Ecological Momentary Assessment of Unhealthy Exercise and Affect in Eating Disorders
Over 30 million people in the U.S. have an eating disorder (ED), and almost four million people with an ED will die from ED-related health complications or suicide. Unhealthy (excessive) exercise is an ED symptom present in approximately 50% of people with EDs. When present, excessive exercise is associated with more severe ED psychopathology, slower rates-of-recovery, and faster rates-of-relapse. Moreover, although not a part of the diagnostic criteria for EDs, sedentary behavior may also be harmful as 50% of individuals with EDs have co-occurring overweight/obesity. In general population samples, sedentary behavior is associated with higher risk for mortality and health complications (e.g., diabetes, heart disease, etc.). If left untreated, individuals with EDs engaging in unhealthy exercise are at greater risk for negative physical and psychiatric health outcomes and excess mortality which, in turn, increase societal costs associated with healthcare utilization.
There is a critical need to use objective measures of physical activity in “real-time” across the weight spectrum in persons with EDs to understand the form, function, antecedents, and consequences of unhealthy physical activity (both excessive and sedentary). The scientific premise that guides the proposed research is that the identification of antecedents and consequences associated with unhealthy exercise among persons with EDs will lead to the development of personalized, just-in-time, mHealth interventions that can be sent to individuals with EDs anytime and anywhere.
As a first step toward testing our scientific premise, the objective of this study is to identify how different forms of unhealthy exercise function relative to temporal changes in affect. We will achieve our objectives through a 14-day ecological momentary assessment study of non-treatment seeking women with EDs (N=100). Participants will:
- wear a research-grade Actigraph to measure objective physical activity;
- take photos of meals/snacks using SmartIntake®, an image-assisted dietary recall smartphone App, to assess restricting, loss-of-control eating, and daily caloric intake; and
- respond to 4 daily, semi-random as well as event contingent (when exercise is present) prompts to measure levels of positive (PA) and negative affect (NA) as well as vigor and fatigue.
Specific aims include: 1) identify the frequency of different exercise patterns among women with EDs and 2) examine moment-to-moment antecedents and consequences of compensatory and restrictive exercise days among women with EDs using real-time assessments of affect and eating. As an exploratory aim, we will model the trajectory of PA, NA, vigor, and fatigue for all forms of unhealthy exercise. We aim to identify within-person (i.e., personalized) temporal relationships between affect and unhealthy exercise.
Knowing an individual’s triggers for impending unhealthy exercise will allow for individualized treatment efforts that do not take a one-size-fits-all approach. By closely monitoring triggers of unhealthy exercise and current physical activity (via smartwatches), automatic and tailored text messages could be sent to persons with EDs to intervene when disordered exercise has occurred or is likely to occur.