Motivational Text Message Intervention for Eating Disorders: A Single-Case Alternating Treatment Design Using Ecological Momentary Assessment.

Objective: This study tested a motivational text message treatment adjunct for individuals with eating disorders (EDs) who exhibited high dietary restraint/restriction.

Method: A replicated single-case alternating treatment design was used to examine (a) the feasibility of combining a brief motivational interview with subsequent text messages and (b) the influence of the text messages on eating behaviors and motivation to change in individuals with EDs (N=12). The protocol was 8weeks and the text messages were adjunctive to cognitive-behavioral therapy.

Results: The intervention was well accepted (mean rating=7/10) and feasible within the context of monetary compensation (mean daily monitoring compliance =91%). Text messages did not impact behavioral outcomes: dietary restraint and kilocalorie intake. They had mixed effects on motivation to change dietary restraint, measured by the Readiness and Motivation Questionnaire (RMQ). When receiving text messages, RMQ precontemplation scores (desire to restrict) significantly increased, indicating decreased motivation; however, action scores (effort toward reducing dietary restraint) significantly increased, indicating increased motivation. These effects were moderated by weight status. Underweight individuals (n=4; body mass index [BMI]<19.0) reported increased ambivalence-that is, an increased desire to restrict and increased action toward reducing restriction-in response to the text messages. Normal weight participants (n=8; BMI>19.0) reported only increased action toward reducing restriction in response to the text messages.

Discussion: These data demonstrate text messages are a potentially feasible and acceptable treatment adjunct and may be effective at increasing motivation to change for normal weight individuals, while their influence on underweight patients is more complex. These findings provide a foundation for future research in technology-based motivational interventions for EDs and offer preliminary evidence for using these methods among normal weight individuals.