Food loss and waste refers to food that is thrown away or not eaten. This happens at every stage of the food system, including production, processing, transportation, retail, food service, and consumption. Globally, about one-third of all food is wasted. This waste uses many resources used in food production. A 2021 study by the United Nations Environment Programme found that about 931 million tonnes of food are wasted each year worldwide, or about 121 kilograms per person. Of this waste, 61% comes from households, 26% from food service businesses, and 13% from retail stores.

Food waste can be reduced through prevention, such as using food preservation methods, or by reusing food, such as donating it to those in need. Food can also be used for animal feed or recycled. Throwing food in landfills should be avoided because it produces a large amount of methane, a powerful greenhouse gas. Reducing food waste across all parts of the food system helps lower the environmental impact of agriculture by reducing the use of water, land, and other resources.

Wasted food contributes significantly to agriculture's impact on climate change, producing the equivalent of 3.3 billion tons of carbon dioxide emissions each year. It also affects other environmental issues, such as land use, water use, and loss of biodiversity. Food waste conflicts with efforts to address food insecurity in some regions. The United Nations' Sustainable Development Goals aim to halve global per capita food waste at retail and consumer levels and reduce food losses along production and supply chains by 2030. At the 2022 United Nations Biodiversity Conference, nations agreed to cut food waste by 50% by 2030.

Definition

Food loss and waste happen at every step of the food supply chain, which includes production, processing, selling, and eating. The terms "food loss" and "food waste" are not always clearly defined. What counts as loss or waste, and which parts of food (like inedible parts) are considered lost or wasted, can vary. These terms are often defined based on the situation, just like how waste is generally defined. Different groups, such as international organizations, government agencies, and secretariats, may use their own definitions.

The Food and Agriculture Organization (FAO) of the United Nations defines food loss and waste as a decrease in the amount or quality of food along the food supply chain. According to the FAO, food loss happens from the time food is harvested, caught, or slaughtered up to, but not including, the point when it is sold. Food waste occurs at the retail and consumption stages, such as when food is thrown away by stores or consumers.

Important details in this definition include:
– Food that is sent to nonfood uses, such as animal feed, compost, or bioenergy, is not counted as food loss or waste.
– Inedible parts of food, like peels or bones, are not considered food loss or waste. These parts are sometimes called unavoidable food waste.

Under Sustainable Development Goal 12, the FAO measures food loss, while the United Nations Environment Program measures food waste.

In the European Union (EU), food waste is defined as any substance or product, whether processed or unprocessed, that is meant to be eaten by humans. This includes items like drinks and chewing gum but excludes things like animal feed, medicine, cosmetics, tobacco, and drugs. The EU previously used a different definition in 1975, which was replaced in 2006. A 2016 report by the European Court of Auditors pointed out that the lack of a clear definition for food waste made progress difficult. In 2017, the European Parliament supported creating a legally binding definition. In 2018, the EU updated its definition to include all food that has become waste, based on the definition of food from a 2002 regulation.

As of 2022, the United States Environmental Protection Agency (EPA) uses three categories:
– Excess food: Food that is recovered and given to people.
– Food waste: Food that is not eaten, such as leftovers, spoiled food, or inedible parts sent to animals, compost, or landfills.
– Food loss: Unused food from farming, like crops that are not harvested.

In 2006, the EPA defined food waste as uneaten food and food scraps from homes, stores, restaurants, and other places. States in the U.S. can define food waste differently for their own purposes, though many had not done so by 2009.

A 2019 FAO report noted that food loss and waste are often measured by weight, but this method does not consider the value of different foods. The report used a method that accounts for the economic value of food instead.

In 2009, Hall and others calculated food waste in the U.S. by comparing the total food supply to the amount of food people actually eat. They found that food waste increased from about 30% of the food supply in 1974 to nearly 40% by the early 2000s. A 2012 report estimated that up to 40% of safe-to-eat food in the U.S. was wasted. Another study in 2012 estimated that food loss in the U.S. was worth about 10% of the average amount spent on food per person in 2008.

