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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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Suggested Citation:"1 Introduction." National Academies of Sciences, Engineering, and Medicine. 2020. A National Strategy to Reduce Food Waste at the Consumer Level. Washington, DC: The National Academies Press. doi: 10.17226/25876.
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1 Introduction F ood is both essential to life, providing vital nutrients and energy, and a source of pleasure and emotional sustenance. It has symbolic associa- tions with love, comfort, stress reduction, security, rewards, cultural expression, creativity, and power. Food choices are influenced by a lifetime of individual and social experiences. Food and eating behaviors are often set in childhood and can be closely tied to family and cultural traditions and norms. Despite its importance, however, people waste a significant amount of food, and the problem is growing. Hall and colleagues (2009) estimated that the amount of food wasted per capita in the United States had in- creased approximately 50 percent since 1974. Globally, one-third (1.3 bil- lion tons) of food produced for human consumption is lost or wasted each year (Gustavsson et al., 2011), at a cost of approximately $1 trillion (FAO, 2014). By one estimate, (based on measures of food waste in the municipal solid waste stream) across the U.S. food supply chain, from agriculture to consumption, approximately 40 to 60 million tons of food, both edible and inedible, is wasted (EPA, 2020; ReFED, 2016). An estimate based on measures of discarded food at all destinations is that once edible food leaves the farm, approximately 30 percent (66.5 million tons) is wasted each year (Buzby et al., 2014). 19

20 NATIONAL STRATEGY TO REDUCE FOOD WASTE PURPOSE OF THIS STUDY Many factors influence food waste in the United States, but because a significant portion of this waste occurs at the consumer level, interventions to alter consumer behavior will be vital if meaningful reductions are to be achieved. Yet despite broad agreement about the importance of reducing food waste throughout the supply chain (see, e.g., NASEM, 2019) and increasing attention to the problem, the majority of food waste reduction initiatives to date have not been focused at the consumer level. Reasons for this may include both a lack of evidence regarding effective strategies and insufficient attention to the complexity of causes and responses within a complex food supply system. In this context, the Walmart Foundation and Foundation for Food and Agriculture Research (FFAR)1 provided funding to the National Academies of Sciences, Engineering, and Medicine for a study of strategies for reducing food waste at the consumer level. To carry out this study, the Division of Behavioral and Social Sciences and Education and the Health and Medicine Division of the National Academies appointed a committee of experts to identify and recommend actionable strategies, including a path forward for implementation, for reducing food waste at the consumer level by apply- ing knowledge from the social and behavioral sciences, including lessons learned from the social sciences in other comparable arenas (e.g., water and energy conservation, recycling). The committee also considered issues of eq- uity and the potential for interventions to have different effects on different population groups. (Box 1-1 presents the committee’s statement of task.) The committee hopes that the strategies and recommendations detailed in this report will stimulate action and the coordination of effective strategies for reducing food waste at the consumer level, as well as further research to support future progress. SCOPE OF THE FOOD WASTE PROBLEM Characterizing the extent of the problem is challenging because there is substantial variation in how food waste is defined and measured, which makes comparisons and the tracking of progress difficult. Studies may dif- fer in, for example, the portion of food waste considered “edible” versus “inedible;” the part of the food supply accounted for (e.g., postharvest only versus the full food supply); and methodologies used for measuring wasted food (e.g., direct versus indirect methods) (Spang et al., 2019). 1 At the committee’s first meeting, the Walmart Foundation and FFAR made a presentation about the study charge and their perspectives on the need for the study. They had no other discussions with the committee throughout the study process.

