Automated tools for waste quantification hold promise in providing preciser understanding of food waste. This study evaluated a tool to quantify plate waste in primary school canteens. It encompassed data from 421,015 instances of food wastage. The evaluation revealed high accuracy, with the tool's plate waste detection falling within ±10% of manual recordings. However, the tool estimated 40% fewer individual guests compared to manual entry due to not all students wasting food. As a result, the automatically collected data indicated a 35% higher waste-to-guest ratio. The findings showed that a minority of students (20%) accounted for a majority (60%) of plate waste. Halving the waste generated by this group would reduce overall plate waste by 31%, emphasizing the importance of tailored interventions for high-profile wasters rather than applying general measures to all students. Targeting areas with the greatest potential can contribute to a more sustainable food system with reduced waste.

Retailers' food waste, often consisting of edible food, could be reduced, while simultaneously tackling food insecurity, through surplus food donations to vulnerable groups. However, sustainability assessments of food donations covering all three sustainability perspectives are scarce, hampering decision-makers in prioritizing donation as a food waste management measure. This Swedish case study assessed the environmental, economic, and social aspects of surplus food donation and examined trade-offs between the different sustainability perspectives. Methods included life cycle assessment, net economic benefit calculation, social life cycle assessment based on food security questionnaires, and nutritional assessments. The results showed that food donation was a way to reduce food waste benefitting the environment and adding economic and social value, to vulnerable people in particular. Despite substantial rebound effects offsetting some potential environmental savings, food bag donations outcompeted anaerobic digestion as a food waste management option in terms of environmental mitigation effect. Regarding trade-offs, accrued savings causing the rebound effects generated important social value for the donation recipients, by relieving their personal finances. Private and public investment was required to fund the donation units, but positive economic value was generated through valorization of surplus food. Food bag donations also showed potential to alleviate recipients' food insecurity and to contribute positively to recipients' nutrition intake. To realize the potential of surplus food donation, policy measures should be better aligned with the waste hierarchy. Despite some trade-offs and inability to solve the underlying problems of food insecurity, food donations have great short-term potential to contribute to a more sustainable society.

There is a preconception among kitchen staff that the most popular school meals drive food waste in Swedish school catering and that vegetarian dishes increase food waste, despite being less popular than meat options. By applying mixed methods, this study investigated possible goal conflicts between reduced food waste, high acceptance, and vegetarian options on the lunch menu. An overall aim was to gain knowledge on how lunch menus could be adapted for increased sustainability. Kitchen staff from 10 Swedish primary and secondary schools were interviewed to identify the most popular and unpopular meals, and food waste quantification data and lunch menus from 61 school canteens were analyzed. The results showed that, while the common perception of popular and vegetarian meals creating most waste was held by kitchen staff, it proved to be untrue. In fact, popular school meals and vegetarian options generated less waste than unpopular meals. A vegetarian paradox was detected in interviews, with vegetarian options considered unpopular but with several vegetarian options among the most popular dishes. Thus, school-catering units should stop serving unpopular meals and shift their focus to serving popular nutritious meals, including popular plant-based options, as part of efforts to make school meal schemes more sustainable.