Consumers in Australian households contribute around 50 % of the economic value of food waste along the supply chain. Identifying effective food management behaviour change approaches is crucial to reducing this. Most food waste interventions are not evaluated, and those that are fail to take a baseline measure to identify changes. Further, it is important to identify if changes are enduring, or merely a temporary response to intervention. This paper fills this critical gap by evaluating 671 households in a randomised controlled trial (RCT) over seven months. This study implemented interventions, using principles of nudging and cognitive dissonance, to bridge the attitude-behaviour gap, measuring food waste and behaviours via online surveys. A longitudinal comparison revealed a general reduction in self-reported food waste among participants. In addition, those with higher amounts of food waste reported the largest reductions. Results support use of multi-touchpoint interventions, delivered in-home, to facilitate sustained food waste reductions.