Intervention effects of information and self-regulation on eating fruits and vegetables over two years

OBJECTIVE: This study tested whether an intervention that combined information with self-regulation strategies had a better effect on eating fruits and vegetables than an information-only intervention.

DESIGN: Women between age 30 and 50 (N = 255) participated in a 24-month randomized controlled trial comparing two brief interventions: All participants received the same information intervention; participants in the information plus self-regulation group additionally learned a self-regulation technique that integrates mental contrasting with implementation intentions.

MAIN OUTCOME MEASURES: Participants reported in daily diaries how many servings of fruits and vegetables they ate per day during 1 week at baseline, and in the first week, 1, 2, 4, and 24 months after intervention.

RESULTS: Participants in both groups ate more fruits and vegetables (0.47 to 1.00 daily servings) than at baseline during the first 4 months after intervention. Two years later, participants in the information plus self-regulation group maintained the higher intake, whereas participants in the information group returned to baseline levels.

CONCLUSION: Adding self-regulation training to an information intervention increased its effectiveness for long-term behavior change.