The purpose of this study was to elucidate the nature of the relationship between dietary restraint and physiological stress, by investigating which eating and body-related constructs are related to salivary cortisol and to perceived stress. Female undergraduates (N=170) completed self-report measures on dietary restraint, appearance beliefs, body satisfaction variables, perceived stress, and eating self-efficacy. Participants also provided two saliva samples. The first sample was collected after awakening, and the second was collected 6–8 h later. A factor analysis was performed in order to reduce redundancy in the set of measures surrounding eating and body attitudes, which yielded three factors. The findings indicated that women with stronger beliefs about the importance of their appearance, as well as negative emotions and cognitions surrounding their body image, had higher levels of cortisol in the afternoon. These appearance and body-related constructs were also associated with higher levels of perceived stress. However, perceived stress was not associated with salivary cortisol. There were no significant relationships between any of the eating or psychological variables and morning cortisol levels. These results suggest that dysfunctional cognitions surrounding appearance and body image significantly contribute to the relationship between dietary restraint and elevations in cortisol excretion. Implications for interventions and women's health are discussed.
Western societies are battling an escalating prevalence of obesity and obesity-related illness (Flegal, Carroll, Kuczmarski, & Johnson, 1998), and food is seen less and less as a source of pleasure, and more of a source of concern (Rozin, Fischler, Imada, Sarubin, & Wrzesniewski, 1999). Americans, and American women in particular, are the least likely to make culinary and pleasure-related associations with food, and are more ambivalent about food than are people from other nations (Rozin et al., 1999). To better understand this ambivalence, researchers have begun to distinguish actual dieting behaviour from mental preoccupation with dieting and food, with the latter referred to as ‘cognitive dietary restraint’(CDR).
CDR is a key construct in the literature on dieting, and refers to the desire to restrict food intake in an effort to maintain one's weight or produce weight loss (Herman & Polivy, 1975). CDR is thought of as an attitude towards food that is, in good part, independent from dieting behaviour. It is largely uncorrelated with caloric intake measured surreptitiously (Stice, Fisher, & Lowe, 2004), and does not necessarily involve a particular set of eating habits. Those scoring high in CDR do not report consuming fewer calories based on food diaries (Beiseigel & Nickols-Richardson, 2004) and they frequently report that they are not currently dieting despite their mental preoccupation with food (Green & Rogers, 1995; Lowe & Timko, 2004). To summarize, the label of CDR or ‘restrained eater’ does not in and of itself imply that one is actively dieting or losing weight, but instead refers to heightened consciousness and preoccupation with food and diet. The purpose of this study was to examine the relationship between CDR (a preoccupation that may serve as a stressor), associated psychological constructs, and an objective physiological stress marker, namely, cortisol.