INTRODUCTION 21 Box 1-1 Statement of Task An ad hoc committee will examine food waste in the United States at the individual consumer level at home and away from home. The committee will apply knowledge from the social and behavioral sciences to identify strategies for behavior change with consideration to interactions and feedbacks within the broader complex, dynamic food system. Drawing upon the food system overview described in A Framework for Assessing Effects of the Food System, the com- mittee will: • Review the existing data, information, and research on consumer food waste, including assessments of effectiveness for past and current reduction efforts; • Make actionable recommendations for food waste reduction strategies; and • Identify implementation strategies to reduce wasted food at the consumer level from a holistic, systems perspective. Furthermore, many estimates rely on secondary or outdated data (Xue et al., 2017), which increases the uncertainty of the estimates. Although recent efforts to develop standards and guidance have begun to address some of the problems with the quantification of food waste, many challenges remain (Hanson et al., 2016). (Appendix C provides a full description of the differ- ent methods used and various definitions of food waste and loss.) Nonethe- less, despite the complexities of the available information, it is possible to sketch out an overview of the problems and their consequences. First, as food moves through the food system from production to consumption, loss and waste occur at all stages, but the largest proportion occurs at consumption (Lipinski et al., 2013). It is not possible to be precise about the percentages because of the lack of alignment among the measures used, but several estimates demonstrate this point: • The portion of food waste occurring in U.S. households and places where consumers interact with food away from home has been estimated at close to 80 percent of the total (edible and inedible) amount of food waste produced (ReFED, 2016). • An estimated 30 percent (or 67 million tons) of edible food in the United States is wasted at the retail and consumer levels of the food system (Buzby et al., 2014; Gunders, 2017). • U.S. consumers waste approximately 1 pound of food per person daily, with fruits and vegetables most likely to be wasted, followed

22 NATIONAL STRATEGY TO REDUCE FOOD WASTE by dairy, meat, and grains2 (Conrad et al., 2018;3 Hoover and Moreno, 2017; McDermott et al., 2018). Looking at just the household level, some researchers have collected empirical data to estimate the portion of all wasted food that is edible by food type and discard destination (Hoover and Moreno, 2017; McDermott et al., 2019). Small studies have also quantified plate waste (the portion of food that is served but ultimately wasted) (e.g., Roe et al., 2018). Still, empirical food waste data come primarily from sources that have not been peer reviewed or were published outside of the United States, such as the Wasted Resources Action Programme (WRAP) in the United Kingdom (­ illick and Quested, 2018; Quested and Luzecka, 2014; Quested et al., G 2013). Even less information is available about the proportion of consumer- level food waste that occurs in the home versus out-of-home settings, which would be useful for prioritizing resources. Although it is clear that consumers waste a substantial proportion of the food they buy, food disposal is only one consideration when they make decisions about food. For example, a 2019 survey of U.S. consumers found that fewer than half think about food waste some of the time when they are at the grocery store, eating out, or at home (IFIC, 2019). The survey also revealed that such factors as price and preferences are more important than food waste considerations in making decisions about food. The consequences of food waste are severe: the wasting of food de- pletes natural resources, degrades the environment, and constrains efforts to increase access to healthy diets for low-income populations. Life-cycle analyses have been used to quantify and disaggregate the environmental im- pacts of food production (Heller and Keoleian, 2015; Ivanova et al., 2016; Nemecek et al., 2016). One estimate is that the impacts of production and use of food from production to consumption are responsible for 48 percent and 70 percent of global household impacts on land and water resources, respectively (Ivanova et al., 2016). When food goes uneaten, the environmental impacts stem from both waste of the resources used to grow the uneaten food and its disposal. By one recent estimate, food waste accounts for 15 percent of the total municipal solid waste generated in the United States (EPA, 2019), a figure that does not include all discarded food, such as that disposed of down the drain. The food waste in landfills is converted partly to methane, a 2 The greatest economic cost is for uneaten meat, poultry, and fish, followed by vegetables and dairy products (Buzby et al., 2014). 3 Estimate based on secondary data from the U.S. Department of Agriculture’s (USDA’s) Loss-Adjusted Food Availability data series.

