Food loss and waste is food that is discarded or otherwise lost uneaten. This occurs throughout all the processes involved in the food system, during production, processing, distribution, retail, and consumption, but most food waste is created after consumers buy the food. Overall, about one-third of the world's food is thrown away, and a huge amount of resources used in food production are wasted. Global food waste amounts to 931 million tonnes annually (about 121 kg per person) across three sectors: 61 percent from households, 26 percent from food service and 13 percent from retail.

Food waste is addressed through prevention (e.g. by food preservation), reuse (e.g. food donation), animal feed, or recycling. Discarding food in landfills is to be avoided because it is a major source of the greenhouse gas methane. Reducing food waste in all parts of the food system is an important part of reducing the environmental impact of agriculture, by reducing the total amount of water, land, and other resources used.

Wasted food is a major part of the impact of agriculture on climate change (it amounts to 3.3 billion tons of carbon dioxide equivalent emissions annually) and other environmental issues, such as land use, water use and loss of biodiversity. It also conflicts with food insecurity in parts of the world. The UN's Sustainable Development Goals seek to "halve global per capita food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses" by 2030.United Nations (2017) Resolution adopted by the General Assembly on 6 July 2017, Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development (A/RES/71/313 ) In the 2022 United Nations Biodiversity Conference nations agreed to reduce food waste by 50% by the year 2030.

Definition

Food loss and waste occurs at all stages of the food system – production, processing, sales, and consumption. Definitions of what constitutes food loss versus food waste or what parts of foods (i.e., inedible parts) exit the food supply chain are considered lost or wasted vary. Terms are often defined on a situational basis (as is the case more generally with definitions of waste). Professional bodies, including international organizations, state governments, and secretariats may use their own definitions.

United Nations The Food and Agriculture Organization (FAO) of the United Nations defines food loss and waste as the decrease in quantity or quality of food along the food supply chain. Within this framework, UN Agencies distinguish loss and waste at two different stages in the process:

Food loss occurs along the food supply chain from harvest/slaughter/catch up to, but not including, the sales level Food waste occurs at the retail and consumption level.

Important components of this definition include:

Food redirected to nonfood chains (including animal feed, compost, or recovery to bioenergy) is not counted as food loss or waste. Inedible parts are not considered as food loss or waste (these inedible parts are sometimes referred to as unavoidable food waste) Under Sustainable Development Goal 12, the Food and Agriculture Organization is responsible for measuring food loss, while the UN Environmental Program measures food waste.

European Union In the European Union (EU), food waste is defined by combining the definitions of food and waste, namely: "any substance or product, whether processed, partially processed or unprocessed, intended to be, or reasonably expected to be ingested by humans (...)" (including things such as drinks and chewing gum; excluding things such as feed, medicine, cosmetics, tobacco products, and narcotic or psychotropic substances) "which the holder discards or intends or is required to discard".

Previously, food waste was defined by directive 75/442/EEC as "any food substance, raw or cooked, which is discarded, or intended or required to be discarded" in 1975. In 2006, 75/442/EEC was repealed by 2006/12/EC, which defined waste as "any substance or object in the categories set out in Annex I which the holder discards or intends or is required to discard". Meanwhile, Article 2 of Regulation (EC) No. 178/2002 (the General Food Law Regulation), as amended on 1 July 2022, defined food as "any substance or product, whether processed, partially processed or unprocessed, intended to be, or reasonably expected to be ingested by humans (...)", including things such as drinks and chewing gum, excluding things such as feed, medicine, cosmetics, tobacco products, and narcotic or psychotropic substances.

A 2016 European Court of Auditors special report had criticised the lack of a common definition of food waste as hampering progress, and a May 2017 resolution by the European Parliament supported a legally binding definition of food waste. Finally, the 2018/851/EU directive of 30 May 2018 (the revised Waste Framework Directive) combined the two (after waste was redefined in 2008 by Article 3.1 of 2008/98/EC as "any substance or object which the holder discards or intends or is required to discard") by defining food waste as "all food as defined in Article 2 of Regulation (EC) No 178/2002 of the European Parliament and of the Council that has become waste."

