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5. The Art of Measuring and Evaluating

The most important question to ask before embarking on a measure is what the measurement data will be used for. While this sounds trivial, in today’s society, vast amounts of data are measured without any thought as to how they will be used. This also means that substantial resources are spent on something that does not generate significant benefit.

5.1 Why measure?

We can exemplify the need to measure by the example of waste in households. Through so-called pick analysis studies, where household food waste is sorted, one can get a good picture of how much is thrown away (except for liquid waste), including the most common categories of food. If the goal is to know how much is thrown away, this is a good measurement method, albeit resource-intensive. Nevertheless, if the goal is to understand which measures can reduce FLW, then not much information is provided – we only know what was thrown away, not why. Moreover, pick analysis studies provide aggregate values for residential areas. However, how much and what is thrown away varies greatly between households. This mean that there is a need for a range of measures. In summary, measurements of aggregate quantities provide a poor basis for designing effective measures.
To get a good basis for designing measures, more fine-grained information is needed, especially about why food is thrown away. Behind every piece of food that is thrown away is an individual decision. This decision can be traced to everything from attitudes to legislation, often in combination with different factors. If much of the focus of measurements so far has been about defining and quantifying the amount of FLW (which remains unfinished), more measurement and evaluation are now needed to understand why individuals throw away food. What makes the stressed mother of young children repeatedly find mouldy food in the refrigerator; what makes the shop employee throw away food in the store; what makes the machine operator in the food industry have to throw away parts of the production? All these decisions depend not only on attitudes and knowledge but also on conditions in the systems around individuals. What conditions govern decisions, and how can the conditions be changed? An understanding around the conditions governing decisions will enable much better opportunities to design effective measures.
In summary, to design effective measures to reduce FLW, more detailed information is needed about what is thrown away and why.

5.2 What is thrown away – and how much?

The definition of what constitutes FLW has varied over time and between organisations, and there is still no consensus on the concept. Within the UN, the responsibility for food loss has been divided between the FAO, which is responsible for food waste up to trade, while UNEP is responsible for food waste from trade and later on in the value chain. The reason for the division seems primarily to have been to adapt the concepts to the ways in which each organisation measures FLW.
The EU’s definition of food waste has also evolved,
Guidance on reporting of data on food waste and food waste prevention according to Commission Implementing Decision (EU) 2019/2000. https://ec.europa.eu/eurostat/documents/342366/351811/Guidance+on+food+waste+reporting/5581b0a2-b09e-adc0-4e0a-b20062dfe564 (2024-08-14)
and it is this that the Nordic countries have to relate to in their reporting. However, there are possibilities for interpretation, and in some cases, there is every reason to include areas in food waste work that are not included in the EU definition. For example, only food that is thrown away after harvest or slaughter is included in the definition. This means that fully edible carrots that are ploughed back into the fields for economic reasons are not reported as food waste nor are animals that die during transport to slaughter or old laying hens that are culled and thereafter destroyed.
Food loss (FAO)
Food waste (FAO)
Households
Primary production
Food industry
Wholesaler
Grocery store
Pre harvest/
Pre slaughter losses
Restaurants/Public kitchens
Unharvested crops and animals dying on farm
Food losses
Food or by-products that become fodder, left in the field or for the grower's own biogas plant
Food Waste (EU)
Food that has become waste (normally goes to a waste facility) according to EU 2008/98
Figure 2: Concepts and definitions of food waste: food loss and waste from the FAO and EU.
The Swedish board of agriculture. 2024. Slutrapport om livsmedelsförluster. Resultat och åtgärder för att mer ska bli mat. https://www2.jordbruksverket.se/download/18.23e68dd418d7c649d1713a30/1707493705544/ra24_1.pdf (2024-08-14)
Furthermore, there is also food that while produced for human consumption is used for animal feed. Here, there is variation in terms of whether or not these food flows are included in calculations of FLW. It also varies whether only the edible part of the food is included in the statistics or whether inedible parts are also included. In addition, there are varying views on what is edible and what is not.
Consequently, there is a need to develop common definitions of what should be measured to get a better quantitative picture of what and how much is thrown away. Extensive work has been done in various Nordic countries. Since 2018, Luke in Finland has been working on this issue. Likewise, Norsus and Matvett in Norway have worked systematically to produce statistics and good ways of measuring that can map and compare FLW for different actors over time. Reports highlight difficulties around this undertaking and that many external factors and actors play a role.
A. Stensgård, K. Prestrud, P. Callewaert, and G. Booto. 2021. Sektorrapport for matbransjen, offentlig sektor og husholdingsleddet. ISBN 978-82-7520-873-4. https://norsus.no/wp-content/uploads/OR.36.21-Sektorrapport-for-matbransjen-offentlig-sektor-og-husholdningsleddet.pdf?v=1
For example, the pandemic shifted consumption, where more people cooked and ate food at home than normal. In addition, the EU and Eurostat have published guidelines on how food waste should be measured and followed up for increased comparability between countries. This work could be better coordinated between the Nordic countries to avoid duplication and produce more comparable data.
Nordic Council of Ministers. 2021. Monitoring Food Waste and Loss in the Nordic Region. Definitions, methods and measures for prevention. https://pub.norden.org/temanord2021-504/
At the same time, a lack of quantitative information is not the biggest obstacle to designing and implementing effective measures to reduce FLW. Above all, more knowledge is needed about why food is thrown away (and the courage to take on board the implications of the knowledge).