Another way to measure food waste is by looking at "net animal losses," which compares the calories from human-edible food given to animals with the calories returned in meat, dairy, and fish. This method shows that feeding animals human-edible food results in a large loss of calories. Research suggests that if the U.S. used all human-edible food for people instead of feeding it to animals, it could provide enough food for an additional 350 million people. Globally, livestock consume about 1,738 calories of human-edible food per person per day but return only about 594 calories in animal products, creating a net loss of 66%.

Extent

The Food and Agriculture Organization (FAO) and the United Nations Environment Programme (UNEP) are working to track progress toward SDG Target 12.3 using two tools: the Food Loss Index (FLI) and the Food Waste Index (FWI).

According to FAO's The State of Food and Agriculture 2019, in 2016, about 14% of the world’s food was lost before reaching the retail level. Losses are often higher for fruits and vegetables than for cereals and pulses. However, significant losses still occur in sub-Saharan Africa and Eastern and South-Eastern Asia for cereals and pulses, while losses are lower in Central and Southern Asia.

UN Environment’s Food Waste Index estimates that in 2019, about 931 million tonnes of food, or 17% of the food available to consumers, was thrown away by households, retailers, restaurants, and other food services.

A report from Feedback EU states that the European Union wastes 153 million tonnes of food each year, which is about twice as much as earlier estimates.

In 2011, an FAO report based on research by The Swedish Institute for Food and Biotechnology (SIK) found that about one-third of all edible food produced for human consumption is lost or wasted globally, totaling about 1.3 billion tonnes per year. In developing countries, about 400–500 calories per person per day are wasted, mostly during post-harvest and processing stages. In developed countries, about 1,500 calories per person per day are wasted, mostly at retail and consumer levels. Food waste by consumers in industrialized countries (222 million tonnes) is nearly equal to the total food production in sub-Saharan Africa (230 million tonnes).

A 2013 report from the British Institution of Mechanical Engineers (IME) estimated that 30–50% (or 1.2–2 billion tonnes) of all food produced is not eaten.

In New South Wales, charity OzHarvest delivers over 25 million meals each year from food that would otherwise be wasted. Australia loses $20 billion annually due to food waste, which harms the environment by wasting resources used to produce, package, and distribute food. Composting and worm farming by food-growing families divert over 361,000 tonnes of food waste from landfills each year. Over 45% of Australians grow some of their own food, and more than half of households grow food, though yields are often low. Motivations for growing food include health benefits, better taste, and saving money.

It is estimated that 7.6 million tonnes of CO₂ are released annually from food waste in landfills, costing households $19.3 billion. This waste also causes bad smells, pollution, and risks for disease. In March 2019, Australia’s environment ministry shared findings from the National Food Waste Baseline, which will help track progress toward halving food waste by 2030.

The Australian government has taken steps to reduce food waste, including funding $1.2 million for renewable energy systems to store and transport food and $10 million for research on waste reduction. Local governments also offer programs like composting workshops, food donation initiatives, and waste diversion from landfills. Research shows people are more likely to reduce food waste for financial reasons than for altruistic ones, with households motivated by saving money wasting $100 less annually.

Coal mining and gas drilling disrupt important water sources, harming agriculture and ecosystems. These industries have released polluted water into rivers, with no clear solutions for managing waste from gas extraction. Long-term environmental and social effects have led to calls for stronger protections for food, water, and communities.

In Australia, 78% of people support clearer date labels on food, and 72% favor relaxed standards for food appearance. However, 81% believe individuals also share responsibility for reducing waste.

In Canada, 58% of all food is wasted, totaling 35.5 million tonnes per year, valued at CA$21 billion. This amount could feed all Canadians for five months. About one-third of this waste could be redirected to help those in need. Factors contributing to waste include buying too much food, poor packaging, and improper disposal. The Canadian government identifies three main causes of household waste: buying too much food and not eating it before it spoils, malfunctioning or poorly designed packaging, and improper disposal of food.

