Epsilon Archive for Student Projects

Abstract

Having significant impacts on the environment, societies, and economies all over the world, the global food system is linked to many challenges related to sustainable development. Food waste constitutes one problem area within the food system where approximately one-third of all food produced gets lost or wasted along the supply chain. Households constitutes one of the largest contributing groups to the global food waste. Reducing food waste at the later stages of the supply chain, including households, is an acknowledged solution to mitigate the negative impacts of the global food system. To reduce food waste, there is a need to have a monitoring system in place since this allows for both an understanding of the current situation as well as a possibility to evaluate the efficacy of food waste-reducing interventions. There are several methods available for quantifying household food waste that each come with their advantages and disadvantages related to e.g. costs, workload and reliability. This study presents a comparison of household food waste quantities when applying different quantification methods. The different methods that are compared are smart bin (where the organic waste bin is placed on a scale that records waste as it occurs), and questionnaire (where the households are asked to estimate their food waste retrospectively) from four households in Uppsala (Sweden) The smart bin data was collected from four households in Uppsala, Sweden, that had been using the smart bins for one year, the questionnaire data were collected from the same households for three weeks. The result from the smart bins and the questionnaire is then compared to national and local statistics collected through waste composition analysis (municipal organic waste is quantified after being sorted and categorised at the waste collecting centre).
The study result shows a significant difference in household food waste quantities between the different quantification methods. On average, the questionnaire registered an average food waste quantity that was 0.85 kg or 57% lower than the average waste recorded by the smart bins during the same period. In a similar manner, the smart bins revealed an average waste that was 43% lower than the national average household food waste quantified by using waste composition analysis. There are several possible factors identified to have influenced the difference in food waste quantities, for instance, demographical factors and errors related to the selected methods. Additionally, the questionnaire method was found to be associated with underreporting and human error when using it for quantifying food waste, giving room for improvements. Instead, the results suggest that the smart bins are to be preferred over questionnaires for quantifying household food waste. However, in order to obtain a more generalisable result a larger sample with a greater demographical spread is required, which can be more costly and require more technical expertise if using smart bins. Further research to develop and apply adequate methodology on household food waste accounting is an essential step in the quest towards reaching a sustainable food system with less food waste.