INTRODUCTION 23 greenhouse gas4 with 28 times the warming potential of carbon dioxide. Thus, it is estimated that the average American contributes 315 pounds of carbon dioxide equivalent annually (28 percent of all landfill greenhouse gas emissions) by discarding edible food and food packaging (Kling and Hough, 2010). Greenhouse gases are also emitted in the process of grow- ing, processing, distributing, transporting, retailing, and cooking food that is eventually wasted. With all that in mind, a typical American’s annual food waste could account for the emission of more than 12,000 pounds of carbon dioxide equivalent, which is approximately the level of emissions from driving a car for 13,500 miles (Kling and Hough, 2010). Globally, the emission of 4.4 gigatons of carbon dioxide equivalent—8 percent of annual global greenhouse gas emissions—results from food that is wasted (FAO, 2015). In terms of global land use, a total of 1.4 billion hectares, an area nearly 1.5 times that of the United States, is used to grow food that is ulti- mately wasted (FAO, 2019). This is significant because land use ultimately has effects on biodiversity and people’s livelihoods. Moreover, the applica- tion of nutrients used in growing food that is eventually discarded results in increased ammonia emissions, which further degrade air and soil quality, as well as wasted water and runoff-induced algal blooms in coastal waters. The amount of food produced but uneaten also implies substantial waste of water and energy, essential natural resources. For example, wasted food is responsible for more than 25 percent of total agricultural use of fresh water and about 4 percent of total U.S. oil consumption (Hall et al., 2009). Researchers have used modeling to estimate that halving food waste across all stages of the food supply chain could reduce the total environmental impact of the U.S. food system by 8 to 10 percent (Read et al., 2020). Even as more than 30 percent of total food produced in the United States is wasted, 42 million Americans struggle with food insecurity (Coleman- Jensen et al., 2016). This disconnect is even more striking at the interna- tional level. According to the Food and Agriculture Organization (FAO), 1.3 billion tons of food is wasted globally, while nearly 900 million people are undernourished (FAO, 2019). As distressing as these figures are, it is important to note that much of the food that is wasted cannot realisti- cally be recovered for human consumption, for reasons including food quality and decay, logistics, and the costs of recovery. Most food that gets wasted in the home is not likely to be appropriate for donation. Efforts to reduce consumer food waste have important benefits, but a broader suite 4 Estimation of greenhouse gas emissions in terms of “carbon dioxide equivalent” facilitates comparison of estimates of different greenhouse gases, for example, carbon dioxide, methane, and nitrous oxide.

24 NATIONAL STRATEGY TO REDUCE FOOD WASTE of interventions is needed to make that food available and affordable to households experiencing food insecurity. APPROACH TO THE STUDY As this overview of the scope of the problem suggests, the study com- mittee’s charge required careful thinking about research and conceptual approaches from multiple fields. Accordingly, the committee included ex- perts in food waste, psychology and marketing, sociology, public health, nutrition, behavioral economics, food systems, urban planning, interven- tion design, and implementation science (see Appendix F for biographical sketches of the committee members). Study Process The committee’s conclusions and recommendations are based primarily on a review of the relevant technical literature and two public sessions held with researchers and leaders in the field of food waste and other relevant fields (see Appendix A for the agendas for these public sessions). The committee reviewed the existing body of research on food waste at the consumer level, including assessments of the levels of waste and as- sociated impacts, current and past interventions to reduce this waste, and drivers of consumer behavior around wasted food. To review this literature, the committee developed a search strategy that was applied to multiple da- tabases (Agricola, Embase, Medline, ProQuest Research Library, PubMed, and Scopus). The search included peer-reviewed articles published in Eng- lish after 2004 (see Appendix B for the search syntax and results). A total of 882 publications were scanned for relevance to the committee’s task. In addition to the peer-reviewed literature, the committee reviewed grey lit- erature on efforts of various groups to reduce food waste at the consumer level, including interventions, guidelines, and various other relevant topics. The committee also sought insights in domains identified as similar to that of food waste for the purpose of studying consumer behavior and ways to influence it. Thus, the committee conducted additional literature searches targeting systematic reviews of research on strategies for promoting energy conservation, water conservation, waste prevention/management, recycling, diet change, and weight management. Finally, the committee notes that the U.S. food supply chain and econ- omy have experienced substantial disruptions during the COVID-19 global pandemic, which started in 2019 when the committee had completed most of its deliberations. There is not yet evidence regarding how consumer food waste patterns may have shifted during the pandemic, but the disruptions have undoubtedly affected consumers and their behaviors and had other

