Why and How to Measure Food Loss and Waste

Whole Supply Chain Approaches - Why and How to Measure Food Loss and Waste


A whole supply chain approach encompasses all stages in the food supply chain. This includes all activities and destinations from production to final consumption or disposal. A user of this approach would be national and local governments. A useful application of this approach would be to analyze flows of specific food products or food categories across the entire food supply chain. Such an approach can provide insights into material flows, food availability, environmental impact, food waste hotspots and opportunities for waste prevention, disposal methods, production and consumption trends, and so on. A different user could vary the working definition of FLW by adjusting the scope of their analysis to focus on specific aspects of the food supply chain.

FLW can be generated for a variety of reasons throughout the supply chain, and the user is recommended to review the relevant modules in this guide for details at each stage. Interventions are often tailored to a stage in the food supply chain with a sector-specific perspective because both existing data and direct measurements tend to occur at the sectoral level.

In addition to the methods listed in Table 15, national governments may find the Food Loss Index and Food Waste Index to be useful tools. These indices, developed by the United Nations, estimate FLW within a country based on existing data relating to key commodities within a country.

Table 15. Methods Used to Measure FLW across the Whole Supply Chain

Method Name Direct FLW Access Needed? Level of Accuracy? Level of Resources Required? Tracks Causes? Tracks Progress Over Time?
Methods for gathering new data
Interviews/Surveys No Low-Medium Medium-High Yes Yes
Methods based on existing data
Mass Balance No Medium Low No Yes
Proxy Data No Low Low No No
Records No Variable* Low No Yes
Less commonly used methods across the whole supply chain
Diaries No Low-Medium Medium Yes Yes
Direct Measurement Yes High High Yes Yes
Waste Composition Analysis Yes High High No Yes

*Accuracy depends on the type of record used: for example, waste transfer receipts may be highly accurate for determining FLW levels, whereas other records are less accurate.
Note: The methods named are nonexhaustive.
Source: Authors.

Case Study for Measuring across the Whole Food Chain

The US Department of Agriculture (USDA) Economic Research Service (ERS) estimates all post-harvest losses through the entire food supply chain for over 200 agriculture product types through its Loss-Adjusted Food Availability Data Series. This data series helps the USDA ERS produce estimates of loss-adjusted food availability as a proxy for food consumption. To create this data series, the USDA ERS developed loss coefficients, updated primary conversion factors and compared shipping and point-of-sales data. By estimating food losses in the United States with such a high level of accuracy, the USDA ERS helps US state and local governments, food industries, nongovernmental organizations and others identify opportunities to prevent FLW. These estimates allow others to identify hotspots in which to conduct more detailed research with the aim of preventing FLW (Buzby et al. 2014).