Food loss and waste refers to food that is thrown away or not eaten. This happens at many stages in the food system, including during farming, processing, transportation, selling, and eating. Globally, about one-third of all food is wasted. This waste uses a lot of resources used to grow food. A 2021 study by the United Nations Environment Programme found that about 931 million tonnes of food are wasted each year, or about 121 kilograms per person. This waste comes from three main areas: 61% from homes, 26% from restaurants and food service businesses, and 13% from stores.

Food waste can be reduced by preventing it (such as through better food storage), reusing food (like donating it to those in need), using it for animal feed, or recycling it. Putting food in landfills should be avoided because it creates a large amount of the greenhouse gas methane. Reducing food waste at all stages of the food system helps lower the environmental effects of farming by using less water, land, and other resources.

Wasted food plays a major role in agriculture’s impact on climate change. It causes about 3.3 billion tons of greenhouse gas emissions each year. It also affects other environmental issues, such as using too much land and water and harming wildlife. Wasted food also makes it harder for people in some parts of the world to get enough food. The United Nations’ Sustainable Development Goals aim to cut global food waste in half by 2030, focusing on reducing waste at stores and by consumers, as well as reducing food loss during farming and transportation. In 2022, nations at the United Nations Biodiversity Conference agreed to reduce food waste by 50% by 2030.

Definition

Food loss and waste happen at every stage of the food supply chain, including production, processing, sales, and consumption. Definitions of food loss and food waste, as well as what parts of food are considered lost or wasted, can vary depending on the situation. Different organizations, such as international groups, government agencies, and professional bodies, 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 this definition, food loss occurs from the time food is harvested, slaughtered, or caught up to, but not including, the point when it is sold. Food waste happens at the retail and consumption levels.

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

Under Sustainable Development Goal 12, the FAO is responsible for measuring 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, partially processed, or unprocessed, intended to be, or reasonably expected to be ingested by humans" (including drinks and chewing gum) but excluding items like animal feed, medicine, cosmetics, tobacco, and narcotics. This definition was updated in 2018 to combine previous definitions after changes to how waste and food were legally described.

In the United States, the Environmental Protection Agency (EPA) uses three categories:
– Excess food: Food that is donated 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 farms, such as crops not harvested.

In 2006, the EPA defined food waste as uneaten food and food scraps from homes, stores, restaurants, and workplaces. States in the U.S. may define food waste differently, but many had not done so as of 2009.

A 2019 FAO report noted that food loss and waste are often measured in physical units, like tonnes, which can overemphasize the weight of low-value items. To address this, the report used a method that considers the economic value of food.

Research by Hall et al. (2009) estimated that food waste in the U.S. increased from about 30% of the food supply in 1974 to nearly 40% in the early 2000s, or about 900 kcal per person per day in 1974 to 1400 kcal per person per day in 2003. A 2012 report by the Natural Resources Defense Council stated that Americans waste up to 40% of safe-to-eat food. Buzby & Hyman (2012) estimated that food loss in the U.S. costs about 10% of the average food spending per person in 2008.

Another way to measure food waste is through "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 livestock human-edible food results in a significant net loss of calories. For example, if the U.S. used all human-edible food for human consumption instead of feeding it to animals, it could provide enough food for an additional 350 million people. Globally, livestock consume about 1738 kcal of human-edible food per person per day but return only 594 kcal in animal products, resulting in 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 retail stores. Losses are often higher for fruits and vegetables than for cereals and pulses. However, significant losses also occur in sub-Saharan Africa and Eastern and South-Eastern Asia for cereals and pulses, while losses are lower in Central and Southern Asia.

UNEP’s Food Waste Index estimates that in 2019, about 931 million tonnes of food, or 17% of 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, nearly double 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 people is lost or wasted globally, totaling about 1.3 billion tonnes per year. In developing countries, food loss occurs mostly during post-harvest and processing stages, while in developed countries, most waste happens at retail and consumer levels. Food waste by consumers in industrialized nations (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% of all food produced globally, or 1.2–2 billion tonnes, is not eaten.

In New South Wales, Australia, charity OzHarvest delivers over 25 million meals annually using food that would otherwise be wasted. Australia loses $20 billion yearly due to food waste, which harms the environment by wasting resources used to grow, package, and transport food. Composting and worm farming by households divert over 361,000 tonnes of food waste from landfills each year. Over 45% of Australians grow some of their own food, with 52% of households growing food and 13% planning to start. However, yields are often low, and many people stop growing food after a short time. Reasons for growing food include health benefits, better taste, and saving money.

