Efficacy of informational intervention on food waste: Evidence from a randomized controlled trial

Interventions on consumer food waste behaviours are an effective way to reduce food waste as well as negative environmental impacts. Informational interventions are currently popular. However, the effectiveness of informational interventions is controversial and has not been evaluated on a large scale in practice. This study tested an 11-week randomized controlled trial in the food service industry covering 11 types of food waste and consumption, using a propensity score matching method between experimental (N = 712) and control groups (N = 591) to assess the effectiveness of different types of information (instructive VS guilt-based VS coupled) interventions. It was found that there was a significant reduction of 10.69g (10%) in the total amount of food waste after the informational intervention. Instructive information had a significant impact on food waste reduction, reducing 20% of waste at the consumption stage, followed by guilt-based (4%) and coupled (3%) information. The instructive-type intervention was found to be the most effective for reducing waste in pork, roots and tubers, cereals, and legumes, while the guilt-type intervention was found to be the most effective for reducing waste in eggs. Differences in terms of consumers' gender, education, weight, and amount spent were confirmed. In addition, the informational intervention had a spillover effect on food consumption, with instructive information significantly increasing food consumption by 23.82g (37%). This study shows that informational interventions, especially instructive information, are effective and reveals differences between segments. It also emphasizes the significance of considering the type of information and food categories for both the food service industry and national interventions.