Canada, Mexico, and the United States are collaborating through the Commission for Environmental Cooperation to address food waste in North America.

Canada is taking specific steps to reduce waste, including:
– Pledging to develop strategies to reduce avoidable food waste as part of the Strategy on Short-lived Climate Pollutants, which will help reduce methane emissions from landfills.
– Implementing a Food Policy for Canada to create a more sustainable food system.
– Bringing together experts in 2019 to discuss ways to measure and reduce food waste across the supply chain.

During the 2022 Quebec general election, Québec solidaire party leader Gabriel Nadeau-Dubois stated that ending food waste would be a priority if the party gained power. The party aims to cut food waste by 50% by requiring large businesses and institutions to donate unsold food or send it to processing companies.

In 2015, the Chinese Academy of Sciences reported that large cities in China waste 17–18 million tonnes of food annually, enough to feed over 30 million people. About 25% of this waste is staple foods, and 18% is meat.

In August 2020, Chinese President Xi Jinping called food waste shocking and distressing. A campaign called "Operation empty plate" (光盘行动) was launched to reduce waste, including encouraging restaurants to limit orders to one fewer main dish per customer.

As of December 2020, a draft law is being considered in China to penalize food outlets that encourage or mislead customers into wasting food.

Impact

According to the United Nations, about one-third of all human-caused greenhouse gas emissions are connected to food production. Studies on the environmental impact of major food groups worldwide show that reducing land use should focus on meat and animal products, which make up 60% of the land footprint linked to food loss and waste. If the goal is to address water scarcity, cereals and pulses contribute the most (more than 70%), followed by fruits and vegetables. In terms of greenhouse gas emissions from food loss and waste, cereals and pulses are again the largest contributors (more than 60%), followed by roots, tubers, and oil-bearing crops. However, the environmental impact of different foods varies by region and country due to differences in crop yields and farming methods. According to the IPCC 6th Assessment Report, reducing food waste would help improve the availability of resources like water, land use, and energy consumption, while also lowering greenhouse gas emissions into the atmosphere.

The Universal Declaration of Human Rights states that "everyone has the right to a standard of living adequate for the health and well-being of himself and of his family, including food." Food waste and loss conflict with widespread global food insecurity. For example, food loss in Africa is estimated to be twice the amount of calories needed to address nutritional deficiencies. Meanwhile, the surplus of food consumed in the United States due to overeating could meet the caloric needs of people facing hunger in Africa.

Prevention

In 2022, the United Nations Biodiversity Conference helped countries agree to protect biodiversity. This agreement includes a goal to cut food waste by 50% by 2030.

According to the Food and Agriculture Organization (FAO) report The State of Food and Agriculture 2019, reducing food loss and waste can help society in several ways: (i) increase productivity and economic growth; (ii) improve food security and nutrition; and (iii) reduce the environmental harm caused by food waste, such as lowering greenhouse gas emissions and reducing pressure on land and water resources. The last two benefits are often seen as side effects of reducing food waste.

Efforts to solve the problem of food waste have varied across different levels of society. These include campaigns by advisory and environmental groups, as well as media attention on the issue.

The food waste hierarchy suggests that preventing food waste and reusing food for human consumption are the top priorities. The main ways to reduce food waste are prevention and valorisation. Prevention includes actions that stop food from being wasted, such as donating food or reprocessing it into new products. Valorisation involves using food waste to recover materials, nutrients, or energy, such as making animal feed, fuel, or energy from food waste.

Studies have shown that reducing food waste through prevention or valorisation for human use has greater environmental benefits than lower-priority methods like energy production or disposal.

Many initiatives help rescue food that would otherwise go uneaten. This food can come from supermarkets, restaurants, or homes. Examples include:
– Food banks,
– Online platforms like Too Good To Go and Olio,
– Public foodsharing shelves (e.g., foodsharing.de), and
– Dumpster diving.