Food waste in landfills is estimated to produce 7.6 million tonnes of CO₂ annually, costing households $19.3 billion. It also causes bad smells, pollution, and risks to public health. In March 2019, Australia’s environment ministry shared findings from its National Food Waste Baseline, which will help track progress toward reducing food waste by half by 2030.

The Australian government has taken steps to reduce 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 food storage workshops, composting education, and food donation initiatives. Studies show people are more likely to reduce waste for financial reasons than for altruistic ones, with households motivated by saving money wasting $100 less annually.

Coal mining and gas drilling in Australia pollute water sources, harming agriculture and ecosystems. These industries release contaminated water into rivers, and no clear solutions exist for managing waste from gas extraction. Long-term 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% want less strict standards for food appearance. Despite this, 81% believe individuals must also take responsibility for reducing waste.

In Canada, 58% of food is wasted annually, totaling 35.5 million tonnes, worth $21 billion. This amount could feed all Canadians for five months. About one-third of this waste could be redirected to those in need. Factors contributing to waste include buying too much food, poor packaging, and improper disposal. The Canadian government identifies three main causes: overbuying, faulty packaging, and improper disposal.

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

Canada’s efforts to reduce waste include:
– Pledging to develop strategies in the Strategy on Short-lived Climate Pollutants to cut avoidable food waste, reducing methane emissions from landfills.
– Implementing a Food Policy for Canada to create a more sustainable food system.
– Hosting experts in 2019 to discuss ways to measure and reduce food waste across the supply chain.

During the 2022 Quebec general election, the Québec solidaire party promised to prioritize ending food waste if elected. The party plans to cut waste by 50% by requiring large businesses and institutions to donate unsold food to groups that distribute it or process it.

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” was launched to reduce waste, including encouraging restaurants to limit orders to one fewer main dish than the number of customers.

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

Impact

According to the United Nations, about one-third of all greenhouse gas emissions caused by humans are connected to food. Studies show that to reduce land use, the main focus should be on meat and animal products, which make up 60% of the land use linked to food waste. If the goal is to address water shortages, cereals and pulses contribute the most (more than 70%), followed by fruits and vegetables. For greenhouse gas emissions from food 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 because of differences in farming methods and crop production. According to the IPCC 6th Assessment Report, reducing food waste would help improve the availability of resources like water, land, and energy, while also lowering greenhouse gas emissions.

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 global food insecurity. For example, food loss in Africa is estimated to be twice the amount of calories needed to solve hunger, while the extra 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 on a plan to protect biodiversity. This plan includes a goal to cut food waste by 50% by 2030.

According to the Food and Agriculture Organization’s The State of Food and Agriculture 2019, reducing food loss and waste can lead to benefits that society gains, even if individuals may not notice them. These benefits include: (i) better productivity and economic growth; (ii) improved food security and nutrition; and (iii) reduced harm to the environment, such as lower greenhouse gas emissions and less pressure on land and water resources. The last two benefits are often seen as side effects of reducing food waste.

People at all levels of society have responded to food waste in different ways. These responses include campaigns by advisory and environmental groups, as well as media attention on the issue.

The food waste hierarchy suggests that preventing waste and reusing food for human consumption should be the top priorities. General strategies to reduce food waste include two main approaches: prevention and valorisation. Prevention involves actions that reduce food production and stop food from being made unnecessarily, such as donating food or reprocessing it into new products. Valorisation includes actions that recover materials, nutrients, or energy from food waste, such as using it for animal feed, fuel, or energy.

Many studies have shown the environmental benefits of food waste prevention. Examples include donating food, reusing unharvested vegetables in food production, reprocessing surplus bread into beer, and making chutney or juice from leftovers. Food waste can also be used to create valuable products, like a fish oil substitute from marine microalgae, without affecting energy production through biogas. Most studies agree that reducing food waste through prevention or valorisation for human use provides greater environmental benefits than lower-priority methods, such as energy production or disposal.

Several initiatives help rescue food that would otherwise go uneaten. This food can come from supermarkets, restaurants, or private homes. Examples of these initiatives include:
– Food banks,
– Online platforms like Too Good To Go and Olio,
– