It is believed that what differentiates eating disorders is not the concept of food that
differs from disorder to disorder, but rather the attitudes that are characteristics of the
individuals within each disorder. These attitudes are most easily defined through behaviour
based on which people can most commonly be placed into one of four categories. These
categories are people with bulimia nervosa, binge-eating disorder, anorexia nervosa, or ‘normal’
eating behaviour.
Anorexia nervosa is described as a dismissal or rejection of food, to ensure that one’s
body weight will stay below the standard for one’s Body Mass Index, (Marcus, 2006). Bulimia
nervosa is identified by repeated episodes of binge eating in a fairly short period of time, during
which much larger than normal quantaties of food are consumed (Marcus, 2006). Uncontrollable
binge eating coupled with frequent behaviour to avoid weight gain are all features of bulimia,
(Marcus, 2006). Such behaviours include abuse or misuse of laxatives, diuretics and various
other drugs, self-induced vomiting, alongside restrictive dieting or excessive exercise, (Marcus,
2006). A definition of binge-eating disorder could be frequent episodes of binge eating, which
involve rapid eating until one feels uncomfortably full. In addition, one does not necessarily
have to feel physical hunger to binge, (Marcus, 2006). To avoid embarrassment, one would eat
alone and feelings of depression, disgust and guilt would normally follow this, (Marcus, 2006).
Normal eating behaviour is typically characterised by eating three main meals throughout the
day without any unhealthy behaviours such as, binging, purging or restrictive eating, (Marcus,
2006).
It has been shown by Kaltiala-Heino, Rissanen, Rimpelae & Rantanen, (2003) that
women with bulimia nervosa take part in unrestrained behaviours that can often be associated
with highly negative consequences. These negative behaviours are also often considered high
risk. Culbert and Klump (2005) investigated the relationship between eating disorders and
sexual behaviour with impulsivity as an underlying factor. They suggested that sexual
behaviours counteract with the binge eating because they are effectively, more risky, (Culbert &
Klump, 2005). These findings suggest that extreme behaviours are more likely to be influenced
by impulsivity.
Much research has explored impulsivity as a factor within eating disorders and also it’s
effect on normal eating patterns. Impulsivity can be classified as an individual’s tendency to act
or react quickly, irrationally without thinking or without considering the consequences, (Lyke &
Spinella, 2003). Lyke and Spinella, (2003) state that impulsivity may have a considerable effect
on the ability to plan meals in advance and to eat on a regular basis. Subsequently this means an
individual may find it difficult to resist indulging in high fat or unhealthy foods, (Lyke &
Spinella, 2003).
Lacey and Evans (1986) studied a variety of behaviours in conjunction with impulsivity,
one of which was eating disorders. They suggested that there are strong relationships between
binge-eating and forms of impulsivity, (Lacey and Evans, 1986). They also proposed that there
are a variety of impulsive behaviours such as the abuse or misuse of alcohol, drugs, selfmutilation or stolen, (Lacey and Evans, 1986). It was put forward by Lacey and Evans (1986)
that individuals with bulimia nervosa may have a particular behavioral trait within their
personality called multi-impulsive personality disorder. They argue that multiple types of
impulsive behaviours are not part of personality traits but rather are parts of a neurotic illness
similar to depression, (Lacey and Evans, 1986).
Most of the current research has been conducted with bulimic patients or bulimic like
groups, whereas studies with anorexia nervosa are less frequent. Also, within these studies that
look at impulsivity and risk taking with eating disorders it is easier to observe and increase in
impulsivity (within bulimics) than it is to see a decrease (with anorexics).
A study conducted by Butler & Montgomery, (2004) focused on people with anorexia
nervosa and behavioural impulsivity. They showed that many researchers traditionally proposed
that individuals with anorexia nervosa and bulimia nervosa may have two opposing behaviours,
(Butler & Montgomery, 2004). They found when measuring impulsiveness, venturesomeness,
and empathy, that the relationship between anorexia and impulsivity was complex, (Butler &
Montgomery, 2004). More specifically, individuals with anorexia were more likely to show
restraint on a self-reported questionnaire, their behaviour was more impulsive and therefore their
self-awareness was lower, (Butler & Montgomery, 2004).
