Background: Research on coaction suggests improvements in physical activity and emotional eating will occur in a reciprocal manner. Aims: To determine if changes in body satisfaction mediate relations between physical activity and emotional eating changes and if age affects degree of change in those variables. Method: Groups of early adult (n = 43) and middle-age (n = 52) women participants of a community-based obesity treatment were assessed on behavioral and psychological variables over 3 and 6 months. Results: Improvements in physical activity, anxiety-related emotional eating, body satisfaction, anxiety, and exercise self-efficacy were significant overall. Early adults demonstrated greater reductions in emotional eating. Physical activity increase over 3 months significantly predicted 6-month reduction in emotional eating but not vice versa. Body satisfaction change significantly mediated the physical activity--emotional eating relationships. Changes in anxiety and exercise self-efficacy moderated activity [right arrow] emotional eating and body satisfaction [right arrow] physical activity relationships, respectively. Conclusion: Findings can inform both theory and behavioral obesity interventions.