Using social norms to encourage healthier eating

What and how much people choose to eat is influenced by social context. People tend to use the eating habits of others as a guide to appropriate consumption. This suggests that one way of encouraging healthier eating would be to provide information about the healthy eating choices of others. Research conducted as part of an Economic and Social Research Council-funded project investigated the effect of providing information about how others eat on the purchase and consumption of vegetables in both laboratory and in field settings (restaurants). In a laboratory-based study, we found that that while overall vegetable intake was not increased, exposure to a novel 'liking norm' message increased the selection and intake of broccoli from a buffet by participants who were low habitual consumers of vegetables. We also found that the liking norm increased broccoli intake even when there was a delay between exposure to the message and selection at the buffet, suggesting that the effects of social message exposure may persist beyond initial exposure. In two online studies and a laboratory study, we found that the effect of exposure to a descriptive social norm message on eating intentions and intake was moderated by the participants' motivation to identify with the norm referent group. In three intervention studies, exposure to social norm messaging was associated with increased purchases of meals with vegetables in restaurant settings. Taken together, these results suggest that it is feasible to use social norm messages in restaurant settings and they provide information that could be used to implement randomised controlled trials.