Prompting healthier eating: testing the use of health and social norm based messages.

OBJECTIVE Health based messages are commonly used to promote fruit and vegetable intake, but are limited in their effectiveness. Social norm messages, which suggest other people are eating healthily, may be more effective. Our aim was to compare the effect on food selection of a message containing health related information about fruit and vegetable consumption with a message containing social normative information about consumption of fruit and vegetables. METHOD In two laboratory studies, predominantly young female adult students were exposed to a health or social norm message about fruit and vegetables. In Study 1, lunch meal food selections and intake were assessed and in Study 2, snack food selections and intake were assessed. Study 1 examined the effect of a descriptive social norm (information about what others are eating) versus a health message and Study 2 examined the effect of both a descriptive norm and an injunctive norm message (information about what others approve of) versus a health message. RESULTS In Study 1, exposure to a descriptive social norm message resulted in significantly more vegetables being selected and eaten than exposure to a health message. In Study 2, exposure to a descriptive social norm message resulted in significantly more fruit and vegetables and less high energy dense snack food being selected and eaten than exposure to a health message. There was no effect of exposure to the injunctive norm message. In both studies, significant differences between the social norm and health message conditions were observed in low but not high usual consumers of fruit and vegetables. CONCLUSIONS For the promotion of healthy eating, social norm messages may be more effective than health messages for consumers failing to adhere to dietary guidelines.