Food waste

Food waste or food loss is food that is not eaten. The causes of food waste or loss are numerous and occur at the stages of production, processing, retail and consumption.
Global food loss and waste amount to between one-third and one-half of all food produced. Loss and wastage occur at all stages of the food supply chain or value chain. In low-income countries, most loss occurs during production, while in developed countries much food – about per person per year – is wasted at the consumption stage.


Food waste may occur at any stage of the food supply chain – production, processing, retail and consumption. Precise definitions are contentious, often defined on a situational basis. Professional bodies, including international organizations, state governments and secretariats may use their own definitions.
Among other things, in what food waste consists of, how it is produced, and where or what it is discarded from or generated by. Definitions also vary because certain groups do not consider food waste to be a waste material, due to its applications. Some definitions of what food waste consists of are based on other waste definitions and which materials do not meet their definitions.
Lost food may go to landfills, be put back into the food supply chain, or be put to other nonfood productive uses.

United Nations

Under the UN's Save Food initiative, the FAO, UNEP, and stakeholders have agreed on the following definition of food loss and waste:
Important components of this definition include:
In the European Union, food waste was defined as "any food substance, raw or cooked, which is discarded, or intended or required to be discarded" since 1975 until 2000 when the old directive was repealed by Directive 2008/98/EC, which has no specific definition of food waste. The directive, 75/442/EEC, containing this definition was amended in 1991 with the addition of "categories of waste" and the omission of any reference to national law.

United States

The United States Environmental Protection Agency defines food waste for the United States such as "uneaten food and food preparation wastes from residences and commercial establishments such as grocery stores, restaurants, and produce stands, institutional cafeterias and kitchens, and industrial sources like employee lunchrooms". The states remain free to define food waste differently for their purposes, though many choose not to. According to the Natural Resources Defense Council, Americans throw away up to 40% of food that is safe to eat.

Other definitions

The definitions by the UN and EU have come under criticism for including food that goes to nonfood productive use in their definitions of food waste. According to the authors of one study, this is flawed for two reasons: "First, if recovered food is used as an input, such as animal feed, fertilizer, or biomass to produce output, then by definition it is not wasted. However, there might be economic losses if the cost of recovered food is higher than the average cost of inputs in the alternative, nonfood use. Second, the definition creates practical problems for measuring food waste because the measurement requires tracking food loss in every stage of the supply chain and its proportion that flows to nonfood uses." The authors of the study argue that only food that ends up in landfills should be counted as food waste.



In the US, food waste can occur at most stages of the food industry and in significant amounts. In subsistence agriculture, the amounts of food waste are unknown, but are likely to be insignificant by comparison, due to the limited stages at which waste can occur, and given that food is grown for projected need as opposed to a global marketplace demand. 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, waste 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 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. The use of machinery in harvesting can cause waste, 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, preferring to leave crops not to standard in the field, since they would otherwise be discarded later. This method of removing undesirable produce from harvest collection, distribution sites and grocery stores is called Culling. The USDA defines culling as “the individual removal of genetically undesirable, inferior, weak, diseased, or infested plants from a planting in order to ensure the level of genetic purity or vigor of the crop”. 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 don't 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

Food waste continues in the post-harvest stage, but the amounts of post-harvest loss involved are relatively unknown and difficult to estimate. Regardless, the variety of factors that contribute to food waste, both biological/environmental and socio-economical, would limit the usefulness and reliability of general figures. In storage, considerable quantitative losses can be attributed to pests and micro-organisms. This is a particular problem for countries that experience a combination of heat and ambient humidity, as such conditions encourage the reproduction of insect pests and micro-organisms. Losses in the nutritional value, caloric value and edibility of crops, by extremes of temperature, humidity or the action of micro-organisms, also account for food waste. Further losses are generated in the handling of food and by shrinkage in weight or volume.
Some of the food waste produced by processing can be difficult to reduce without affecting the quality of the finished product. Food safety regulations are able to claim foods which contradict standards before they reach markets. Although this can conflict with efforts to reuse food waste, safety regulations are in place to ensure the health of the consumer; they are vitally important, especially in the processing of foodstuffs of animal origin, as contaminated products from these sources can lead to and are associated with microbiological and chemical hazards.


