UC Berkeley

Recent headlines have called food waste “the world’s dumbest problem,” often pointing out that consumers are responsible for the majority of it in the United States. Edible food is discarded while there is continuing food insecurity and hunger. Discarding food is also associated with environmental, economic, and social costs. However, the characterization of this problem as dumb or simple fails to acknowledge that its causes are complex and inextricably linked to the structure of our food system, our relationships with food, and the demands of everyday life. My dissertation centers around why people discard edible food in households in the United States by focusing on various aspects of how they plan, shop, prepare, store, cook, eat, and discard food.

The aim of this dissertation is to augment the current dearth of information about causal mechanisms and determinants of consumer-level food waste and to interrogate how definitions of edibility influence household-level research. The central finding is that the behaviors associated with the production of wasted food in households are complex and diverse including a wide range of structural, social, cultural, technological, symbolic, and material factors. Understanding these factors and how they interact are key to identifying interventions that will effectively reduce the amount of wasted food.

Chapter one explores the concept of edibility as a sociocultural construct rather than a fixed feature of a food item. Increasingly, food waste measurement, research, and policy seek to differentiate between edible food and associated inedible parts, acknowledging different underlying causes for discard and different preferred solutions for managing the materials. Given the varying views of edibility within and across cultures, there is no single definition that is widely accepted. Specifically, this paper evaluates how different definitions of “edibility” influence outcomes of food waste measurement at the household level. Using kitchen diary data from households in Denver and New York City, four definitions of edibility were applied to food waste generation data. Based on the varying definitions, we found that the percentage of total food waste considered edible ranged from 52% to 71%. We also found that the top ten lists of most wasted edible food items changed based on the definition. The findings suggest that the definition of edibility does matter in terms of defining the extent of the problem, identifying hot spots for intervention, and tracking progress over time. We contend that edibility should be consistently and transparently defined, but also that how we define edibility should be considered in the context of policy and intervention goals.

In chapter two, we explore behaviors hypothesized to be linked to lower levels of edible food being discarded in households, such as meal planning and freezing foods. Using a Natural Resources Defense Council (NRDC) dataset from over 400 households in Denver and New York City, this chapter employs exploratory factor analysis and regression models to explore whether these behaviors are correlated with edible food waste generation. Weight-based food waste generation data from kitchen diaries were coupled with surveys that assessed frequency of participation in behaviors. After analyzing patterns of participation in twenty food waste-related behaviors, we identified three clusters representing “suites” of behavior: maximizing the consumption of already obtained food, meal and shopping planning, and minimizing overages from purchasing and cooking. The maximization factor was the only suite of behaviors found to have a statistically significant correlation with the generation of edible food waste, with greater participation in these behaviors associated with lower levels of wasted food. Although planning behaviors were not correlated, we contend that this does not mean that these behaviors are not important. Rather, we identify the potential intervening factors that could explain the lack of correlation. This chapter highlights the concept that participation in certain behaviors may have variable outcomes over time within and between households. Understanding these nuances with regard to how these behaviors are enacted within the priorities and contexts of everyday life is important to ensuring that suggested interventions are effective in reducing wasted food.

Finally, chapter three qualitatively explores how food becomes waste by focusing on the broader relationships households have with food. Open-ended interviews with 52 households in Oregon, Washington, and California were used to identify five key benefits associated with food that were linked to its non-consumption: pleasure/enjoyment, comfort, self-identity, convenience, and “good” food. I found that these benefits were sometimes realized through the consumption of food items that directly or indirectly resulted in the non-consumption of other food items (e.g. eating out instead of eating a planned meal to treat oneself during times of high stress); and were sometimes realized even if the food providing the benefit went unconsumed (e.g. stockpiling food items to feel more secure about access to food). Using theories of practice for the underlying theoretical foundation, I found that households participate in value negotiations, weighing costs and benefits, to maximize utility or satisfaction from food. These value negotiations include the intertwined household costs of money and time and lead to either the consumption or discard of food. Overall, this chapter illustrates why focusing solely on financial benefits of reducing wasted food may not be an effective lever for changing behavior.