One way to reduce food waste is to stop it from being created in the first place. Consumers can avoid spoilage by planning meals, avoiding unplanned purchases, and storing food properly. Educational campaigns have proven effective in reducing food waste.

A British campaign called "Love Food, Hate Waste" raised awareness about preventing food waste. It used advertisements, food storage tips, and in-store education. Over five years, this helped reduce avoidable household food waste in the UK by 21%.

Another idea is "smart packaging," which can show when food is spoiled more accurately than expiration dates. Examples include temperature-sensitive ink, plastic that changes color when exposed to oxygen, or gels that change color over time.

In Curitiba, Brazil, a program called Cambio Verde lets farmers give surplus produce to people who bring glass or metal to recycling centers. This encourages recycling and reduces waste. In Europe, the Food Surplus Entrepreneurs Network (FSE Network) connects social businesses and nonprofits to share best practices for using surplus food and reducing waste.

Most experts agree that reducing food waste has major environmental benefits. However, reducing waste might lead to people buying more food because they save money, which could reduce some of the environmental benefits.

For many cultures around the world, food preservation techniques have been used for a long time to avoid waste and ensure survival. Today, overproduction has led to large amounts of food waste. It is important to recognize traditional methods that help reduce waste in homes.

In Africa, food loss is a big problem, often because of poor preservation. For example, in sub-Saharan Africa, more than 40% of food is lost after harvest and during processing. The Journal of Food Security suggests that using traditional African knowledge about food processing, preservation, and storage can improve food security. In Nigeria, methods like sun drying, pounding with local tools, roasting, and using red pepper or wood ash help preserve food.

Common traditional methods include sun drying and fermentation. Fermentation creates acids that stop harmful organisms from growing, preventing spoilage. This method has been used for generations to preserve vegetables like cassava and sweet potatoes. In Sudan, meat from animals is salted, dried, and stored as "shermout."

In Italy, people use methods like drying, fermentation, and adding salt to preserve food. For example, fruits are dried for later use, and families make tomato sauce to store for colder months.

Educating people about food waste is an effective way to reduce waste at home. A study in primary schools showed that teaching children about food waste changed their behavior. Before the program, some students threw away snacks they did not finish. After learning about food waste, they ate all their snacks or took leftovers home. The program taught students about portion sizes, managing leftovers, and the environmental impact of waste.

Collection

In places where waste collection is managed by the government, food waste is often handled by the same organization that collects other types of waste. Most food waste is mixed with general waste at the location where it is created. Separating food waste from other waste at the source, called source-separated organics, allows for special disposal methods that are not used for other types of waste. In the United States, businesses often find better ways to use large amounts of food and drink waste.

From the late 1800s to the middle of the 1900s, many cities collected food waste (called "garbage" at the time, rather than "trash") separately. This waste was often cleaned using steam and given to pigs, either on private farms or in public pig farms.

Some areas are now restarting separate curbside collection of food waste. To reduce costs and increase the amount of food waste separated, some local governments, especially in Europe, have started collecting biodegradable waste (such as garden waste) every other week. This method allows for more recyclable materials to be collected at a lower cost and improves collection rates. However, this system means waste is collected every two weeks, which can cause problems. During hot weather, food waste can rot, create bad smells, and attract animals. Proper waste container design is important to make these systems work effectively.

In the United States, curbside collection of food waste is also practiced, sometimes by combining food scraps with yard waste. Some states have banned certain types of yard waste, like leaves, branches, and trimmings, from landfills. When food scraps and yard waste are collected together, they are often recycled and turned into compost for reuse.

Disposal

Food waste can be handled in ways other than throwing it in landfills. It can be composted to make soil and fertilizer, used as animal feed, or turned into energy or fuel. Some parts of fruits and vegetables can be processed to create useful materials for industries, such as extracting succinic acid from orange peels or lycopene from tomato peels.