protects food from damage during its transportation from farms and factories via warehouses to retailing, as well as preserving its freshness upon arrival. Although it avoids considerable food waste, packaging can compromise efforts to reduce food waste in other ways, such as by contaminating waste that could be used for animal feedstocks.
In 2013 the non-profit Natural Resources Defense Council performed research that they state suggests that the leading cause of food waste in America is due to uncertainty over food expiration dates, such as confusion in deciphering best before, sell-by or use-by dates. Joined by Harvard Law, the NRDC produced a study called The Dating Game: How Confusing Food Date Labels Leads to Food Waste in America. This United States-based study looked at the intertwining laws which lead labeling to end up unclear and erratic. This uncertainty leads to consumers to toss food, most often because they think the food may be unsafe or misunderstand the labeling on the food completely. Lack of regulation on labeling can result in large quantities of food being removed from the market overall.
Retail stores throw away large quantities of food. Usually, this consists of items that have reached either their best before, sell-by or use-by dates. Food that has passed the best before, and sell-by date, and even some food that passed the use-by date is still edible at the time of disposal, but stores have widely varying policies to handle the excess food. Some stores put effort into preventing access to poor or homeless people, while others work with charitable organizations to distribute food. Retailers also contribute to waste as a result of their contractual arrangements with suppliers. Failure to supply agreed quantities renders farmers or processors liable to have their contracts cancelled. As a consequence, they plan to produce more than actually required to meet the contract, to have a margin of error. Surplus production is often simply disposed of.
Retailers usually have strict cosmetic standards for produce, and if fruits or vegetables are misshapen or superficially bruised, they are often not put on the shelf. In the United States, an estimated six billion pounds of produce is wasted each year because of its appearance. The USDA publishes guidelines used as a baseline assessment by produce distributors, grocery stores, restaurants and other consumers in order to rate the quality of food. These guidelines and how they rate are readily available on their website. For example, apples get graded by their size, color, wax residue, firmness, and skin appearance. If an apples rank highly in these categories and show close to no superficial defects, they are rated as “U.S. Extra Fancy” or “U.S. Fancy”, these are the typical ratings sought out by grocery stores when purchasing their produce. Any apples with suboptimal levels of appearance are ranked as either “U.S. Number 1” or “Utility” and are not normally purchased for retail, as recommended by produce marketing sources, despite being safe and edible.
The fish industry also contributes to the annual amount of food waste because of cosmetic standards that the fish are held up to. Nearly "2.3 million tonnes of fish discarded in the North Atlantic and the North Sea each year." Approximately 40 to 60 percent of "all fish caught in Europe is discarded – either because they are the wrong size or species." Addressing this, there are many campaigns focused on raising retailer and consumer awareness about food that fails to meet certain standards for appearance.


Consumers are directly and indirectly responsible for wasting a lot of food, which could for a large part be avoided if they were willing to accept suboptimal food that deviates in sensory characteristics or has a best-before date that is approaching or has passed, but is still perfectly fine to eat. COSUS is a SUSFOOD ERA-net research project under the topic 'Understanding consumer behaviour to encourage a sustainable food choice'. There are organizations around the country working to rescue and redistribute food to those in need. Many of these rely on volunteer support. Some of them are Feeding America, Food Recovery Network and Community Plates.


Global extent

The 2011 SIK study estimated the total of global food loss and waste to around one third of the edible parts of food produced for human consumption, amounting to about per year. As the following table shows, industrialized and developing countries differ substantially. In developing countries, it is estimated that 400–500 calories per day per person are going to waste, while in developed countries 1,500 calories per day per person are wasted. In the former, more than 40% of losses occur at the postharvest and processing stages, while in the latter, more than 40% of losses occur at the retail and consumer levels. The total food waste by consumers in industrialized countries is almost equal to the entire food production in sub-Saharan Africa.
Food loss and waste per person per yearTotalAt the production
and retail stages
By consumers
North America and Oceania
Industrialized Asia
sub-Saharan Africa
North Africa, West and Central Asia
South and Southeast Asia
Latin America

A 2013 report from the British Institution of Mechanical Engineers likewise estimated that 30–50% of all food produced remains uneaten.

Individual countries


Each year in New South Wales, more than 25 million meals are delivered by charity OzHarvest from food that would otherwise be wasted. Each year, the Australian economy loses $20 billion in food Waste. This has a crucial environmental impact through the waste of resources used to produce, manufacture, package and distribute that food.
In addition, it is estimated that 7.6 million tonnes of CO2 is generated by the disposed food in landfills. It is also the cause of odour, leaching and potential generation for diseases. In march 2019, the Australian ministry of the environment shared the key findings of Australia’s National food waste baseline, which will facilitate the tracking of the progress towards their goal to halve Australian food waste by 2030.
Many initiatives were taken on by the Australian government in order to help achieve this goal. In fact, they financed $1.2 million in organizations that invest in renewable energies systems to store and transport food. They also funded more than $10 million for research on food waste reduction. Local governments have also implemented programs such as information sessions on storing food and composting, diversion of waste from restaurants and cafes from landfills to shared recycling facilities and donation of food to organizations that would otherwise be wasted.


