We use a network perspective to look more closely at the social
environment to establish the extent to which interpersonal relationships
aﬀect the perception of individuals with respect to their body image
A personal networks approach
• We use ego-centric network data collected through a web survey
of 284 English- and French-speaking respondents with eating
disorders (Research project: Anamia).
• Network data include information on their broadly deﬁned
personal networks including face-to face and Internet-based
The online questionnaire
General personal networks: using a visual sociogram
• In the online questionnaire, a
graphical ego network applet
enabled participants to draw
their personal networks!
• Two graphical networks each!
– general personal network
(school, family, workplace
– online personal network
(forums, blogs etc.)!
The ANAMIA study
Network structure and composition
• Each graphical interface
enabled participants to:!
– Add alters, specifying name,
gender, and qualiﬁcation
(friend, family member etc.)!
– Position emotionally closest
alters next to ego, and less
close alters further away!
– Draw ties between alters;!
– Group alters in social circles
(schoolmates, member of a
sports team, participants in a
The ANAMIA study
Personal networks as drawn by respondents
Some examples of personal networks
Personal network data
• We reconstructed 265 ego-networks
• Two types of network variables:
1. Structural :
– Adjusted density – taking into account social circles
– Size – the number of all alters
Online and offline alters (multiplexity) (Blau index)
Level of intimacy (proportion)
Gender (proportion and variance)
Qualification (Blau index)
Social, demographic and economic
age, gender, geographic location,
employment, qualiﬁcations, income, family
structure, profession of parents, etc.;!
Body and health !
Body image (how they see themselves, how
others see them, how they would like to look);!
Body characteristics (current weight;
minimum and maximum weight achieved;
desired weight; weight believed to be healthy
for them; height; BMI); !
Exercise and sports practice; !
Health (what eating disorder, if any; whether
currently or previously under treatment and if
yes, for what diagnosis, with which
professionals, and since when; the
importance of health for them, for their
families, and for their friends);!
Some basic descriptive statistics:!
• 36 FR; 148 UK!
• ender: 95% women;!
• ge: Average 21.7 (both FR and UK);!
• tudents: Average FR 66%, UK 69%;!
• orkers: Average FR 34%, UK 41%;!
• MI is normal for 53.96% of participants;
underweight for 27.55, overweight for 18.49%;!
• ating disorders: EDNOS (FR 47%, UK 45%);
Anorexia nervosa (FR 17%, UK 34%); bulimia
nervosa (FR 28%, UK 16%); Binge eating (FR
8%, UK 5%);!
• reatment: over 50% of the participants who
reported an eating disorder are being treated
Self-perception & Body image
Figure Rating Scale
1. If I had to describe myself, I would say that I look like (perceived body image - D)
2. If I could choose, I would like to look as (ideal body image - C)
3. People usually say that I look like (mediated body image - O)
Each of these variables is measured on a scale ranging from 1 – very thin silhouette – to
9 – corpulent silhouette.
D – C: Diﬀerence between self-description and how one would choose to look;
D – O: Diﬀerence between self-description and how people think others see them.
A positive diﬀerence would indicate that the respondent’s current body image is
heavier than his/her ideal or mediated body image. A negative diﬀerence would
indicate the opposite.
• Two-stages econometric analysis. As a first step, discrepancies in the two
forms of body image are modeled for the whole sample. Secondly, we
evaluate the determinants of discrepancies in body image for individuals in
different BMI categories.
• Model: bivariate ordered probit model to account for the joint distribution of
the two forms of body image distortions, as a function of both individual
attributes and personal network characteristics.
• For the analysis we used the bioprobit Stata program written by Sajaia (2008).
• As our sub-samples consist of a limited number of observations, we check for
the robustness of our models by applying a simple stochastic re-sampling
procedure based on bootstrapping techniques.
• djusted density has an effect on D-C.
This result is also confirmed for the
normal weight and overweight subsamples.
• ize is significant only for over- and
• elational proximity matters for D-C,
for overweight only.
• eterogeneity in sex also matters for
over- and under-weight individuals.
• roportion of females: negative effect
for the underweight, positive effect for
• ositive effect of BMI (difference
between individual BMI and country-level
average BMI): The more corpulent I am
relative to my general social
environment, the more dissatisfied I am
with my body image.
• ositive effect of medical treatment on
both D – C and D – O.
• egative effect of age: older people
seem to have narrower gaps.
• ositive effect of doing sports on both D
– C and D – O.
Eﬀects of network structure and composition
• ﬀects of individual variables conﬁrm ﬁndings from the literature (peer eﬀects
from social environment broadly interpreted)
• n addition, we ﬁnd evidence of network eﬀects on body image distortions
For more information: www.anamia.fr/en
Contact: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org