INTRODUCTION 25 impacts on the food supply around the world.5 Increases in food insecurity and challenges for consumers in efficiently acquiring food are just two of the issues that have already become obvious. It is possible that the chal- lenges of the pandemic could increase consumers’ receptivity to efforts to assist them in reducing waste. This report could not address these fast- moving changes, but uncertainties about how the food supply and future consumers’ behaviors will be shaped by the pandemic underscore the im- portance of attention to food waste. A Systems Approach The committee was asked to consider the full breadth of the complex, dynamic food system and in its analysis to draw on the food system over- view presented in A Framework for Assessing Effects of the Food System (IOM and NRC, 2015) (see Box 1-1). A recommendation of that report is to move beyond a linear food supply chain model (from farm to table to landfill) to one that accounts for the interconnectivity and dynamic relationships among the various systems and structures within the food system (see Figure 1-1). Taking a systems approach makes it easier to understand and minimize the unintended negative consequences of inter- ventions (tradeoffs), as well as to identify opportunities to maximize the benefits of changes, by illuminating the interactive relationships within the food system. The 2015 report provides a framework intended to be applicable to many situations and to support the anlysis of proposed interventions aimed at influencing aspects of the food system. With this in mind, the committee attempted to apply the four principles laid out in the 2015 report to the food waste context while also recognizing the practical issues that must be addressed, such as uncertainties and gaps in data and information. Principle 1: Recognize effects across the full food system. Consumer be- havior, the focus of the current report, is shaped—or driven—by upstream influences. That is, the actions of farmers or food processors, for example, shape the context in which consumers make conscious and unconscious de- cisions and the options they have. Thus the committee investigated not only drivers of consumer behavior (see the discussion of terminology below) and interventions that directly affect individuals, but also other factors, such as policy, the actions of the food industry (i.e., food service venues and food retailers) and the media, and food marketing. We bounded our search by focusing on drivers that are proximal to the consumer and on interventions designed to prevent or reduce food surplus. 5 See, e.g., http://www.ipes-food.org/_img/upload/files/COVID-19_CommuniqueEN.pdf; https://wrap.org.uk/sites/files/wrap/Citizen_responses_to_the_Covid-19_lockdown_0.pdf.

26 NATIONAL STRATEGY TO REDUCE FOOD WASTE FIGURE 1-1  The U.S. food supply chain is a multilayered system that is interconnected with the larger biophysical environment and the social context. SOURCE: IOM and NRC, 2015 (Figure S-2). Principle 2. Consider all domains and dimensions of effects. The 2015 report notes that any intervention targeting the food domain may have consequences not only in that domain but also in other domains, such as health. The consequences in other domains may be positive or negative, intended or unintended, and they can be disproportionally larger than those intended for the intervention. The committee found limited research salient for exploring this issue with respect to food waste, but wherever possible, we considered potential consequences of interventions to reduce food waste in other areas, such as the possible effects of a technology used for this purpose on food safety. Principle 3. Account for system dynamics and complexities. The food system is dynamic and heterogeneous, characterized by substantial variabil- ity in the goals and motivations of stakeholders and in the influences that drive consumer behavior. The committee acknowledged these variables and the tensions among them even when relevant empirical data or resources for obtaining such data were not available. Principle 4. Choose appropriate methods of analysis and synthesis. Study of the topic of food waste is hampered by factors that include limited experience in this area among researchers, industry, and communities, as well as the lack of standard research methodology and terminology noted earlier. Accordingly, this report includes the committee’s recommendations for improved methods, including analytical and modeling approaches, that would provide a more complete picture of the drivers of food waste behav- iors and inform the selection of interventions.

