Rethinking food waste for a healthier planet
Authors: Peter Alexander, Dominic Moran
Journal: The Lancet Planetary Health (2017)

Losses throughout the food system increase demands on agriculture, with consequent environmental impacts. A less wasteful and more efficient food system is a desirable goal, but what constitutes a loss and the relative magnitude of different types of loss are less clear. Research and policy related to food waste typically imply that the food system boundary extends to the point at which food is eaten.1FAODo good—save food! Food and Agriculture Organization of the United Nations, Rome, Italy2017Google Scholar, 2Gustavsson J Cederberg C Sonesson U van Otterdijk R Meybeck A Global food losses and food wast textent, causes and prevention. Food and Agriculture Organization of the United Nations, Rome, Italy2011Google Scholar But if the objective of the food system is to provide sufficient healthy and nutritious food in a sustainable manner, then consumption in excess of nutritional requirements is also a form of food waste; the latter defined as the loss occurring from retailers' and consumers' behaviours.2Gustavsson J Cederberg C Sonesson U van Otterdijk R Meybeck A Global food losses and food wast textent, causes and prevention. Food and Agriculture Organization of the United Nations, Rome, Italy2011Google Scholar We suggest that the current food waste agenda and rhetoric warrants re-examination because overconsumption of food is more damaging to society than discarded food waste due to a combination of environmental and health costs. A last-portion dilemma can be posited, in which too much food is prepared for a meal and a proportion remains after the eaters are comfortably full. What are the issues that determine the socially responsible action, and what do they suggest about treating overconsumption as a loss? The desire to reduce waste seems to imply a duty for the diners to consume the remaining food. Other private and social behavioural motives might reinforce this action, such as a form of moral satisfaction from perceived waste reduction,3Kahneman D Knetsch JL Valuing public-good—the purchase of moral satisfaction.J Environ Econ Managet. 1992; 22: 57-70Crossref Scopus (1192) Google Scholar and discounting the long-term implications from being overweight.4Green L Myerson J A discounting framework for choice with delayed and probabilistic rewards.Psychol Bulln. 2004; 130: 769-792Crossref PubMed Scopus (1043) Google Scholar Such small individual acts across a large population would materially reduce discarded food, and if total demand remains constant, would be reflected in lower agricultural production. Consequently, less land, water, fertiliser, and agrichemicals would be used in agriculture, with benefits in terms of lower greenhouse gas emissions, as well as water and biodiversity conservation. But consider the alternative outcomes of so-called virtuous plate-clearing. If the additional portion does not displace other consumption—ie, the amount eaten subsequently is not reduced—then total consumption will have increased. A lack of displacement means no reduction in demand for agricultural commodities and no environmental benefits. If nutritional needs were already being met, increased bodyweight could result with associated health implications (eg, heart diseases and diabetes). Although additional food intake should be regulated by body homoeostasis; as a society we appear increasingly unable to control our weight, with an eighth of the global population being obese in 2014, treble the rate in 1975.5Di Cesare M Bentham J Stevens GA et al.Trends in adult body-mass index in 200 countries from 1975 to 2014: a pooled analysis of 1698 population-based measurement studies with 1·2 million participants.Lancet. 2016; 387: 1377-1396Summary Full Text Full Text PDF PubMed Scopus (3079) Google Scholar Sedentary lifestyles, processed foods,6Hu FB Globalization of diabetes: the role of diet, lifestyle, and genes.Diabetes Care. 2011; 34: 1249-1257Crossref PubMed Scopus (1253) Google Scholar and larger portion sizes are all implicated in this trend, imposing increasing costs on health services. For example, 13% (£16 billion) of the UK's health budget in 2014 was spent on medical costs associated with diabetes and conditions related to being overweight or obese.7Dobbs R Sawers C Thompson F et al.Overcoming obesity: an initial economic assessment. A discussion paper by the McKinsey Global Institute.http://www.mckinsey.com/industries/healthcaresystems-and-services/our-insights/how-the-world-could-better-fightobesityDate: November, 2014Google Scholar Consumption of the last portion has merely shifted losses from discarded food to excess consumption, and the total quantity of food produced and associated environmental pressures remain unaltered. Evaluation of food system losses until the food is eaten would misleadingly imply a reduction in waste. Overconsumption needs to be considered a loss for an accurate understanding to be presented. Although the individual circumstances of waste generation will be more varied than they are in this hypothetical dilemma, the associated issues and consequences remain. Aggregate global losses from overconsumption are at least as large as those from discarded waste at present. The annual social cost of greenhouse gas emissions associated with production of discarded and overconsumed food is around US$200 billion, assuming a high cost of carbon dioxide equivalent (CO2e) emissions of $80 per tonne applied to 20% of the 11 gigatonnes of CO2e per year total agricultural and land use emissions.8Alexander P Brown C Arneth A Finnigan J Moran D Rounsevell MDA Losses, inefficiencies and waste in the global food system.Agric Systs. 2017; 153: 190-200Crossref PubMed Scopus (235) Google Scholar, 9Smith P Bustamante M Ahammad H et al.Agriculture, Forestry and Other Land Use (AFOLU).in: Edenhofer OR Pichs-Madruga Y Sokona E Climate change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, USA2014: 811-922Google Scholar, 10Stiglitz JE Stern N Duan M et al.Report of the high-level commission on carbon prices.https://www.carbonpricingleadership.org/s/CarbonPricing_Final_May29.pdfDate: 2017Google Scholar A $2·0 trillion global obesity cost suggests that the health externalities are larger from overconsumption than from environmental impacts.7Dobbs R Sawers C Thompson F et al.Overcoming obesity: an initial economic assessment. A discussion paper by the McKinsey Global Institute.http://www.mckinsey.com/industries/healthcaresystems-and-services/our-insights/how-the-world-could-better-fightobesityDate: November, 2014Google Scholar Regardless, both health and environmental externalities are associated with substantial costs. Food discarded and overconsumed have equivalent environmental outcomes, but overconsumption also has negative health externalities, and therefore more damaging consequences overall. Because the losses due to overconsumption are as large as those from other food waste but create greater harm, the current policy focus1FAODo good—save food! Food and Agriculture Organization of the United Nations, Rome, Italy2017Google Scholar, 2Gustavsson J Cederberg C Sonesson U van Otterdijk R Meybeck A Global food losses and food wast textent, causes and prevention. Food and Agriculture Organization of the United Nations, Rome, Italy2011Google Scholar on discarded food seems disproportionate. Research and policy attention is needed to achieve the health–environment double dividend from reduction of overconsumption waste. Consumer behaviour can be economically rational but still lead to suboptimal system outcomes,4Green L Myerson J A discounting framework for choice with delayed and probabilistic rewards.Psychol Bulln. 2004; 130: 769-792Crossref PubMed Scopus (1043) Google Scholar including both forms of food waste. Influencing of these behaviours and the underlying preferences implies additional nudges for consumers—eg, to reduce portion size and to make greater use of leftovers, requiring policy and food industry engagement. Ultimately the synergies between health and environmental outcomes could be advantageous, as tackling the health burden might be a more politically and individually attractive entry point, with co-benefits for climate and environmental goals. We declare no competing interests.