5.3 How to understand why food is thrown away

As mentioned in the previous chapter, there are many reasons why food is thrown away. Later chapters will describe in more detail the causes within the different stages. There is a great deal of knowledge about why food is thrown away, but it is an area that currently needs to be explored to a much greater extent. However, it is not an entirely simple area; it is also interdisciplinary, since knowledge in everything from behavioural science to economics and legislation may be needed, and partly because it is about one of the most difficult phenomena to study – what happens in the human brain.
To understand why individuals decide the way they do, we need to follow their behaviour and interpret it alongside interview data. There are many difficulties in obtaining accurate data. First, individuals need to agree to participate. An important aspect is the significant bias owing to the probability of overrepresentation of engaged individuals.
V. Amicarelli and C. Bux. 2021. Food waste measurement toward a fair, healthy and environmental-friendly food system: a critical review. This study critically reviews food waste measurements, focusing on the stages from agricultural production to retail, including Sweden among other countries.
Those who do not care about FLW rarely participate. Second, most people are influenced by their participation in a study (e.g. people want to behave in ways they perceive to be correct), and few people believe that it is okay to throw away food. Both interview responses and behaviour are influenced in an undesirable way. In a diary study, it was observed that respondents threw away more food at the end of the week, as they had become aware of their behaviour.
H. Williams, J. Trischler, F. Wikström, and Z. Rowe. 2020. Avoiding Food Becoming Waste in Households – The role of packaging in consumers´ practices across different food categories. Journal of Cleaner Production, Vol. 265.
Third, respondents may be unaware of the real reason why they throw away food. For example, the reason for throwing out sour milk from the refrigerator could be that the package was too large for the household’s needs, but the respondent might think that the cause is their own behaviour, that is, that they bought too much.
Similarly, it can be difficult to trace why the shop employee throws away food. Is it because the central management of the business chain is pushing for campaigns? Could it be a poor work environment that generates high staff turnover and low engagement? Is there a lack of commitment from the shop owner/manager on the issue? Answering these questions requires respondents who want to offer their time to provide answers, which in turn requires trust that the answers will not affect them negatively. One can assume that in most cases those who participate have their own commitment to the FLW issue, which can bias the results. However, it is the best that can be achieved – we simply have to be aware that the results will not be representative of the whole.
To really understand the causes of FLW in depth, we recommend more studies where researchers participate in daily operations and can observe and ask individuals about the reasons for their behaviours. This closeness would facilitate insights that cannot be uncovered in other types of studies.
Before measures are implemented, the causes of FLW should be mapped. If FLW can be traced to the fact that it is the lowest economic cost to throw away food compared to other measures, then the measures need to be directed towards changing the economic incentives rather than influencing attitudes and behaviours. The better the knowledge of the causes, the greater the chance of designing effective measures.

5.4 Measuring the effectiveness of measures

A great deal of measures is being taken to reduce FLW, but very rarely are they evaluated in a way that allows one to assess their effectiveness. During the work on this report, we sought to identify measures implemented in the Nordic countries, where the effects thereof on FLW have been evaluated in order to find good examples. Unfortunately, it was difficult to find such examples. Whether this was because of a lack of evaluations or because they have not been documented, we do not yet have the answers. It can also be difficult to determine whether the figures highlighted are due to FLW being moved to another actor. For example, if the reduction is mainly due to food being donated instead of thrown away and there is no follow-up on how much of the donated food is thrown away after all, the effectiveness of the measure would remain unclear. Food that becomes raw material for new products reduces waste, but as mentioned earlier, this alternative is considerably worse from an environmental point of view than measures geared towards human consumption directly.
A number of variables can be evaluated.
C. Patinha Caldeira, V. De Laurentiis, and S. Sala. 2019. Assessment of food waste prevention actions, EUR 29901 EN, Publications Office of the European Union, Luxembourg.
We highlight a couple below:
Efficiency: how change was achieved per resource invested. Change can be measured in the amount of reduced FLW, changed attitudes, reduced environmental impact, social effects or whatever was the goal of the measure. Invested resources can be economic investments in time, technical equipment, the environmental impact of invested resources, etc.
Sustainability over time: the result of a measure can be limited over time. For example, informing students about the environmental consequences of FLW can lead to reduced waste. With time, the effects fade, and new students who have not received the information start school. Similarly, staff training efforts can fizzle out over time with high staff turnover.
To evaluate measures and increase learning about effectiveness, more time often needs to be spent in the planning phase. What is to be achieved? Is more knowledge needed about the causes of waste? How should the measures be evaluated?
More well-planned and evaluated measures are needed to sift through effective measures. Here, authorities and public operations have an important responsibility. Better documentation is also needed to spread information about experiences and increase learning.
With this said, measurement requirements should not be increased ad absurdum. The requirements to measure and report generally unnecessarily burden many operations. For example, the Stockholm region has been criticised for forcing nurses to measure FLW instead of spending time on patient care.
H. Kjöller: Ska undersköterskor leverera underlag till powerpoint – eller vård? Ledare i Dagens Nyheter 2023-05-15. Sverige. https://id.bonniernews.se/login?returnUri=https%3A%2F%2Fwww.dn.se%2Fledare%2Fhanne-kjoller-ska-underskoterskor-leverera-underlag-till-powerpoint-eller-vard%2F (2024-06-10)
The article, written by a nurse, testifies to the importance of measures being perceived as meaningful by those affected. There needs to be a balance between targeted and well-thought-out initiatives for systematic learning as well as more free initiatives where one can work their way forward in accordance to their specific context and situation.