Promoting public participation in reducing food waste: A large-scale multiple randomized controlled trial

Interventions on consumers food waste behaviour are an effective way to reduce food waste as well as negative environmental impacts. Informational interventions dominate the current field interventions, while large-scale consequence and integrated interventions are less available. In this study, a 5-month long multiple randomized controlled trial was conducted on 2524 customers in the food service industry in China. The study used a propensity score matching method to evaluate the effects of single informational (instructive vs guilt vs coupled), financial (rewards vs penalties) interventions, and integrated interventions (informational and financial) on reducing food waste. Utilising the principles of the Persuasion Effect, Prospect Theory, Expected Utility Theory, and Level of Explanation Theory, it was found that the informational intervention resulted in a 23% (10.69g) reduction in food waste (Study 1). The high-intensity financial intervention reduced food waste by 43% (12.43g) (Study 2). The integrated intervention reduced 27.72g (27%) (Study 3). Also, the intervention revealed noteworthy distinctions among the cohorts of consumers regarding their gender, age, meal expenditure, and BMI. This study establishes the efficacy of informational intervention, identifies the most suitable type and intensity level of financial interventions, and presents an efficient form of integrated interventions.