Objective: To compare the effectiveness of messages emphasizing the importance of either personal or social responsibility for dietary behavior change in increasing fruit and vegetable intake.
Design/setting: Randomly assigned individually or socially oriented messages were delivered at baseline, 1 week, and 2 and 3 months later. Telephone surveys were conducted at baseline and 1 and 4 months later.
Participants: 528 callers to a cancer information hotline who were not meeting the "5 A Day" dietary recommendation.
Interventions: A brief telephone-delivered message and 3 mailings of pamphlets and promotional items encouraging fruit and vegetable intake that emphasized either personal or social responsibility.
Main outcome measures: Fruit and vegetable intake 1 and 4 months post baseline.
Analysis: Chi-square, t tests, and analyses of variance and covariance.
Results: Both types of messages increased intake substantially (P =.01). To some extent, the social responsibility message continued to motivate increased intake over time compared with the personal responsibility message.
Conclusions and implications: These minimal interventions had a substantial impact on fruit and vegetable intake. Health messages might be more effective over the longer term if they are designed to emphasize the importance of social responsibility, although further study is needed to confirm the robustness of these findings.