Few trials have investigated factors that moderate the effects of eating disorder and obesity prevention programs, which may inform inclusion criteria and intervention refinements. We examined factors hypothesized to moderate the effects of the Healthy Weight eating disorder/obesity prevention program that promotes gradual healthy changes, and Project Health that adds cognitive dissonance activities. College students at risk for both outcomes because of weight concerns (N = 364, 72% female) were randomized to these interventions or an educational video condition, completing pretest, posttest, and 6, 12, and 24-month follow-up assessments. Healthy Weight and Project Health produced significantly larger reductions in eating disorder symptoms versus video controls for individuals with higher negative affect, emotional eating, dietary fat/sugar intake, and perceived pressure to be thin. Project Health also produced significantly less increases in BMI versus video controls for individuals with lower negative affect. Results suggest that these interventions produce larger eating disorder symptom reductions for individuals at elevated risk for eating pathology but hint that weight gain prevention effects may be attenuated by elevated negative affect. Results imply that larger eating disorder symptom reductions will result when implemented with individuals with both weight concerns and one of the additionally identified risk factors.
Trial registration: ClinicalTrials.gov NCT01680224.
Keywords: Dissonance; Eating disorders; Moderators; Obesity; Prevention.
Copyright © 2019. Published by Elsevier Ltd.