El concreto

It is acknowledged that the systematic classification of eating disorders is essential for both researchers and clinicians alike, as it permits consistency in diagnosis and assessment, can assist in evaluation and comparison across the field, and can facilitate treatment decisions and subsequent outcome for the patients (NICE, 2004; Thomas et al., 2009). However, differences still exist between the two major classifications systems (DSM-5 & ICD-10; APA, 2013; WHO; 2010). Considerable revisions have been made to the DSM-5, however the classification of eating disorders is still a topic of considerable controversy and debate amongst academic researchers and clinicians alike (e.g., Fairweather-Schmidt & Wade, 2014; Jordan et al., 2014; Quick, Berg, Bucchianeri, Byrd-Bredbenner, 2014).

A crucial theoretical position that has dominated the field in the last decade is that of the transdiagnostic model of eating disorders (Fairburn, Cooper & Shafran, 2003). This theory proposes that there are common risk factors and mechanisms that underlie eating psychopathology, and proposes that individual differences occur in the manifestations of symptoms (such as restrictive or binge/purge features) as opposed to the underlying causes and maintenance factors (Fairburn et al., 2003). The transdiagnostic model identifies four key features that exist across the diagnostic categories, which Fairburn and colleagues propose underpin eating psychopathology. Factors of perfectionism, low self-esteem, mood-intolerance and interpersonal difficulties interact with the core eating psychopathology of an over valuation of eating, shape and weight, and thus contribute towards the development and maintenance of eating psychopathology (Fairburn et al., 2003). Considerable evidence supports the role of each of the four main factors within the model, in addition to evidence from clinical populations supporting the validity of a transdiagnostic model, as opposed to distinct diagnostic categories (Fairburn et al., 2007). For example, Milos and colleagues (2005) demonstrated that just one third of individuals with eating disorders retained their original diagnosis over the course of a 30 month period.

Core eating psychopathology.

Fairburn and colleagues (2003) proposed that the over-valuation of eating, shape and weight is of primary importance in maintaining eating psychopathology, and that many of the clinical features of eating disorders stem from this core psychopathology. Central to the eating disorders is a dysfunctional system for evaluating self-worth, which is based primarily around eating habits, shape and weight, and individual control over these factors (Fairburn et al., 2003). As a consequence, eating disordered individuals become preoccupied with their weight, eating and appearance, and behavioural and attitudinal features of the eating disorders can emerge, such as extreme dietary restraint, binging and purging behaviour to aid weight loss (Fairburn et al., 2003).

Clinical perfectionism.

Fairburn and colleagues (2003) suggested an interaction between perfectionism and the core eating psychopathology. Indeed, increased levels of perfectionism has been found to not only precede the development of an eating disorder (Bardone-Cone et al., 2007), but is also associated with increased levels of severity (Sutander-Pinnock, Woodside, Carter, Olmsted, & Kaplan, 2003) and poorer treatment outcomes and recovery (Forbush, Heatherton & Keel, 2007).

Self-esteem.

Low self-esteem is characterised by a pervasive negative view of oneself, which can obstruct eating behaviour change, and ultimately recovery (Fairburn et al., 2003). Low levels of self-esteem are commonplace among those with elevated eating psychopathology (Gilbert & Meyer, 2005), and across mental health issues more widely, such as depression (Courtney, Gamboz & Johnson, 2008).

Mood intolerance.

Mood intolerance within the transdiagnostic model refers to a difficulty in coping with adverse mood states, such as anger, depression or anxiety, which can trigger inappropriate methods of mood regulatory behaviour, such as binge eating, intense exercise behaviour and self-induced vomiting (Fairburn et al., 2003). Other forms of dysfunctional mood regulatory strategies include self-harm and substance abuse, which have been found to commonly occur among eating disorder patients (e.g. Claes, Vandereycken &Vertommen, 2001; Paul, Schroeter, Dahme & Nutzinger, 2002), and highlighting the challenges with emotion regulation in this group. Indeed, higher levels of difficulties with emotion regulation have been reported among clinical populations in comparison to healthy controls (e.g. Brockmeyer et al., 2014; Harrison, Sullivan, Tchanturia and Treasure, 2010).

Interpersonal difficulties.

The last factor outlined within the transdiagnostic model is that of interpersonal difficulties. Fairburn and colleagues (2003) noted several interpersonal components of eating disorders that led to the inclusion of this factor within the transdiagnostic model. For example: triggers of binge eating tended to be interpersonal in nature; clear links exist between interpersonal difficulties and self-esteem; interpersonal environments can heighten eating, shape and weight concerns; and poor interpersonal functioning can impact negatively on the efficacy of treatment (Agras et al., 2000).

The transdiagnostic model of eating disorders and the athletic population

Whilst classification criteria are still important within research and clinical environments, the transdiagnostic model offers a novel approach to eating psychopathology, by considering the

psychosocial factors that exist across the diagnostic categories (Fairburn et al., 2003). The approach offers clear avenues for prevention and intervention, regardless of patient background and diagnostic status. Importantly, there is evidence to suggest that the transdiagnostic model is relevant for eating psychopathology in the athletic population (Shanmugam, Jowett & Meyer, 2011), further reinforcing the value of the model beyond the clinical population, within which it was developed. Indeed, three of the core factors of the model were supported as contributing to increased levels of eating psychopathology in athletes (Shamnugam et al., 2011). In particular, interpersonal difficulties, low levels of self-esteem, high levels of self-critical perfectionism and depressive symptoms were predictive of eating psychopathology in athletes, regardless of sport type and level of competition (Shanmugam et al., 2011). Mood intolerance and specifically, dysfunctional mood regulatory strategies were not examined in this model, hence remains an area yet to be verified within the athletic population.