Stop Waste Heroes - Measuring food waste in households and educating communities through schools to accelerate behavioural change
The Stop Waste Heroes project (Measuring food waste in households and educating communities through schools to accelerate behavioural change, Project No. 101217063) was implemented from July 2025 to August 2026 as a 14-month EU co-funded initiative. The project addressed household food waste through an integrated approach combining direct measurement, environmental education, digital monitoring, personalised feedback and practical prevention guidance, with primary-school pupils acting as a bridge between schools and their families. Its central premise was that food waste becomes easier to understand and prevent when it is made visible, measurable and personally relevant.
Project approach and implementation
The project was implemented by three partners with complementary expertise: VOUDOURI D. & SIA EE, responsible for project coordination and logistical support; the Hellenic Society for the Protection of Nature (HSPN), contributing its experience in environmental education and the Eco-Schools network; and SOTIRIOS MYLONAS & SIA EE, responsible for adapting the STOP-WASTE App to household use and data analysis. Activities were organised through four Work Packages covering
project preparation and coordination, initial measurement, the main awareness and educational intervention, and final measurement and evaluation.
The methodology created a practical behavioural cycle of “separate – weigh – record – learn – change – measure again.” Participating households received a standardised Stop Waste Heroes package containing a Bluetooth kitchen scale, a ventilated food-waste collection bin and compostable bags, a separate weighing container and biodegradable paper bags, printed guidance and an individual account in the STOP-WASTE App. The App and associated Web Panel enabled food-waste
measurements to be recorded, monitored and analysed directly. Waste was classified both by cause of generation—expired or spoiled food, meal leftovers and food preparation—and by seven food categories, providing information on how much food was discarded, what was discarded and why.
Before full-scale implementation, the methodology was pilot-tested with ten households under real household conditions, allowing the equipment and the written instructions to be tested and refined before procurement and wider deployment. Schools were subsequently selected and, following the signing of the relevant participation consent form by parents or guardians, pupils, teachers and households introduced to the project. The first measurement period established the baseline, after which results were returned to participants and combined with practical guidance and school-based educational activities. A planned visit to an organic-waste treatment facility was replaced by a safer and more accessible approach in which three small-scale organic-waste processing devices were brought into participating schools for practical demonstrations. Households then completed a second measurement period using the same methodology and equipment.
Key results
The principal quantitative result was a clear reduction in household food waste between the two measurement periods. The weighted daily average per household decreased from approximately 0.714 kg/day to 0.602 kg/day, corresponding to a reduction of 15.7%. Annualised, this represents a decrease from approximately 260.5 kg to 219.6 kg per household, while estimated annual food waste per person fell from 68.6 kg to 57.8 kg. Importantly, all eight participating schools recorded a lower weighted daily average during the second measurement period, although the magnitude of improvement differed considerably between schools.
The composition of food waste also changed in ways relevant to prevention. Expired or spoiled food decreased from 16.3% to 12.5% of measured food waste, while meal leftovers also became less prominent. Both categories are particularly important because they are closely associated with potentially preventable waste and household practices such as purchasing, storage, timely consumption, portion management and the use of leftovers.
A further important finding concerned the gap between perceived and actual food waste. Initial household estimates substantially underestimated the quantities subsequently revealed through direct weighing. Participants themselves identified the actual quantities discarded and the discrepancy between perception and measurement among the most striking findings of the project. This supports one of the project's main methodological assumptions: measurement was not only a data-collection
mechanism, but also an awareness-raising intervention in its own right. Feedback based on households' actual measurements helped transform food waste from an abstract environmental issue into a tangible aspect of everyday behaviour. The presentation of first-period findings was rated highly by 91.8% of respondents, while 87.5% gave similarly high ratings to the information and practical food-waste reduction advice provided.
Knowledge, attitudes and behavioural change
The project's evaluation activities provided complementary evidence of learning and behavioural engagement. The Final Quiz was completed by 135 households and produced an average score of 11.94 out of 15 (79.6%), indicating a generally high level of understanding of food-waste impacts, prevention and management.
The findings also showed improvement in specific areas where the initial questionnaire had identified knowledge gaps, including the interpretation of food date labels. More broadly, household evaluations indicated high levels of satisfaction with the project, strong acceptance of the practical prevention guidance and substantial self-reported changes in everyday food-management practices.
These findings, considered alongside the measured reduction in food waste, provide complementary indications that the intervention succeeded not only in raising awareness but also in encouraging participants to reconsider everyday practices related to purchasing, storage, preparation, consumption and disposal.
Teachers and participating schools similarly evaluated the project very positively. Their feedback confirmed the value of combining school-based environmental education with practical household action and highlighted the critical role of teachers in maintaining pupil motivation, connecting activities with the curriculum and facilitating communication between the project and participating families. Schools also identified opportunities for improvement, including stronger and more structured parental engagement, adaptation of some activities to pupils' developmental level, implementation in smaller groups, additional preparation time, greater networking between schools and the possible introduction of motivational or gamification elements.
Main lessons learned
Implementation demonstrated that a relatively complex household measurement methodology can be made accessible when supported by appropriate pilot testing, simple equipment, clear instructions, digital recording and readily available self-support resources. The STOP-WASTE App and Web Panel played a central role by integrating data collection, monitoring and analysis while allowing participants to carry out measurements with a high degree of autonomy.
The project also demonstrated the particular value of the school–household model. Children can act as effective knowledge multipliers, bringing environmental learning into the home and involving other household members in practical action. At the same time, sustained family participation cannot be assumed: variations in engagement and household retention highlight the importance of continuous communication, teacher involvement and stronger mechanisms for maintaining parental
participation.
The results should nevertheless be interpreted in light of the methodological limitations identified in the report. Participation was voluntary, household participation was not fully consistent throughout the project, no control group was included, and the participating households cannot be considered statistically representative of the wider Greek population. These factors mean that the observed changes should be regarded as strong evidence of promising change associated with the intervention
rather than definitive proof of causality.
Future applications would benefit from stronger differentiation between avoidable and unavoidable food waste, longer-term follow-up, more systematic behavioural indicators and, where feasible, inclusion of a comparison or control group.
Overall conclusion
Overall, Stop Waste Heroes provides a promising and potentially replicable model for linking environmental education with measurable household food-waste prevention. Its principal innovation lies not in any single educational or technological component, but in their integration: pupils learn about food waste; families measure their own behaviour; digital tools convert those measurements into usable data; actual findings are returned to participants; practical solutions are introduced; and
households are then given the opportunity to measure again.
The project recorded reductions in the main food-waste indicators, positive changes in the composition of waste, high levels of participant satisfaction and encouraging evidence of increased knowledge and self-reported behavioural change. Most importantly, it demonstrates that household food-waste prevention can become more actionable when people are not simply informed that food waste is a problem, but are enabled to measure their own waste, understand what the measurements reveal, identify why waste occurs and apply practical measures to reduce it. The experience and evidence generated by Stop Waste Heroes project therefore provide a sound basis for replication and larger-scale testing with a strengthened evaluation framework.