Generally, food loss or food waste is food that is discarded or lost uneaten. However, precise definitions are contentious, 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.
Definitions of food waste vary, 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 (or have traditionally not considered) 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 (e.g. agricultural waste) and which materials do not meet their definitions.
Under the UN's Save Food initiative, the FAO, UNEP and stakeholders have agreed the following definition of food loss and waste:Food loss is the decrease in quantity or quality of food. Food loss in the production and distribution segments of the food supply chain is mainly a function of the food production and supply system or its institutional and legal framework.
Food waste (which is a component of food loss) is any removal of food from the food supply chain which is or was at some point fit for human consumption, or which has spoiled or expired, mainly caused by economic behaviour, poor stock management or neglect.
Important components of this definition include:Food waste is a part of food loss, but the distinction between the two is not clearly defined
Food redirected to non-food chains (including animal feed, compost or recovery to bioenergy) is counted as food loss or waste.
Plants and animals produced for food contain 'non-food parts' which are not included in 'food loss and waste' (these inedible parts are sometimes referred to as 'unavoidable food waste'
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cooked, which is discarded, or intended or required to be discarded" since 1975 until 2000 when the old directive was repealed by Directive 2008/98/EC, which has no specific definition of food waste.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 (91/156) with the addition of "categories of waste" (Annex I) and the omission of any reference to national law.
In July 2014, the European Commission has announced its targets for the circular economy, waste management and provided a "food waste" definition as "food (including inedible parts) lost from the food supply chain, not including food diverted to material uses such as bio-based products, animal feed, or sent for redistribution" (i.e. food donation). Concurrently, all Member States of the European Union shall establish frameworks to collect and report levels of food waste across all sectors in a comparable way. The latest data are requested to develop national food waste prevention plans, aimed to reach the objective to reduce food waste by at least 30% between 1 January 2017 and 31 December 2025. To enable the process, the Commission shall adopt implementing acts by 31 December 2017 in order to establish uniform conditions for monitoring the implementation of food waste prevention measures taken by Member States of the EU.
The United States Environmental Protection Agency defines food waste for the United States 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.
In developing and developed countries which operate either commercial or industrial agriculture, 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.
Research into the food industry of the United States, whose food supply is the most diverse and abundant of any country in the world, found food waste occurring at the beginning of food production. 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. 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 (where they can be used as fertilizer or animal feed), since they would otherwise be discarded later. 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 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 (around 30 °C) and ambient humidity (between 70 and 90 per cent), 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; these "qualitative losses" are more difficult to assess than quantitative ones. 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 (such as in animal feed), 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 (e.g. meat and dairy products), as contaminated products from these sources can lead to and are associated with microbiological and chemical hazards.
Packaging 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.
Retail stores can throw away large quantities of food. Usually, this consists of items that have reached their either their best before, sell-by or use-by dates. Food that 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.
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. In a study done in 2009, it was estimated that nearly 20 to 40 percent of fruit and vegetables in the UK alone are rejected before they even reach retailers, as a result of high cosmetic standards.
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 (are) 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.
Empirical evidence show that drivers of consumer food waste, even in a low-middle income context, include: (1) stocking too much food; (2) over-preparing or not cooking it properly (e.g. burning food); (3) leaving food on dishes after meals or not willing to consume leftovers; and (4) decaying of prepared food after long or inappropriate storage. Excessive purchasing, over-preparation and unwillingness to consume leftovers are some of the main antecedents of food waste. As author Gustavo Porpino states, "they are embedded in cultural practices such as hospitality, the good mother identity, taste for abundance, and food seen as wealth".
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 1.3 billion tonnes (1.28×109 long tons; 1.43×109 short tons) 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 (222 million tonnes or 218,000,000 long tons or 245,000,000 short tons) is almost equal to the entire food production in sub-Saharan Africa (230 million tonnes or 226,000,000 long tons or 254,000,000 short tons).
A 2013 report from the British Institution of Mechanical Engineers (IME) likewise estimated that 30–50% (or 1.2–2 billion tonnes or 1.18×109–1.97×109 long tons or 1.32×109–2.20×109 short tons ) of all food produced remains uneaten.
In Singapore, 788,600 tonnes (776,100 long tons; 869,300 short tons) of food was wasted in 2014. Of that, 101,400 tonnes (99,800 long tons; 111,800 short tons) were recycled. Since Singapore has limited agriculture ability, the country spent about S$14.8 billion (US$10.6 billion) on importing food in 2014. US$1.4 billion of it ends up being wasted, or 13 percent.
