Blog Post

Measuring Food Loss and Waste

The global food system puts significant pressure on the world’s natural resources and is a major contributor of greenhouse gas emissions. At the same time, a large amount of the food produced by this system is either lost or wasted each year, lowering overall productivity and hurting both producers and consumers. According to a recent blog by IFPRI Director General Shenggen Fan, as much as one billion tons of food never reaches consumers. Thus, food loss and waste pose a significant challenge for both food security and sustainability, important goals of the Sustainable Development Goals (SDGs). SDG target 12.3, in fact, calls for halving global food waste at the retail and consumer levels and reducing food losses along the food value chain by 2030.

As Chapter 3 of IFPRI’s 2016 Global Food Policy Report points out, however, meeting this goal will first require food loss and waste data to be significantly improved. The first challenge lies in actually defining “food loss and waste.” Loss and waste occur at different points along the food value chain, from production to processing to retail and final consumption. As the authors discuss, much disagreement remains regarding proper terminology to capture this broad concept. “Food loss”, “postharvest loss”, “food waste”, and “food loss and waste” do not refer to the same aspects of the problem, but these phrases are generally used interchangeably, muddying the waters in terms of what types of loss are actually being examined.

The chapter also highlights the fact that these commonly-used definitions often do not include important pre-harvest losses, such as crops lost to pests before harvest, crops left in the field due to sudden price decreases that negate the effort of harvesting, crops that failed to produce food due to limited use of agricultural inputs or technology.

These varying, and limited, definitions impact how food loss and waste is measured. The macro approach aggregates data from national and local authorities and large companies; it is cost-effective and measures overall loss and waste along the value chain, but it does not provide representative, high quality data for low- and middle-income countries or for certain stages of the value chain, such as primary production, processing, and retail. The micro approach focuses on specific value chain actors at different value chain stages. This provides more region- and context-specific data and is more useful than the macro approach for determining potential loss prevention strategies, but it is costly and time-consuming. In addition, micro results are difficult to compare across different value chains and regions because studies often use different data collection and estimation strategies to meet their specific objectives and each value chain environment faces a number of particular constraints

These differences in definition and measurement have resulted in widely-varying estimates of how big a problem food loss and waste actually is. According to the chapter, recent estimates of the magnitude of global food loss and waste have ranged from 27 percent to 32 percent of all food produced worldwide. These wide ranges continue at the commodity level as well; according to the FAO, cereal losses are estimated at anywhere from 19 percent to 32 percent, while fruits and vegetable losses range from 37 percent to 55 percent.

To address these shortfalls in measurement, the chapter proposes the use of a new definition: potential food loss and waste (PFLW). This new terminology, the authors argue, will incorporate loss and waste along all stages of the value chain, from pre-harvest to table waste, thus capturing losses and unrealized potential production that many other definitions leave out.

In addition, assessments should look at specific stages along the value chain where loss and waste occur, rather than focusing on overall loss and waste. This will require the recognition that loss and waste differ in developed and developing countries and that the methodologies used to estimate loss and waste in these countries will need to differ as well.

In low- and middle-income countries, data regarding food loss and waste is often limited. To help ease the restrictions due to data availability, the methodology used should be applicable across multiple crops and regions. Surveys should focus on farmers, middlemen, wholesale buyers, and processors to allow for characterization of inputs, harvesting techniques, storage, handling, and processing practices, as these are the factors that lead to the most loss in developing countries. The chapter suggests using the highest potential production level for the particular commodity and region under study, expressed in either quantities or equivalent prices; using this potential production number guarantees the inclusion of pre-harvest losses and losses relative to potential yields. Furthermore, using quantity or price explicitly helps differentiate between a loss in physical quantity and a reduction in quality or value.

In developed countries, on the other hand, detailed data on food loss and waste at the processing, distribution, wholesale, and retail stages of the value chain does exist, but companies often do not make this data available to researchers or policymakers. Thus, there is a strong need for more transparency. The methodology used in these countries should capture both losses in food quantity and losses in food quality, as well as discretionary food waste in the processing, distribution, and retail stages and food waste at the consumer level, such as food discarded in stores and restaurants and in households.

In addition to improving how food loss and waste is measured, policymakers need to set concrete goals that meet the specific conditions of their country. For developed countries, goals should focus on reducing food waste; for developing countries, policymakers should focus on reducing food loss along earlier stages of the value chain (pre-consumer stages) but they should also learn from the best practices in terms of reducing food waste in the future as their economies progress and their populations’ consumption patterns change.

To properly set these goals, the authors say, research should examine the causes of food loss and waste at both the micro and the macro level. At the micro level, there is evidence that credit constraints in developing countries often prevent value chain actors, particularly smallholder farmers, from adopting technologies to increase food production or reduce loss and waste. Other micro-level causes include a lack of access to information about technologies and practices to prevent food loss, such as proper storage techniques to keep out pests and damaging moisture, and poor rural infrastructure that makes it difficult and costly for farmers to get their produce to market.

At the macro level, overly strict food safety and quality regulations can prevent food that is in fact safe from being accepted for import or into markets. Providing information on food safety and changing consumer preferences and demands as populations’ incomes grow can also impact whether, and what types of, food is wasted at later stages of the value chain.

Interventions to address these causes will only be successful if they are cost-effective and tailored to specific country, commodity, or value chain needs. Platforms for information exchange, such as the Technical Platform on Food Loss and Waste launched by IFPRI and FAO, form an important first step in ensuring that policymakers and researchers have access to the highest quality data and best practices for reducing food loss and waste.

Read more about food loss and waste in Africa south of the Sahara, India, and Central America and the Caribbean.