INTRODUCTION 27 Although existing research did not support a true systems analysis of the problem of food waste, the committee applied the ideas behind such an analysis by taking into account • the influence of other factors and actors in the food system beyond the consumer; and • the synergy among various drivers of food waste. We also explored the work of other authors in the field of systems thinking, such as Meadows (1999, 2008), who proposes a framework for systems change in which different types of interventions work in synergy to address a particular societal challenge. Others have categorized the types of prevention interventions to reduce food waste at the consumer level as “strong” or “weak” (Mourad, 2016): a strong intervention is one with long-term benefits that calls for changing the roots of the problem, whereas a weak intervention focuses on consumer behavior alone. The committee considered these concepts in its deliberations. Integrating Work from the Social, Behavioral, and Economic Sciences Researchers in fields including food science, nutrition, public health, behavioral economics, marketing, sociology, social psychology, land use planning, geography, and implementation science have in one way or an- other contributed to understanding of why consumers do what they do and how consumer behaviors can be shaped through interventions. While each of these fields has made important contributions, they identify and investi- gate questions in different ways that reflect the conceptual underpinnings of their disciplines. For example, some psychologists and behavioral economists consider food waste primarily as a context within which fundamental psychological effects may be explored or knowledge extended. Specialists in food market- ing tend to look to data from either laboratory or field experiments that systematically alter one aspect of the food decision environment, with the goal of isolating novel effects on, say, quantities purchased or willingness to pay, rather than focusing on reducing waste as a key outcome. Behavioral economists use field studies to test how well findings from psychology and economics work in real-world settings. Scholars in urban geography and planning explore the role of space and the built environment in shaping food practices and the influence of such factors as urbanization, class, cul- ture, and infrastructure. Public health nutrition researchers analyze food- and nutrition-related behaviors, perform program and policy evaluations, and study individual, social, and structural factors that shape behaviors and

28 NATIONAL STRATEGY TO REDUCE FOOD WASTE opportunities. Agricultural and resource economists may draw on broad- scale survey data as well as laboratory and field experiments, often consid- ering human-ecosystem feedback, the effects of informational interventions, and the interactions between business and individual behaviors as related in particular to the food system. And researchers in implementation science, a field that has blossomed in the last decade, focus on the specific elements needed to use the findings from small-scale studies successfully in designing population-scale interventions that can change behaviors. Researchers in several of these fields complement quantitative approaches with qualitative studies to better understand the underlying dynamics and processes that shape behaviors and their contexts. Diverse Terminology Coordinating findings from across such disparate areas of study poses a challenge. Researchers in these fields are seeking to understand similar phenomena from their own perspectives and have developed terminology that is idiosyncratic to their domains. Their distinct usages of often similar terms reflect conceptual differences in their approaches. The discrepancies in usage can confuse interpretation and meaning. A key concept in the study of food waste illustrates the problem: the influences on behavior that are called “drivers” in many contexts are also referred to as “determinants,” “determining factors,” “motivators,” or “predictors” in other fields, with definitions that overlap significantly but are not identical. These terms reflect varying stances on what is most impor- tant (e.g., the statistical meaning of prediction versus behavioral influences such as motivation), which can make it challenging to parse the meaning of similarities and differences in findings. At the same time, the diffusion of new categorizations and terminology can allow meaningful comparisons to emerge across fields. The definition of food waste itself is another challenge. As noted earlier, researchers who study food waste define it in varying ways (e.g., sometimes including spoiled or otherwise inedible food and sometimes not), and also measure it in multiple ways, which complicates the comparison and integra- tion of data and analysis. For the purposes of this report, “food waste” is defined as food that is either still edible or became spoiled before it could be consumed and is discarded by consumers in any discard location, includ- ing landfills or composting facilities. While recognizing that whether a food (or part of a food) is considered edible depends on cultural, religious, and even personal preferences, the committee focuses only on edible food in this report, given that it is the portion most conducive to waste prevention. Further, this report focuses on consumer-level waste; waste at other levels of