In Canada, 58% of all food is wasted, amounting to 35.5 million tonnes of food per annuum. The value of this lost food is equivalent to CA$21 billion. Such quantities of food would be enough to feed all Canadians for five months. It is estimated that about one third of this waste could be spared and sent to those in need. There are many factors that contribute so such large-scale waste. Manufacturing and processing food alone incur costs of CA$21 billion, or 4.82 million tons. Per household, it is estimated that $1,766 is lost in food loss and waste. The Government of Canada identifies three main factors contributing to household waste: buying too much food and not eating it before it spoils, malfunctioning or poorly-designed packaging that does not deter spoilage rates or contamination, and improper disposing of food – using garbage bins instead of those intended for organic waste.
Canada, Mexico, and the United States are working together under the Commission for Environmental Cooperation in order to address the severe problem of food waste in North America.
Canada specifically is working in the following ways to reduce food waste:
According to Ministry of Environment, over 700,000 tonnes per year of food is wasted every year in Denmark in the entire food value chain from farm to fork. Due to the work of activist Selina Juul's Stop Wasting Food movement, Denmark has achieved a national reduction in food waste by 25% in 5 years.


In France, approximately 1.3–1.9 million tonnes of food waste is produced every year, or between 20 and 30 kilograms per person per year. Out of the 10 million tonnes of food that is either lost or wasted in the country, 7.1 million tonnes of food wasted in the country, only 11% comes from supermarkets. Not only does this cost the French €16 billion per year, but also the negative impact on the environment is also shocking. In France, food waste emits 15.3 million tonnes of CO2, which represents 3% of the country’s total CO2 emission. In response to this issue, France has become the first country in the world to pass a unanimous legislation that bans supermarkets from throwing away or destroying unsold food. Instead, supermarkets are expected to donate such food to charities and food banks. In addition to donating food, many businesses claim to prevent food waste by selling soon-to-be wasted products at discounted prices. in France has outlined eleven measures to achieve a food waste reduction by half by 2025.


According to the research of National Food Chain Safety Office, an average Hungarian consumer generates 68 kg food waste annually. 49% of this amount would be avoidable.


According to a publication of Wageningen University and Research report it is estimated that in the Netherlands, between 30% and 50% of all food produced is lost or thrown away. In total, people in the Netherlands waste at least 9.5m tonnes of food per year, worth at least €4.4bn.

New Zealand


In Singapore, of food was wasted in 2014. Of that, were recycled. Since Singapore has limited agriculture ability, the country spent about S$14.8 billion on importing food in 2014. US$1.4 billion of it ends up being wasted, or 13 percent.

United Kingdom

In the UK, per year of wasted food amounts to a cost of £10.2 billion each year. This represents costs of £250 to £400 a year per household.

United States

Estimates of food waste in the United States range from 35 million tons to 103 million tons. In a study done by National Geographic in 2014, Elizabeth Royte indicated more than 30 percent of food in the United States, valued at $162 billion annually, isn't eaten. The University of Arizona conducted a study in 2004, which indicated that 14 to 15% of United States edible food is untouched or unopened, amounting to $43 billion worth of discarded, but edible, food. In 2010, the United States Department of Agriculture has come forth with estimations from the Economic Research Service that approximates food waste in the United States to be equivalent to 141 trillion calories.

Impact on the environment

According to the Food and Agriculture Organization, food waste is responsible for 8 percent of global human-made greenhouse gas emissions. The FAO concludes that nearly 30 percent of all available agricultural land in the world - 1.4 billion hectares - is used for produced but uneaten food. The global blue water footprint of food waste is 250 km3, that is the amount of water that flows annually through the Volga or 3 times Lake Geneva.


Response to the problem of food waste at all social levels has varied hugely, including campaigns from advisory and environmental groups, and concentrated media attention on the subject.