Putting food waste in landfills causes problems. As it breaks down, it creates bad smells, attracts insects and animals, and increases the amount of oxygen needed in the water that leaks from landfills. Rules in the European Union and other countries require reducing organic waste sent to landfills for these reasons. Starting in 2015, New York City banned restaurants from sending organic waste to landfills.

In the United States and the United Kingdom, about 19% of landfill waste is food scraps. These items break down easily and produce methane, a strong greenhouse gas. Methane is the second most common greenhouse gas in the air, also made by landfills in the U.S. Although methane stays in the atmosphere for only 12 years, it traps heat much more effectively than carbon dioxide. Humans are responsible for over 60% of methane emissions worldwide.

Large amounts of fish, meat, dairy, and grain are thrown away globally, even though they could be used for other purposes. Historically, feeding food scraps to animals like pigs and chickens has been a common way to handle household waste. These animals use about two-thirds of their food as gas or waste, while the remaining third becomes meat or dairy products. Other methods of farming and feeding animals could help reduce waste.

Bread and other grain-based foods thrown away could be used to feed chickens. Chickens are often given mixtures of waste grains and byproducts in a mix called chicken scratch. Some people who raise chickens at home say feeding them table scraps is part of a sustainable lifestyle, though not all recommend it. Ruminants and pigs have also been fed bakery waste for many years.

Some food waste, like meat, can be used in maggot farming. These maggots can then be fed to other animals. In China, some food waste is used to feed cockroaches.

Composting is a way to break down food waste and reuse it as fertilizer. Composting uses bacteria to turn food waste into simpler materials that improve soil. This process helps reduce water runoff and soil erosion by improving how water soaks into the ground. Studies show composting can reduce the loss of soil, nutrients, and pesticides to streams by 75–95%.

Composting food waste reduces greenhouse gas emissions. In landfills, food waste breaks down without oxygen, creating methane that enters the air. When composted, food waste breaks down with oxygen and produces compost instead of methane. New York City now requires restaurants and food companies to compost their leftovers. A company in Wisconsin called WasteCap helps communities create composting plans.

Municipal Food Waste (MFW) can be composted to make fertilizer. Many cities choose this method because it protects the environment and saves money. Landfills require space and money to operate, and some areas, like San Francisco, require residents to separate compost from trash. Fines are given for not following the rules: $100 for homes and $500 for businesses. The city says this helps businesses save up to $30,000 a year on waste disposal costs.

Europe has many composting plants, with about 2,000 total. Italy has 240 working plants and collected about 6.1 million tons of food and garden waste in 2015, or 100 kg per person each year. Italy is a leader in composting in Europe, with 35 million residents involved in collecting biowaste.

Composting is a simple and eco-friendly way for homeowners to reduce landfill waste. Instead of letting food scraps rot in trash cans, they can be composted outside using worms and added to gardens.

Composting can spread through communities if enough people adopt the practice. A 2018 study found that 25% of a population can influence others to change habits, even if they are in the minority.

Anaerobic digestion breaks down waste without oxygen, creating useful gases and a fibrous material. These plants use methane from waste to generate electricity, reducing costs and emissions. The U.S. Environmental Protection Agency says this process keeps food waste out of landfills. Instead of releasing methane into the air, it is captured and reused.

Because composting produces large amounts of biogas, safety measures are needed to prevent explosions or poisoning. Proper maintenance and protective equipment are required. Some U.S. states, like Oregon, require permits for these facilities due to risks to people and the environment.

Food waste from garbage disposals goes into sewers and is treated with other sewage, creating sludge. In commercial kitchens, waste from sinks, dishwashers, and drains is stored in tanks called grease interceptors to reduce sewer flow. This waste, called fats, oils, and grease (FOG), is a major problem in the U.S. due to aging sewer systems. The U.S. EPA says improper FOG disposal causes sewer overflows, releasing 3–10 billion gallons of untreated wastewater yearly into waterways. This leads to about 5,500 illnesses annually from exposure to contaminated water.