Why and How to Measure Food Loss and Waste

Primary Production - Why and How to Measure Food Loss and Waste


The primary production stage of the supply chain encompasses agricultural activities, aquaculture, fisheries and similar processes resulting in raw food materials. This first stage in the chain includes all activities related to the harvest, handling and storage of food products before they move to either processing or distribution. Any level of processing of raw food products does not fall within this stage of the supply chain but would rather be classified as processing and manufacturing.

Examples of primary production activities are: farming, fishing, livestock rearing and other production methods.

Food losses in primary production can be caused by many factors, including but not limited to: pests or adverse meteorological phenomena, damage incurred during harvest, lack of proper storage infrastructure, cosmetic or size requirements or economic or market variability (i.e., cancellation of orders, rigid contract terms, price variability or high labor costs).

The following nonexhaustive, illustrative list shows ways to prevent FLW during primary production.

  • Work with actors downstream in the food supply chain to increase the share of second-grade products that are accepted and valorized to some point.
  • Improve cold-chain management and infrastructure to prevent spoilage or degradation during storage and transport.
  • Work with actors downstream in the food supply chain to expand value-added processing to increase the proportion of produced food able to eventually be consumed.

Methods Used to Measure FLW

Appropriate methods for FLW measurement depend on the context of who is doing the measuring and what information is available. Start by answering the five questions below.

  • Do you have direct access to the FLW? Does the method require the ability to directly count, handle or weigh the FLW?
  • What level of accuracy do you need? How accurate will the data gathered with this method be?
  • What amount of time and resources can you assign to measuring FLW? The relative amount of resources (time, money, equipment) needed to carry out the method.
  • Do you need a method that can tracks causes of FLW? Some methods can track causes associated with FLW and others cannot.
  • Do you want to track progress over time? Some methods can assess increases or decreases in FLW across time to track progress.

Based on the answers to these questions, use Table 8 to determine which method or methods are most appropriate. If you are addressing multiple types of FLW (for example, both solid and liquid FLW), you may need to select several methods.

Table 8. How Some Methods to Measure Production Sector FLW Rank according to the Five Questions

Method Name Direct FLW Access Needed? Level of Accuracy? Level of Resources Required? Tracks Causes? Tracks Progress over Time?
Commonly used methods for gathering new data
Direct Measurement Yes High High Yes Yes
Interviews/Surveys No Low-Medium Medium-High Yes Yes
Commonly used methods based on existing data
Proxy Data No Low Low No No
Records No Variable* Low No Yes
Less commonly used methods at the production sector
Diaries No Low-Medium Medium Yes Yes
Mass Balance No Medium Low No 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 determing FLW levels, whereas other records are less accurate.
Note: The methods named are nonexhaustive.
Source: Authors.

For additional guidance in selecting a method, see the FLW Quantification Method Ranking Tool published by the Food Loss and Waste Protocol, which asks 11 questions about your circumstances and provides a ranked list of methods based on your answers.

Case Study for the Primary Production Sector

In the US state of California, the World Wildlife Fund (WWF) collected baseline primary data and supported measurement of post-harvest losses of several crops. The data were quantitative and qualitative data and they performed subsequent analyses to identify root causes of farm-level losses. They also calculated environmental impacts to illustrate the resource intensity of various crops and the associated impacts of any related FLW. Such a holistic measurement approach and conversion into other metrics helped identify the scale of FLW, identify root causes and find opportunities for interventions.

For example, during the 2017–18 growing season, the average measured losses at harvest on the farms sampled were 40 percent of fresh tomatoes, 39 percent of fresh peaches, 2 percent of processing potatoes and 56 percent of fresh romaine lettuce. Qualitative results highlighted the difficulties farmers face when balancing large yields and fixed contracts, as well as meeting strict product quality standards. WWF recommended further research into whole-farm purchasing contracts for specialty crops, flexible quality/visual standards and further valorization of preserved products to account for overproduction (WWF 2018).