INTRODUCTION 29 the food supply chain (e.g., at the retail level) is relevant to this report only to the extent that it influences waste at the consumer level. For example, the food wasted by the consumer in food service venues (e.g., restaurants, school cafeterias) is within the scope of this report. Conversely, the waste that occurs in the operation of food service venues as food is purchased and prepared, although equally important, is beyond the scope here, as is the food waste resulting from retail store operations. Other terms relevant to this report are defined as they arise in the discussion. Appendix G provides definitions of all terms with the potential to cause confusion. Theoretical Frameworks The use of theories of change and conceptual frameworks helps iden- tify bridges and address inconsistencies in the study of consumer behavior. Theories and frameworks can guide the design of behavioral interventions by identifying constructs and mechanisms that are important to the de- sired outcomes, which in turn supports the identification of variables and outcomes that will need to be measured in order to disaggregate effects (Thomson and Ravia, 2011). However, relatively few studies of interven- tions designed to influence behavior use theoretical frameworks to guide design (Sweet and Fortier, 2010; Thomson and Ravia, 2011; Varotto and Spagnolli, 2017). In some domains, such as diet- and physical activity- related behavior change, researchers have found only sparse and inconsis- tent evidence that theory-based interventions are effective or lead to better outcomes (Samdal et al., 2017). In addition, behavioral theories can be poor at explaining how the initiation and maintenance of behavior might differ (Samdal et al., 2017). Despite these challenges, researchers can beneficially apply theories and frameworks to standardize monitoring and evaluation practices and reporting of outcomes (Cox et al., 2010; Fjeldsoe et al., 2011). Some of this work has been the basis for the development of models designed to account more holistically for consumer behavior. The committee’s review of the six behavioral domains identified as similar to that of food waste demonstrated that multiple theories have been dominant in studies of behavioral change, ranging from the psychological (the theory of planned behavior and modified versions [Ajzen, 1991]) and value-norm-belief theory (Stern and colleagues, 1999, 2000) to others based in sociology (e.g., versions of social practice theories [Schanes et al., 2018]). While each has some strengths, they all have shortcomings that make them difficult to apply across a broad literature; Box 1-2 provides a look at the context in which these theories emerged. The committee considered the ap- plicability of several theoretical frameworks to consumer-level food waste behavior.

30 NATIONAL STRATEGY TO REDUCE FOOD WASTE Box 1-2 The Science of Behavior Change Many theories and frameworks have been used to understand and predict individual behavior. There is no consensus on which theories and frameworks are most useful, and the dominant theories have evolved over time. Early theo- ries of behavior change, such as social cognitive theory, the theory of planned behavior, and the transtheoretical model, were influential efforts to explain why people adopt a behavior. This set of theories characterized human behavior as being predominantly conscious and reason driven, and this category of behavior is sometimes referred to as “System 2” processing (Koop et al., 2019; Marteau, 2017; Varotto and Spagnolli, 2017). Theories focused on System 2 behavior high- light the role of knowledge transfer and ways to improve self-efficacy in changing behavior (Koop et al., 2019). The shortcomings of System 2 theories for explaining behavioral outcomes was increasingly apparent by the end of the 20th century, as the importance of accounting for automatic and emotion-driven factors was recognized (Marteau, 2017). New models of behavior (sometimes called System 1 theories) emerged that characterized human behavior as being more automatic and emotion driven than the System 2 theories had allowed. Most recently, it has been recognized that individual behaviors are responsive to both System 1 and 2 processes, and researchers have begun to measure drivers and create study designs that take both into account. The theory of planned behavior focuses on drivers related to the intention to behave in a certain way. Researchers that use the theory of planned behavior, therefore, often do not focus on measuring actual behavior (Graham-Rowe et al., 2014; Koop et al., 2019; Stancu et al., 2016; Stefan et al., 2013; Visschers et al., 2016; van der Werf et al., 2019). Though heavily used in the food waste litera- ture, this theory has shortcomings for explaining food waste behavior (Schanes et al., 2018). First, the theory is best suited to capturing consumers’ intentions to engage in single behaviors, divorced from other considerations that may cre- ate disconnects between their intentions and their actions. Indeed, the amount of food consumers waste is often determined not only by their intentions, but also by contextual factors they cannot control that impede their intended actions. Further, food waste is often driven by factors outside the scope of conscious choices, many of which occur in tandem with contextual and social factors that are not intended or planned by the consumer (Quested et al., 2013). Scholars have labeled this phenomenon the “value-action gap” (Barr, 2006). Because there may be a substantial gap between intentions and behavior related to waste, a theory that focuses so heavily on intentions may offer little explanation of actual behavior. The value-belief-norm theory, offered by Stern and colleagues (1999, 2000), was developed primarily for application in the field of nonactivist environmental behaviors. This theory posits that biospheric,a altruistic, and egoistic values give rise to beliefs that shape behaviors. These values influence individuals’ general ecological worldview, understanding of adverse consequences of behaviors that harm the environment, and sense of their own ability to reduce such harms.

