Food waste: Disapproving, but still doing. An evidence-based intervention to reduce waste at household

This action-research project conducted in partnership with French local public authorities aims at designing an intervention procedure to reduce food waste in households. To broach the complex problem of food waste reduction as a behavioral gap, we compared three interventions: a classical information-based intervention, an awareness-based intervention using a kitchen diary to make people aware of their own waste, and a dissonance-based intervention using principles of cognitive dissonance. Behavioral changes were estimated by weighing food waste and analyzing them (compositional analyses) one week before and after the interventions, and also five weeks later in order to comprehend middle-term effects. Results showed that dissonance-based intervention was the most efficient in actually reducing food waste, but only within a middle-term perspective. This delay could be necessary given the behavioral complexity of the global act of "reducing food waste", known as the result of multiple and interacting activities taking place at different times and in different contexts.