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alone is not sufficient for recovery. The Sociometer theory will therefore predominantly be used for the design and interpretation of research in this Thesis. The next section will outline the role of self-esteem in eating behaviour and the overvaluation of shape and weight in the evaluation of self-worth.

2. Self-esteem in eating behaviour and eating

disorders

Two of the most extensively researched eating disorders are Anorexia Nervosa (AN) and Bulimia Nervosa (BN). AN is characterised by excessive dieting which leads to a low weight, a pathological fear of weight gain and an excessive influence of shape or weight on self-

evaluation. BN is characterised by frequent episodes of binge-eating (uncontrollably consuming large amounts of food), followed by compensatory behaviours such as vomiting or fasting in order to avoid weight gain. People who exhibit clinically significant pathology but do not satisfy inclusion criteria for AN or BN have been commonly diagnosed with Eating Disorder Not

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Otherwise Specified (EDNOS). The revisions made for the DSM-5 (American Psychiatric Association, 2013) have also introduced Binge Eating Disorder (BED), which was previously diagnosed under the EDNOS label, and is characterised by uncontrollable over-eating. In the UK, the annual incidence of EDs (between the ages of 10 and 49) is approximately 37 per 100,000 people (Micali, Hagberg, & Treasure, 2013)..

Although low self-esteem is common in both disorders, it is thought to play a different role in AN compared to BN. Fairburn, Shafran and Cooper (1998), in their cognitive behavioural model of AN, argue that people with AN use self-starvation as an expression of self-control, from which they derive feelings of accomplishment. In a stepwise regression model of traits predictive of AN symptom severity, self-control accounted for 19% of the variance (Birgegard, Björck, Norring, Sohlberg, & Clinton, 2009). Marilyn Lawrence wrote: “Anorexics are attempting to solve the problem of their own powerlessness [...] The struggle takes the form of an effort to transcend the body which debases them, and to achieve self-respect through self-denial.” (Lawrence, 1979, p.93) The paradox is that people with AN are able to maintain very rigid control over their eating, and yet perceive their own self-control as poor (Horesh, Zalsman, & Apter, 2000). Perfectionism is also thought to contribute to the pathology: people with AN tend to score significantly higher on measures of perfectionism than healthy controls, with the score positively correlated with symptom severity (Halmi et al., 2000) and negatively with treatment outcome (Sutandar-Pinnock, Woodside, Carter, Olmsted, & Kaplan, 2003). Excessively high standards can exacerbate the anorexic behaviour and have a negative effect on self-esteem. However, it must be noted that low self-esteem in AN may be partially attributable to

depression, which is highly comorbid: in one longitudinal study, 68% of women diagnosed with AN had also been diagnosed with a major depressive disorder (Halmi et al., 1991). Once depression is controlled for, differences in self-esteem between people with AN and restrained eaters (people who voluntarily restrict their diet) are significantly reduced (although they still remain lower than healthy controls) (Wilksch & Wade, 2004).

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In BN, low self-esteem is theorised to contribute to the binge-purge cycle. Low self- esteem (Laessle, Tuschl, Waadt, & Pirke, 1989) and elevated perfectionism (Vohs, Bardone, Joiner, & Abramson, 1999) are both typical of BN. Bardone, Vohs, Abramson, Heatherton, & Joiner (2000) found that BN was best predicted by a combination of high perfectionism, body dissatisfaction, and low self-esteem. Vohs et al. (1999) theorise that the binge-purge cycle can arise as a consequence of holding oneself to very high standards (e.g., low target weight), but lacking the confidence that they can be achieved. Repeated self-control failures (binges) serve to negatively affect self-esteem and therefore exacerbate the symptoms. This explanation was adapted from the diathesis-stress model of depression, which proposes that perfectionism and life stress interact to predict depressive pathology (Hewitt & Dyck, 1986). Impulsivity also plays a role in bulimic behaviour, as people with BN tend to be more impulsive than those with AN or healthy controls (Díaz-Marsá, Carrasco, & Sáiz, 2000), which can leave them more susceptible to engage in the binge-purge cycle.

Restrained eaters (REs), defined as people who deliberately attempt to restrict their diet (either in the types or quantity of food) with the intention of weight loss, often exhibit similar behavioural and cognitive patterns as those with eating disorders. Similar to BN, restrained eaters are often unable to consistently sustain the restraint, which leads to overeating – often triggered by the experience of negative emotions (Cools, Schotte, & McNally, 1992; Polivy & Herman, 1999). REs also report lower self-esteem than unrestrained eaters (unREs) (Wilksch & Wade, 2004). REs with low self-esteem are more prone to abstinence violation, or the ‘what the hell’ effect (Herman & Mack, 1975), where a single lapse in restraint leads to overeating (Polivy, Heatherton, & Herman, 1988) – which is behaviourally similar to the way binges are thought to be triggered in BN. Low self-esteem is also associated with other precursors of clinically disordered eating behaviour, such as body dissatisfaction (Tiggemann, 2005). It must be noted that low self-esteem does not, by itself, predict restrained eating; rather, body dissatisfaction predicts both restraint and low self-esteem (Johnson & Wardle, 2005).

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2.1. SHAPE- AND WEIGHT-BASED SELF-ESTEEM

While low self-esteem is common in both EDs and in dietary restraint, they are not exclusively associated. However, what does appear to be specifically important in ED pathology is Shape- and Weight-Based Self-esteem (SAWBS) (Geller et al., 1998). SAWBS refers to the over-valuation of one’s shape and weight in assessing one’s self-worth and is typically assessed using the SAWBS Inventory (Geller, Johnston, & Madsen, 1997; Geller et al., 1998). Participants are asked to select personal attributes which have affected how they felt about themselves over the past four weeks. They are then asked to order-rank these attributes in order of importance and assign them a relative importance value. The relative importance of shape and weight is designated the SAWBS score. The inventory reliably discriminates between people with EDs, those with other psychiatric disorders, and healthy controls – both adults and children/adolescents with an ED consistently score higher (Geller et al., 1998; Serpell, Neiderman, Roberts, & Lask, 2007). Clinical research in AN populations indicates that a decrease in weight is correlated with an increase in self-esteem (Brockmeyer et al., 2012). Conversely, SAWBS significantly decreases as a consequence of treatment (Geller, Zaitsoff, & Srikameswaran, 2005). One study has found that this decrease can be qualified by a shift in self- esteem source: outpatients enrolled in a treatment programme decreased their reliance on shape and weight as a source of self-esteem, but increased their reliance on personal relationships (Geller, Cassin, Brown, & Srikameswaran, 2009)

In non-clinical samples, girls who evaluate their self-worth primarily on the basis of their body shape and weight have also been found to score higher on measures of anorexic and bulimic cognitions than girls who do not (Geller, Srikameswaran, Cockell, & Zaitsoff, 2000). Higher SAWBS scores have also been found to mediate the correlation between self-esteem and dietary restraint (Wade & Lowes, 2002): that is, low self-esteem is positively associated with ED pathology, but only if feelings of low self-worth are associated with an over-valuation of shape and weight. Although no studies have directly addressed this, it can be hypothesised that an over-emphasis on shape and weight in the evaluation of self-worth typically precipitates

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restrained eating behaviour and ED pathology. This hypothesis is consistent with both the DSM criteria for both AN and BN and with Bardone et al.’s (2000) prospective research which found that low self-esteem is one of the factors in the cognitive profile predictive of future bulimic symptomatology.