INTRODUCTION 31 Together, these beliefs may then give rise to proenvironmental personal norms, which drive a host of behaviors. This framework has shown strong predictive power in the domain of environmental behaviors, which suggests potential value in the food waste context if food waste were seen by consumers primarily as an environmentally damaging action. However, even if environmental beliefs and norms are drivers for some consumers in some cases, this approach addresses only the individual decision maker, not the many other elements of the food waste system. Widely used in qualitative research, theories of practice (also known as social practice theory or practice theory) are used to understand routinized be- haviors. In contrast to the theory of planned behavior, theories of practice treat consumer action as being influenced by a rich combination of factors. According to Shove and colleagues (2012), the three key elements of practice theory are (1) material (e.g., technologies, infrastructure, tools, logistics, objects); (2) meaning (e.g., values, cultures, emotions, paradigms); and (3) competence (skills, capac- ity, and knowledge). Social practice theory recognizes that individuals’ practices and behaviors are shaped by a combination of the three interrelated factors (Har- greaves, 2011; Reckwitz, 2002; Shove et al., 2012; Warde, 2005). In this model, practices and behaviors are not regarded simply as individual choices: the influ- ences of institutions and systems are taken into account (Mattioni et al., 2020). Behavior is thus likened to practices, defined as repeated actions that are enacted together. According to these theories, discarding food should be considered a “bundle of practices,” including behaviors related to the planning, provisioning, preparation, consumption, and discarding of food. Understanding each of these behaviors by itself and in relation to the others is critical to understanding how food is transformed into waste by households (Hargreaves, 2011; Southerton and Yates, 2015). Because they take into account how consumer behavior is influenced by social and marketing cues, theories of practice provide a natural link to a systems perspective. However, the majority of work applying these theories does not allow for broad quantification of the effects of interventions or for comparisons across studies.b Further, while the concept of bundles of practices offers important in- sights, this combinatory approach makes it more difficult to identify separate driv- ers that may appear across contexts. Thus, results from studies applying these theories are difficult to generalize or integrate with those that identify single drivers of food waste (see Soma, 2019). aA biospheric value orientation is the perspective that concern for the health of the bio- sphere, earth’s biological system, should guide moral and ethical decisions. bFor example, Soma (2019) quantitatively applied theories of practice to understand the influence of income and retail choice on food waste in households in Indonesia.

32 NATIONAL STRATEGY TO REDUCE FOOD WASTE A framework that allows the identification and analysis of individ- ual behavioral drivers but also acknowledges the importance of context and habit in driving behavior—the motivation-opportunity-ability (MOA) framework—has been used in food waste research in both academic and practitioner settings (e.g., Scott et al., 2015; van Geffen et al., 2016) and related fields (e.g., Addo et al., 2018; Geiger et al., 2019; MacInnis and Jaworski, 1989). The committee found that this model offered the most useful approach for analyzing the drivers of food waste behaviors and interventions to modify those behaviors in the context of our statement of task (Box 1-1). The key elements of this framework as they apply to food waste have been defined as follows (van Geffen et al., 2016): • Motivation to prevent food waste—a person’s willingness to per- form actions that reduce the likelihood or amount of food waste being generated. Relevant aspects of motivation are attitude, awareness, and social norms. • Opportunity to prevent food waste—the availability and acces- sibility of materials and resources required to prevent food waste. Relevant aspects of opportunity are time and schedule, economic and other contextual factors, material and technologies, policy, and infrastructure. • Ability to prevent food waste—a person’s proficiency at solving the problems encountered when performing actions that help prevent food waste. Relevant aspects of ability are knowledge and skills. Like theories of practice, the MOA framework supports analysis of behavior that may be driven by habit rather than explicit intention. Indeed, the MOA framework also makes clear that when motivation, opportunity, or ability is low, consumers are likely to be influenced by factors related to routine, choice context, nonconscious factors, or social norms, and that addressing individual, group, and societal cues will increase the chance of sustained behavioral change. This insight is important in a systems ap- proach to reducing food waste. A few examples illustrate the interactions among motivation, oppor- tunity, and ability. Even for individuals who wish to reduce food waste (have high motivation), refrigerators that are set at the wrong temperature (low opportunity) may make it very difficult to translate that motivation into the desired outcome. On the other hand, ignoring motivation can also undermine efforts in two ways. First, communities may provide ample op- portunity and ability to reduce food waste, but if individuals are faced with conflicting motivations (i.e., conflicting drivers), such as the desire to take advantage of bulk buying opportunities, those interventions are not likely to succeed. Second, if executing behaviors to reduce food waste requires