In the UK, 6,700,000 tonnes (6,590,000 long tons; 7,390,000 short tons) per year of wasted food (purchased and edible food which is discarded) amounts to a cost of £10.2 billion each year. This represents costs of £250 to £400 a year per household.
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. Another survey, by the Cornell University Food and Brand Lab, found that 93 percent of respondents acknowledged buying foods they never used.
According to Ministry of Environment (Denmark), 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 (2010–2015).
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.
As alternatives to landfill, food waste can be composted to produce soil and fertilizer, fed to animals, or used to produce energy or fuel. Companies like Skip Shapiro Enterprises LLC find beneficial reuses for food waste throughout North Americs and beyond.
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. 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 (produce they would otherwise discard due to too low prices) to people that bring glass and metal to recycling facilities (to encourage further waste reduction). In Europe, the Food Surplus Entrepreneurs Network (FSE 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.
Dumping food waste in a landfill causes odour as it decomposes, attracts flies and vermin, and has the potential to add biological oxygen demand (BOD) 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 dumped in landfills, where it ends up rotting and producing methane, a greenhouse gas.
In a study done on Italy in 2014, it was estimated that food waste from 'farm to fork' emits nearly 4 million tons of CO2. The country produces 186,000 tons of oil equivalent annually.
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 (12 years) 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.
In areas where 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 wastes 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 (called "garbage" as opposed to "trash") 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 (including, e.g., garden 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.
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 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.
One of the common animals to be fed household scraps is swine, in which case the food scraps are often called slop. A study done in 2009 suggests approximately 20 times more CO2 can be saved by feeding food waste to pigs, instead of allowing it to go through anaerobic digestion. Some European laws restrict the amount and type of scraps that can be fed to pigs. However, in countries such as Japan, South Korea and Taiwan, it is encouraged and furthermore mandatory to feed certain food waste to pigs.
The amount of bread and other cereal products discarded in UK households, has been indicated to be enough to "lift 30 million of the world's hungry people out of malnourishment." These grains, wasted for different reasons (including, e.g., over production) could have otherwise been 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.
Certain food waste (such as flesh) can also be used as feed in maggot farming. The maggots can then be fed to other animals.
Food waste can be biodegraded by composting, and reused to fertilize 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%.
Vermicomposting is the practise of feeding scraps to worms who produce fertilized soil as a byproduct.
Food waste can be composted at home, avoiding central collection entirely, and many local authorities have schemes to provide subsidised composting bin systems. However, the proportion of the population willing to dispose of their food waste in that way may be limited.
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.
Food waste coming through the sanitary sewers from garbage disposal units is treated along with other sewage and contributes to sludge.
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 (chemical cleaners, etc.) and may also contain hazardous hydrogen sulfide gases. It is referred to as fats, oils, and grease (FOG) waste or more commonly "brown grease" (versus "yellow grease", which is fryer oil that is easily collected and processed into biodiesel) and is an overwhelming problem, especially in the USA, 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 3 billion US gallons (11,000,000 m3) - 10 billion US gallons (38,000,000 m3) 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.
In US metropolitan areas, the brown grease is taken by pumpers or grease-hauling trucks to wastewater treatment plants, where they are charged to dump it. In other areas, it may be taken to a landfill or it may be illegally dumped somewhere unknown, to avoid charges. This unmonitored disposal process is not only harmful for our environment and our health, but it also hurts businesses which have no idea where their business waste ends up, or indeed how much liquid waste is in their grease interceptors at any point in time, leaving them vulnerable to illegal dumping into their own grease traps or interceptors. Some companies now market computerized monitoring services along with in situ bioremediation, which produces byproducts of CO2 and gray water that can safely flow into sewer systems. Other new technologies offer ex situ treatment to process brown grease into some form of transportation fuel. This may not be as environmentally friendly as in situ treatment, since it still requires vehicles to pump and transport the brown grease waste to the plants.
Estimating how much brown grease food waste is produced annually is difficult, but in the US alone, number is thought to be in the billions of gallons. In 2009, the city of San Francisco stated it produces about 10 million US gallons (8,300,000 imp gal; 38,000 m3) of brown grease a year. It is starting the first citywide project in the US to recycle brown grease into biodiesel and other fuels.
Nearly all global produce, eaten or disposed of is grown using irrigated water. The irrigated water is taken from rivers, lakes, and wells by farmers amounting to roughly 675 litres. If the food goes uneaten, the water is ultimately wasted. To put it into perspective, this wasted water would "be enough for the domestic needs (at 200 litres per person per day) of 9 billion people."