Why and How to Measure Food Loss and Waste

Food Service/Institutions - Why and How to Measure Food Loss and Waste


The food service sector includes all institutions that serve prepared food intended for final consumption. In this sector, food products are taken from their raw, processed or manufactured state and prepared in-house. The final product is usually sold in single portions, though certain business models serve food in larger portions.

Examples of organizations in this sector are: restaurants, caterers, hotels or venues that prepare and/or serve food, street vendors, convenience stores with prepared food or cafeterias within facilities such as schools, hospitals and prisons.

In this sector, there is an important distinction between pre-consumer and post-consumer waste. Pre-consumer waste is any waste that occurs before the food is on the customer’s plate and post-consumer waste is any waste that occurs after that point. Some in the sector refer to this as “back-of-house” and “front-of-house,” respectively.

Some approaches to preventing FLW in food service are listed below.

  • Working with actors upstream in the food supply chain to increase the share of second-grade products that are accepted and valorized to some point.
  • Improving cold-chain management and infrastructure in order to prevent spoilage or degradation during storage and transport.
  • Reducing overproduction of under-consumed products or shifting from production models that routinely overproduce food (e.g., buffets).
  • Rethinking purchasing models in order to maintain freshness and reduce shrink.

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 your needs and the answers to these questions, you can use Table 12 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 multiple types of methods.

Table 12. Methods Used to Measure FLW in the Food Service Sector

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

*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.

Additional guidance can be found in the FLW Quantification Method Ranking Tool published by the Food Loss and Waste Protocol, which asks a series of 11 questions and provides a ranked list of methods based on your answers.

Case Study for the Food Service Sector

Sodexo has prevented FLW through its “WasteWatch powered by LeanPath” program, which reduces on site food waste by an average of 50 percent. This program uses smart scales, which categorize food waste and generate a food waste inventory that helps identify how much and where food goes to waste. These inventories and continuous direct measurement allow staff to identify hotspots, take action and monitor progress over time. Sodexo found that tailored messaging to employees improved staff engagement in the FLW prevention program and that this staff engagement was particularly impactful in the food service sector. Additionally, Sodexo identified products going to waste that could not be sold but were still safe for human consumption. In the United States, Sodexo has collaborated with Food Recovery Network, Feeding America and Campus Kitchens to connect surplus food to those in need (Clowes et al. 2018).