INTRODUCTION 33 high levels of motivation, the level of motivation in itself may be a driver of food waste. Where motivation is relatively low, opportunity and ability may need to be so strong that wasting food would require more effort than not doing so. One way to address this would be to build habit systems that make nonwasting automatic. For example, a community might develop a program whereby opting in to food waste reduction processes is automatic, but opting out would require more effort. In this case, consumers would need little motivation—they would simply need to lack a countervailing motivation. The MOA framework allows for consideration of the roles of habits, norms, and other automatic behaviors. The committee used the MOA ap- proach to anchor its analysis of the possible drivers of consumer behaviors and interventions designed to change those behaviors. STRUCTURE OF THE REPORT The remainder of this report is organized into five chapters. Chapter 2 describes the context for food waste at the consumer level. Chapter 3 discusses the drivers of consumer-level food waste, including both lessons learned from other disciplines and the research specific to food waste. It identifies implications for the design of interventions targeting food waste behaviors. Chapter 4 reviews the research on interventions to reduce food waste, again taking into account lessons from other disciplines. Chapter 5 presents the committee’s strategy for reducing food waste and its recom- mendations for implementing this strategy. Finally, Chapter 6 describes research needed to support the design of interventions and highlights the importance of implementation planning. REFERENCES Addo, I.B., M.C. Thoms, and M. Parsons. 2018. Household water use and conservation be- havior: A meta-analysis. Water Resources Research 54(10):8381-8400. Ajzen, I. 1991. The theory of planned behavior. Organizational Behavior and Human Decision Processes 50(2):179-211. Barr, S. 2006. Environmental action in the home: Investigating the ‘value-action’ gap. Geog- raphy 91(1):43-54. Buzby, J.C., H.F. Wells, and J. Hyman. 2014. The estimated amount, value, and calories of postharvest food losses at the retail and consumer levels in the United States. Economic Research Information Bulletin 121. Coleman-Jensen, A., M.P. Rabbitt, C.A. Gregory, and A. Singh. 2016. Household food security in the United States in 2015, ERR-215. Washington, DC: U.S. Department of Agricul- ture, Economic Research Service. Conrad, Z., M.T. Niles, D.A. Neher, E.D. Roy, N.E. Tichenor, and L. Jahns. 2018. Relation- ship between food waste, diet quality, and environmental sustainability. PLoS ONE 13(4):e0195405.

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Approximately 30 percent of the edible food produced in the United States is wasted and a significant portion of this waste occurs at the consumer level. Despite food's essential role as a source of nutrients and energy and its emotional and cultural importance, U.S. consumers waste an estimated average of 1 pound of food per person per day at home and in places where they buy and consume food away from home. Many factors contribute to this waste—consumers behaviors are shaped not only by individual and interpersonal factors but also by influences within the food system, such as policies, food marketing and the media. Some food waste is unavoidable, and there is substantial variation in how food waste and its impacts are defined and measured. But there is no doubt that the consequences of food waste are severe: the wasting of food is costly to consumers, depletes natural resources, and degrades the environment. In addition, at a time when the COVID-19 pandemic has severely strained the U.S. economy and sharply increased food insecurity, it is predicted that food waste will worsen in the short term because of both supply chain disruptions and the closures of food businesses that affect the way people eat and the types of food they can afford.

A National Strategy to Reduce Food Waste at the Consumer Level identifies strategies for changing consumer behavior, considering interactions and feedbacks within the food system. It explores the reasons food is wasted in the United States, including the characteristics of the complex systems through which food is produced, marketed, and sold, as well as the many other interconnected influences on consumers' conscious and unconscious choices about purchasing, preparing, consuming, storing, and discarding food. This report presents a strategy for addressing the challenge of reducing food waste at the consumer level from a holistic, systems perspective.

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