The most recent review, conducted by Howard et al., (2020) looked at impulsivity and
compulsivity amongst anorexic and bulimic adult female groups. Their review supported a
trans-diagnostic approach to eating disorders (Howard, et al., 2020). They found that results
were variable and came across mixed findings between the two eating disordered groups. This
review shows that further research is needed to identify if there is a relationship between
impulsivity and eating disordered groups.
There is much researchexploring the association between eating disorders and various
behaviours. However, the exisisting reviews keep their main focus, when looking at impulsivity,
to bulimia nervosa. This review hopes to expand on previous research and focus to eating
disorders on the whole and look at an adolecent sample. There have already been reviews
conducted on adult females (18+) but there is a gap in the research to observe and systematically
review these behaviours from an earlier age.
Research Question and Aims
The overall aim of this systematic review is to look at the role of impulsivity and risk
taking behaviour in eating disorders. More specifically, the current research will be examined to
identify whether or not different eating disorederd groups are more likely to exhibit impulsive
behaviour or take more risks.
For the prurpose of this systematic review, the population, exposure and outcome (PEO)
framework to inform the review objectives.
The population studied will be: adolescent females with an eating disorder. Much
research on this topic has been conducted with adult women and impulsivity, therefore this
review will specifically focus on adolecent females to explore if the relationship between eating
disordered groups and impulsivity/risk taking behaviour can be observed from an early age.
The Exposure will be: impulsivity and/or risk taking behaviour.
The Outcome observed will be: to identify if impulsivity or risk taking behaviour traits
are more prevelant in adolesent females with eating disorders.
Research Question: Are eating disordered groups affected by impulisivity or risk taking
behaviour?
Methods
Systematic reviews are largely used in medical research and are seen to be a key
component to which evidence-based healthcare stems from (Munn et al. 2018). It is a complex
form of analysis and research that medical researchers carry out to synthesize all the available
evidence on a specific question. A systematic review is a type of literature review that uses
controlled methods to collect data from secondary sources, critically evaluate these studies, and
collate the findings (Munn et al. 2018). In order to conduct a systematic review, a research
question must be formulated to identify and synthesize studies that relate to the review question.
Systematic reviews are designed to give a comprehensive summary of the current research.
Databases used for article searches:
PubMED https://pubmed.ncbi.nlm.nih.gov/?otool=iukqmulib
PsychINFO https://go.apa.org/psycinfo/
Web of Science http://methods.sagepub.com.ezproxy.library.qmul.ac.uk/video
Cochrane Library, https://www.cochranelibrary.com/
Google Scholar https://scholar.google.co.uk/
Prospero https://www.crd.york.ac.uk/prospero/
Search Terms: eating disorder groups, eating disorder like groups, impulsivity, risk
taking behaviour, anorexia and impulsivity, bulimia and impulsivity, overeating and impulsivity,
female adolecents.
Inclusion Criteria: Studies included in this review include anorexia and/or bulimia,
along with impulsivity/risk taking behaviour and including adolescents. Only studies conducted
in english will be included. Studies with participants meeting an eating disorder diagnosis using
the DSM or ICD criteria will also be included.
Exclusion Criteria: Studies including only one of the variables will be excluded.
Studies using adult males participants, over the age of 21 will be excluded. Articles that do not
report statistical comparisons between the groups will be excluded.
Data Extraction
Data will be collected by initially screening article titles and abstracts to establish their
relevance. The appropriate studies meeting the criteria will be compiled in full text for further
screening. Eating disorder diagnosis, impulsivity assessment, sample characteristics and the
statistical results will all be looked at from each study that fits the inclusion criteria.
Assessment of quality:
All the studies included in this review will be evaluated for quality of methods used and
potential for bias using an appropriate scientific criterion. This will allow checks for various key
points relating to quality, such as the reliability and validity of the measures used, the
interpretations and the limitations. A descriptive assessment of the risk of bias will be added,
along with any implications these may bring.
Data Synthesis
A narrative synthesis of the studies included in this review will be compiled. This
approach consists of synthesising and summarising the findings from various relevant studies.
This form of synthesis has been chosen to be able to include more data that may be excluded if
another form of synthesis is used i.e. Meta-analysis.