Consumer marketing

One way of dealing with food waste is to reduce its creation. Consumers can reduce spoilage by planning their food shopping, avoiding potentially wasteful spontaneous purchases, and storing foods properly. Widespread educational campaigns have been shown to be an effective way to reduce food waste. A British campaign called “Love Food, Hate Waste” has raised awareness about preventative measures to address food waste for consumers. Through advertisements, information on food storage and preparation and in-store education, the UK observed a 21% decrease in avoidable household food waste over the course of 5 years. Another potential solution is for "smart packaging" which would indicate when food is spoiled more precisely than expiration dates currently do, for example with temperature-sensitive ink, plastic that changes color when exposed to oxygen, or gels that change color with time.
An initiative in Curitiba, Brazil called Cambio Verde allows farmers to provide surplus produce to people that bring glass and metal to recycling facilities. In Europe, the Food Surplus Entrepreneurs Network, coordinates a network of social businesses and nonprofit initiatives with the goal to spread best practices to increase the use of surplus food and reduction of food waste.


In areas where the waste collection is a public function, food waste is usually managed by the same governmental organization as other waste collection. Most food waste is combined with general waste at the source. Separate collections, also known as source-separated organics, have the advantage that food waste can be disposed of in ways not applicable to other wastes. In the United States, companies find higher and better uses for large commercial generators of food and beverage waste.
From the end of the 19th century through the middle of the 20th century, many municipalities collected food waste separately. This was typically disinfected by steaming and fed to pigs, either on private farms or in municipal piggeries.
Separate curbside collection of food waste is now being revived in some areas. To keep collection costs down and raise the rate of food waste segregation, some local authorities, especially in Europe, have introduced "alternate weekly collections" of biodegradable waste, which enable a wider range of recyclable materials to be collected at reasonable cost, and improve their collection rates. However, they result in a two-week wait before the waste will be collected. The criticism is that particularly during hot weather, food waste rots and stinks, and attracts vermin. Waste container design is therefore essential to making such operations feasible. Curbside collection of food waste is also done in the U.S., some ways by combining food scraps and yard waste together. Several states in the U.S. have introduced a yard waste ban, not accepting leaves, brush, trimmings, etc. in landfills. Collection of food scraps and yard waste combined is then recycled and composted for reuse.


Food waste from restaurants and catering companies can be shredded and the slurry used for production of biogas by anaerobic fermentation. It has been suggested that degradation and long retention time in the transportation chain may alter the hazardous properties of the food waste slurry, in particular its ability to release poisonous hydrogen sulphide.


As alternatives to landfill, food waste can be composted to produce soil and fertilizer, fed to animals or insects, or used to produce energy or fuel. Some wasted fruit parts,... can also be biorefined to extract useful substances for the industry.

Landfills and greenhouse gases

Dumping food waste in a landfill causes odour as it decomposes, attracts flies and vermin, and has the potential to add biological oxygen demand to the leachate. The European Union Landfill Directive and Waste Regulations, like regulations in other countries, enjoin diverting organic wastes away from landfill disposal for these reasons. Starting in 2015, organic waste from New York City restaurants will be banned from landfills.
In countries such as the United States and the United Kingdom, food scraps constitute around 19% of the waste buried in landfills, where it biodegrades very easily and produces methane, a powerful greenhouse gas.
Methane, or CH4, is the second most prevalent greenhouse gas that is released into the air, also produced by landfills in the U.S. Although methane spends less time in the atmosphere than CO2, it's more efficient at trapping radiation. It is 25 times greater to impact climate change than CO2 in a 100-year period. Humans accounts over 60% of methane emissions globally.

Fodder and insect feed

Large quantities of fish, meat, dairy and grain are discarded at a global scale annually, when they can be used for things other than human consumption. The feeding of food scraps to domesticated animals such as pigs or chickens is, historically, the most common way of dealing with household food waste. The animals turn roughly two thirds of their ingested food into gas or fecal waste, while the last third is digested and repurposed as meat or dairy products. There are also different ways of growing produce and feeding livestock that could ultimately reduce waste.
Bread and other cereal products discarded from the human food chain could be used to feed chickens. Chickens have traditionally been given mixtures of waste grains and milling by-products in a mixture called chicken scratch. As well, giving table scraps to backyard chickens is a large part of that movement's claim to sustainability, though not all backyard chicken growers recommend it. Ruminants and pigs have also been fed bakery waste for a long time.
Certain food waste can also be used as feed in maggot farming. The maggots can then be fed to other animals. In China, some food waste is being processed by feeding it to cockroaches. Also, black soldier fly larvae can be grown on food waste.


