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.