A behaviourally segmented assessment of the environmental, nutritional, and economic impacts of household food waste in the Republic of Ireland

of freshwater consumption. Calculated economic losses amounted to €82.8 /cap/year, equating to approximately €449 million nationally. Nutrient losses included 16,459 mg calcium, 2092 mg vitamin C, 363 g dietary fibre, and 170 mg iron per person annually. Red meat waste accounted for the largest environmental burden, while fruit, vegetables, and dairy products contributed most to nutrient losses. Behavioural segmentation revealed that High-Spending Disposers generated more than double the waste of Time-Conscious Savers. Scenario analysis indicated that a 50% behavioural shift from high-waste to low-waste clusters by the year 2030 could reduce national food waste by 19%, lower greenhouse-gas and land-use impacts by 31%, and cut annual monetary losses by €87 million. Study findings highlight the multidimensional nature of household food waste and its potential for synergistic mitigation across environmental, nutritional, and economic domains. Policy frameworks integrating behavioural interventions, nutritional framing, and circular-economy metrics are essential for achieving SDG 12.3 and advancing ROI's transition towards sustainable food systems.