Between a rock and a hard place: food waste or overeating

Global food waste is a pressing issue, causing economic losses and environmental damage. In 2018, 14% of globally produced food was lost before retail, and 17% was wasted during consumption. Nearly two-thirds of the latter occurred in households, making them household a key target for waste reduction efforts. Despite food waste being more prevalent in developed countries, the dual burden of economic and environmental impacts poses a greater challenge for developing countries. As a result, there is an increased focus on reducing food waste in these regions. However, an elusive but potentially persistent issue arises: given that household food must ultimately be either consumed or discarded, could reducing food waste lead to overeating when prepared quantities exceed family needs? Since discarding food is undesirable, compensating through overconsumption merely shifts the problem from waste management to health consequences, which is also not consumers’ want. My research explicitly generalizes the conventional definition of food waste beyond merely discarded edible food to encompass overeaten food as well. In this thesis, I first establish a conceptual framework that operationalizes an individual's decision-making process regarding overconsumption versus food disposal at satiety. Specifically, this framework adopts a bite-by-bite process where each incremental consumption decision involves a sequential evaluation - at each eating stage, the individual weighs the marginal utility of reducing waste (gain) against the disutility of exceeding optimal intake (loss). Within this framework, minimizing waste yields satisfaction, while heightened overeating induces discomfort. Individuals gauge the desirability of an additional bite when full by evaluating the overall benefit. The modeling results show that a stronger aversion to discarding or a diminished aversion to overeating increases the possibility of implementing overeating to avoid food waste. Additionally, this possibility is also contingent on the residual food volume at satiety - specifically, the total remaining quantity comprising both discardable surplus and potential compensatory consumption portions when reaching physiological satiety. This framework offers a feasible and concise approach to identifying whether an individual or a cohort is predisposed to implement overeating as a strategy to avoid food waste. Using data from the China Health and Nutrition Survey, my empirical analysis affirms that the level of generalized food waste indeed influences the likelihood of individuals resorting to overeating to avoid food waste. Furthermore, it elucidates that the trade-off between overeating and discarding differs across food nutritional content of the consumed food. Expanding on this theme and using the same dataset as the second chapter does, I relaxed a core assumption in the baseline model and introduces the interactions among household members, which allows the members to have different attitudes towards discarding food and overeating. The expanded conceptual framework produces a series of possible scenarios describing the pattern of mealtime dynamics between household members and corresponding features of each scenario that can be empirically examined. Using the same dataset as when I examine the baseline framework, the extended framework provides an explanation for the phenomenon that upon becoming parents, adults exhibit a higher likelihood of being overweight or obese: In contrast to childless adults, parents, driven by the dual objectives of avoiding household food waste and preventing their children from overeating, display an increased likelihood of engaging in overeating. My findings reveal a critical paradox in food waste mitigation: singular focus on minimizing plate waste through behavioral interventions creates a compensatory feedback loop where reduced food discards are offset by increased nutrition overconsumption. This necessitates reconceptualizing food waste as a multidimensional construct encompassing both physical discard and metabolic overburden. Crucially, this series of studies demonstrates that operationalizing this expanded definition through a dynamic decision-making framework—where residual food volume at physiological satiety serves as the pivotal decision node—provides new understandings for developing balanced interventions. The theoretical implications suggest a paradigm shift from viewing waste reduction and dietary moderation as competing priorities to understanding them as interconnected manifestations of the same resource allocation problem.