Restrained eating has long been considered one of the most potent and consistent risk factors for binge eating and related bulimic pathology in young females. However, negative mood on its own or in interaction with restraint is also shown to predict binge eating and other related eating symptoms (Grilo, 2004; Peterson, Miller, Crow, Thuras, & Mitchell, 2005; Stice & Agras, 1999; Steiger et al., 2005 and Stice et al., 2001; Van Strien, Engels, Van Leeuwe, & Snoek, 2005). Restrained eating refers to the volitional and sustained effort to restrict caloric intake as a weight control technique, either to lose weight or avoid weight gain (Laessle, Tuschl, Kotthaus, & Pirke, 1989). Dietary restraint is hypothesized to increase the risk for onset and maintenance of binge eating and bulimic symptoms (Polivy & Herman, 1985) via metabolic and psychological pathways (Lowe, 2002). This hypothesized restraint-induced loss of control over eating, in turn, may precipitate other compensatory behaviors to control weight such as exercise, fasting and purging. However, despite the vast evidence prospectively supporting this leading model on the link between dietary restraint and binge eating and related disordered symptoms (Leon, Fulkerson, Perry, Keel, & Klump, 1999; Santonastaso, Friederici, & Favaro, 1999), experimental studies do not replicate it (Lowe & Kleifield, 1988; Sysko, Walsh, & Wilson, 2007). Moreover, successful dietary restriction (high restraint in combination with a 10% decrease in BMI) has been shown to decrease binge eating and related psychopathology (Stice, Martinez, Presnell, & Groesz, 2006), suggesting that restraint may not be a necessary precursor of binge eating, as has been shown for a percentage of patients (Bulik, Sullivan, Carter, & Joyce, 1997), that restraint might in fact have a protective quality, and/or that restraint is a multidimensional construct with the potential for negative and positive effects. By extension, the validity of one of the most used measures to test this model, the Restraint scale of the Three Factor Eating Questionnaire (TFEQ-R, Stunkard & Messick, 1985), has been recently put into question (Stice, Cooper, Schoeller, Tappe, & Lowe, 2007; Stice, Fisher, & Lowe, 2004), since it is not negatively correlated with objective measures of short to long-term caloric intake. The latent construct measured by the TFEQ-R remains unknown. One possibility is that it measures intention to restrict rather than actual restrictive eating behavior.
On the other hand, negative mood is emerging as an important factor to explain binge eating in both restrained (Steiger et al., 2005) and unrestrained eaters (Peterson et al., 2005). Furthermore, depression, which is frequently comorbid in eating disorder (ED) patients, has been the only consistent factor across studies associated with worse outcome (Berkman, Lohr, & Bulik, 2007) in bulimia nervosa (BN), an ED characterized by recurrent binge eating followed by maladaptive weight control methods such as purging and fasting (DSM-IV, American Psychiatric Association, 2000). In support of the key role of negative mood in binge eating syndromes, cluster-analytic studies have consistently yielded two reliable diagnostic subtypes, the pure restraint and the mixed restraint-negative mood, where the latter is representative of about one third of ED patients who binge eat (BN and Binge Eating Disorder) and signals a more severe variant of these disorders and a poorer outcome (Chen & Le Grange, 2007; Grilo, 2004; Stice & Agras, 1999; Stice et al., 2001). Because these diet-negative affect subtypes are consistent with etiologic and maintenance models of binge eating, they may capture not only clinical but also at-risk individuals.
Therefore, the present study first examines if a large population of undergraduate females can be also categorized into three different subtypes: the two previously found in clinical samples of eating disordered women, the dietary-restraint and the mixed dietary-restraint-negative mood, and a “healthy” one characterized by low scores on dietary restraint and negative affect. Secondly, it examines the validity of this subtyping scheme by comparing these subtypes on self-reported disinhibition of eating and weekly frequency of binge eating (BE) and weight control behaviors (fasting, purging and exercise). It was hypothesized that women in the restrained group will report significantly more concurrent eating disorder pathology than those in the healthier group, and that the mixed group would report greater severity of eating pathology than the other two groups.