United States

As of 2022, the United States Environmental Protection Agency (EPA) employed three categories:"Excess food refers to food that is recovered and donated to feed people. Food waste refers to food such as plate waste (i.e., food that has been served but not eaten), spoiled food, or peels and rinds considered inedible that is sent to feed animals, to be composted or anaerobically digested, or to be landfilled or combusted with energy recovery. Food loss refers to unused product from the agricultural sector, such as unharvested crops." "Excess food refers to food that is recovered and donated to feed people." "Food waste refers to food such as plate waste (i.e., food that has been served but not eaten), spoiled food, or peels and rinds considered inedible that is sent to feed animals, to be composted or anaerobically digested, or to be landfilled or combusted with energy recovery." "Food loss refers to unused product from the agricultural sector, such as unharvested crops."

In 2006, the EPA defined food waste as "uneaten food and food preparation wastes from residences and commercial establishments such as grocery stores, restaurants, produce stands, institutional cafeterias and kitchens, and industrial sources like employee lunchrooms".

The states remain free to define food waste differently for their purposes,"Food Material" means any material that was acquired for animal or human consumption, is separated from the municipal solid waste stream, and that does not meet the definition of "agricultural material." though as of 2009, many had not done so."Many states surveyed for this paper do not define food waste or distinguish between pre-consumer and post consumer food waste, while other states classify food waste types."

Methodology The 2019 FAO report stated: "Food loss and waste has typically been measured in physical terms using tonnes as reporting units. This measurement fails to account for the economic value of different commodities and can risk attributing a higher weight to low-value products just because they are heavier. [This] report acknowledges this by adopting a measure that accounts for the economic value of produce."

Hall et al. (2009) calculated food waste in the United States in terms of energy value "by comparing the US food supply data with the calculated food consumed by the US population." The result was that food waste among American consumers increased from "about 30% of the available food supply in 1974 to almost 40% in recent years" (the early 2000s), or about 900 kcal per person per day (1974) to about 1400 kcal per person per day (2003). A 2012 Natural Resources Defense Council report interpreted this to mean that Americans threw away up to 40% of food that was safe to eat. Buzby & Hyman (2012) estimated both the total weight (in kg and lbs) and monetary value (in USD) of food loss in the United States, concluding that "the annual value of food loss is almost 10% of the average amount spent on food per consumer in 2008".

Net animal losses Another approach to measuring food waste are "net animal losses" – the difference between the calories in human-edible crops fed to animals and the calories returned in meat, dairy and fish. These losses are higher than all conventional food losses combined. This is because livestock eat more human-edible food than their products provide. Research estimated that if the US would eat all human-edible food instead of feeding it to animals in order to eat their meat, dairy and eggs, it would free up enough food for an additional 350 million people. At a global level livestock is fed an average of 1738 kcal/person/day of human-edible food, and just 594 kcal/p/d of animal products return to the human food supply, a net loss of 66%.

Sources

Production In the United States, food loss can occur at most stages of the food industry and in significant amounts. In subsistence agriculture, the amounts of food loss are unknown, but are likely to be insignificant by comparison, due to the limited stages at which loss can occur, and given that food is grown for projected need as opposed to a global marketplace demand."... there is certainly a lot of waste in the system ... Unless, that is, we were to go back to subsistence agriculture …" Nevertheless, on-farm losses in storage in developing countries, particularly in African countries, can be high although the exact nature of such losses is much debated.

In the food industry of the United States, the food supply of which is the most diverse and abundant of any country in the world, loss occurs from the beginning of food production chain. From planting, crops can be subjected to pest infestations and severe weather, which cause losses before harvest. Since natural forces (e.g. temperature and precipitation) remain the primary drivers of crop growth, losses from these can be experienced by all forms of outdoor agriculture. On average, farms in the United States lose up to six billion pounds of crops every year because of these unpredictable conditions. According to the IPCC sixth assessment report, encouraging the development of technologies that address issues in food harvesting and post-harvesting could have a significant impact on decreasing food waste in the supply chain early-on.

The use of machinery in harvesting can cause losses, as harvesters may be unable to discern between ripe and immature crops, or collect only part of a crop. Economic factors, such as regulations and standards for quality and appearance, also cause food waste; farmers often harvest selectively via field gleaning, preferring to not waste crops "not to standards" in the field (where they can still be used as fertilizer or animal feed), since they would otherwise be discarded later. This method of removing undesirable produce from harvest collection, distribution sites and grocery stores is called culling. However, usually when culling occurs at the production, food processing, retail and consumption stages, it is to remove or dispose of produce with a strange or imperfect appearance rather than produce that is spoiled or unsafe to eat. In urban areas, fruit and nut trees often go unharvested because people either do not realize that the fruit is edible or they fear that it is contaminated, despite research which shows that urban fruit is safe to consume.

Food processing