Food waste can be biodegraded by composting, and reused to fertilize soil. Composting is the aerobic process completed by microorganisms in which the bacteria break down the food waste into simpler organic materials that can then be used in soil. By redistributing nutrients and high microbial populations, compost reduces water runoff and soil erosion by enhancing rainfall penetration, which has been shown to reduce the loss of sediment, nutrients, and pesticide losses to streams by 75–95%.
Traditional composting uses microbes to perform the decomposition, a process that is most efficient using low, mid, and high temperature microbes. The high temperatures required by the thermophilic microorganisms are hot enough to kill pathogens, making the product of this traditional composting satisfactory for use in soil according to the United States Environmental Protection Agency's standards. The traditional decomposition process requires a long length of time and additional energy expended to turn the material frequently and maintain the aerobic process. Composting by thermophilic microbes can lead to nutrient loss and the compost product is heterogeneous, with the potential for higher levels of contaminants which can be harmful if used in agriculture. An alternate method of composting is vermicomposting.
Vermicomposting is the practise of feeding scraps to worms who produce fertilized soil as a byproduct. The process of composting using earth worms is completed in a short duration of time and requires no additional energy to turn and maintain aerobic processes, as these actions are already performed by the worms. In order to keep the worms alive, the environment has to be kept below 35° Celsius, therein making this compost ineligible for use in agriculture according to the EPA standards. The product of vermicomposting is homogenous and generally contains lower levels of contaminants than traditional composting. Some look to integrate vermicomposting and traditional composting in an effort to maximize efficiency while producing a high quality organic product that can be used in agriculture.
Composting food waste leads to a decrease in the quantity of greenhouse gases released into the atmosphere. In landfills, organic food waste decomposes anaerobically, producing methane gas that is emitted into the atmosphere. When this biodegradable waste is composted, it decomposes aerobically and does not produce methane, but instead produces organic compost that can then be utilized in agriculture. Recently, the city of New York has begun to require that restaurants and food-producing companies begin to compost their leftover food. Another instance of composting progress is a Wisconsin-based company called WasteCap, who is dedicated towards aiding local communities create composting plans.
Municipal Food Waste can be composted to create this product of organic fertilizer, and many municipalities choose to do this citing environmental protection and economic efficiency as reasoning. Transporting and dumping waste in landfills requires both money and room in the landfills that have very limited available space. One municipality who chose to regulate MFW is San Francisco, who requires citizens to separate compost from trash on their own, instituting fines for non-compliance at $100 for individual homes and $500 for businesses. The city's economic reasoning for this controversial mandate is supported by their estimate that one business can save up to $30000 annually on garbage disposal costs with the implementation of the required composting. Composting is an economical and environmentally conscious step many homeowners could take to reduce their impact on landfill waste. Instead of food scraps and spoiled food taking up space in trashcans or stinking up the kitchen before the bag is full, it could be put outside and broken down by worms and added to garden beds.

Anaerobic digestion

produces both useful gaseous products and a solid fibrous "compostable" material. Anaerobic digestion plants can provide energy from waste by burning the methane created from food and other organic wastes to generate electricity, defraying the plants' costs and reducing greenhouse gas emissions.The United States Environmental Protection Agency states that the use of anaerobic composting allows for large amounts of food waste to avoid the landfills. Instead of producing these greenhouse gasses into the environment from being in a landfill, the gasses can alternatively be harnessed in these facilities for reuse.
Since this process of composting produces high volumes of biogas, there are potential safety issues such as explosion and poisoning. These interactions require proper maintenance and personal protective equipment is utilized. Certain U.S. states, such as Oregon, have implemented the requirement for permits on such facilities, based on the potential danger to the population and surrounding environment.
Food waste coming through the sanitary sewers from garbage disposal units is treated along with other sewage and contributes to sludge.

Commercial liquid food waste

Commercially, food waste in the form of wastewater coming from commercial kitchens’ sinks, dishwashers and floor drains is collected in holding tanks called grease interceptors to minimize flow to the sewer system. This often foul-smelling waste contains both organic and inorganic waste and may also contain hazardous hydrogen sulfide gases. It is referred to as fats, oils, and grease waste or more commonly "brown grease" and is an overwhelming problem, especially in the US, for the aging sewer systems. Per the US EPA, sanitary sewer overflows also occur due to the improper discharge of FOGs to the collection system. Overflows discharge – of untreated wastewater annually into local waterways, and up to 3,700 illnesses annually are due to exposure to contamination from sanitary sewer overflows into recreational waters.

Agricultural food waste

Nearly all global produce, eaten or disposed of is grown using irrigated water. Irrigated water represents the largest sector of water withdraws worldwide, with as much as 90% of total water withdraws being allocated towards agricultural usage. Food which goes uneaten can account for vast quantities of water waste, with food waste being the largest area the average US citizen contributes to water waste.