Hunger and binge eating: a meta-analysis of studies using ecological momentary assessment.

Binge eating represents a central behavioral feature of both Bulimia Nervosa (BN) and Binge Eating Disorder (BED) and is associated with distress and risk of future weight gain and obesity.1–4 Thus, it is important to identify factors that contribute to binge eating in order to prevent and treat this pernicious symptom. Previous research indicates that individuals with BN and those with BED report greater levels of hunger compared to controls on the Three Factor Eating or Dutch Eating Behavior Questionnaires,5–8 suggesting that greater physiological drive to eat may contribute to risk of developing disorders characterized by binge eating. In addition, individuals who binge commonly endorse hunger as a precipitant to their binge eating in retrospective reports.9–14 Thus, high levels of hunger may be implicated as an antecedent trigger of binge eating. However, results based on traditional research methods are associated with methodological limitations that constrain conclusions about the role of hunger in binge eating. Cross-sectional studies cannot assess temporal sequences of changes in hunger and binge eating necessary to establish hunger as an antecedent of binge eating. In addition, the accuracy of retrospective recall is questionable due to memory limitations15 and cognitive biases.16 To address these limitations, there are a growing number of studies examining hunger and binge eating using ecological momentary assessment. Ecological momentary assessment (EMA)17 takes place in participants’ naturalistic environments, supporting the ecological validity of this approach. In addition, participants make ratings of current psychological states and behavior, reducing concerns associated with retrospective recall. Finally, EMA involves multiple assessments over time, which allows for the temporal ordering of changes in hunger and binge eating behavior. Thus, EMA is an ideal method for testing hypotheses regarding transient changes in hunger and subsequent binge eating, and several studies have utilized this approach. However, conclusions drawn from these individual studies are somewhat limited by small samples within studies and correspondingly low statistical power which constrains ability to identify potential moderators of associations between hunger and binge eating. Moreover, no systematic review has been conducted of EMA studies examining associations between hunger and binge eating. Thus, the purpose of this review was to examine hunger as an antecedent to binge eating using a meta-analysis of EMA studies. A meta-analysis has the advantage of aggregating results across studies to increase statistical power. In addition, a meta-analysis allows for the examination of moderating variables, particularly those that vary across but not within studies. For example, studies have varied in sample characteristics (e.g., diagnosis) and methodology (e.g., duration of EMA), and these factors were systematically examined for their potential influence on the magnitude of associations between hunger and binge eating. Based on previous research, we hypothesized that hunger would be elevated prior to binge eating. Support for this hypothesis would provide further evidence for theoretical models that incorporate high levels of hunger as a trigger for binge eating and potentially explain the efficacy of treatment components for binge eating such as the prescription of regular eating and the use of selective serotonin reuptake inhibitors (SSRIs) as these influence appetite.