Eating behaviors and negative affect in college women's everyday lives.

A growing body of research seeks to understand the relationship between eating behaviors and mood, with the goal of identifying factors that may influence people to engage in unhealthy or disordered eating behaviors (1,2). One limitation of most previous work is a reliance on retrospective questionnaires or laboratory-based designs (3,4). Although these methods provide valuable information, they raise concerns regarding memory biases and reporting accuracy on questionnaires, and questions about real-world generalizability for laboratory studies. Ecological Momentary Assessment (EMA) provides an alternative data collection approach that allows researchers to collect multiple assessments from people regarding current or very recent events or experiences, in their natural environment. The advantages of this method are discussed at length elsewhere (1), but in brief, EMA reduces memory biases, provides data more generalizable to real-world contexts, and allows for the assessment of dynamic processes. EMA methods have been used to study eating behaviors – primarily binge eating – and mood among women with bulimia nervosa (BN) and binge eating disorder (BED). Much of this work has developed as a means of testing theoretical models that posit that negative affect may play a critical regulatory role in the onset and maintenance of disordered eating behaviors (or eating behaviors more generally; e.g., 5). The affect regulation model suggests that binge eating is triggered by increases in negative emotions, and that the binge eating then serves to reduce these negative emotions (6). Various derivations of this model have also been developed that attempt to more carefully identify the mechanism whereby affect regulation occurs. For example, theories posit binge eating may serve as a way to distract oneself from negative emotions (escape from self-awareness; 7), mask the true causes of negative emotions (masking theory; 8), or replace one negative emotion (e.g., depression before binge eating) with a less aversive one (e.g., guilt after binge eating; trade-off theory; 9). In general, all of these affect regulation models assume that binge eating in response to negative emotions is maintained through negative reinforcement, and test two primary hypotheses: (1) binge eating is preceded by an increase in negative affect; and (2) binge eating results in a decrease in negative emotions. Several EMA studies have examined the mood antecedents and consequences of binge eating and found NA is higher prior to binge eating events, relative to either average NA or NA before regular eating (10-14). Findings regarding negative mood after binge eating episodes are inconsistent; some EMA studies report immediate post-binge increases in NA (11,15,16), whereas others find a decrease in NA in the hours after binge episodes (10,12,13). In studies that have examined NA relative to purging events (e.g., self-induced vomiting, laxative use), findings in women with bulimia show that NA increases in the time leading up to the purge, and decreases following the event (10,13). Substantially fewer studies use EMA to examine the relationship between mood and other disordered eating behaviors beyond binge eating and purging. Carels and colleagues have used real-time assessment methods to evaluate mood states that are associated with lapses in dieting among obese adults. Results have demonstrated that dietary lapses were significantly associated with concurrently feeling more sad or stressed at times when participants reported lapses in dieting (17,18). An EMA pilot study of patients with anorexia nervosa [AN] demonstrated that negative affect lability is associated with restrictive behaviors and rituals (19). These studies, however, did not evaluate the mood-behavior relationship at consecutive assessment points (i.e., before and after events) as has been done with binge eating and purging behaviors. Furthermore, there remains a dearth of information regarding the momentary relationship between mood and other disordered eating behaviors that are frequently seen in clinical and subclinical disorders. For example, the real-time assessment of mood and restrictive eating behaviors that are seen with many eating disorders (e.g., AN, BN) have not been studied beyond studies of dietary lapses (17,18) in non-eating disorder patients. In addition, although loss of control over eating is a component of binge eating, many studies operationalize binge eating as only eating a large quantity of food in a discrete period of time (16,20), and loss of control has not yet been evaluated independently. There is a similar lack of information examining mood-eating behavior processes in women who engage in unhealthy eating behaviors, but do not meet criteria for an eating disorder. Particularly among college-aged samples, research suggests that a substantial number of women engage in subclinical disordered eating behaviors. For example, in a study of 643 non-obese college women, although only 3% were classified as having bulimia, 61% were identified as having some form of disordered eating, such as chronic dieting, subclinical bulimia, or binging/purging alone (21). Other studies have similarly shown that more than a quarter (25.9%) of women age 18-22 report having bulimic episodes within the last month (22), and among college women, 16.3% reported they had binged, 10.3% had purged, and 18.6% had used laxatives, diet pills, or diuretics in the last 3 months (23). Although not at clinically diagnostic levels, these behaviors are potentially problematic because eating and weight-related concerns can significantly interfere with social and academic performance (23), and are associated with more negative body image, lower self-esteem, and depression (21,24). Given the high prevalence of disordered eating and the significant negative impact these behaviors can have on women, studies examining behaviors in these samples are warranted. Furthermore, because disordered eating behaviors are risk factors for the development of clinical eating disorders (e.g., 25), understanding the processes that may influence the onset or maintenance of these behaviors early on could be useful for informing intervention and prevention efforts. The goal of the present study was to provide a preliminary examination of the relationships between negative mood and a range of eating behaviors, as they are experienced in everyday life by young women with subclinical disordered eating. EMA methods were used to assess negative mood and disordered eating and weight control behaviors, including eating unusually large quantities of food, loss of control over eating, restricting food intake, and skipping meals to control weight or shape. The aims of this study were: (1) to evaluate whether higher levels of disordered eating behavior was associated with higher NA prior to the behavior; and (2) to determine if higher current NA was associated with reporting recently engaging in greater levels of disordered eating.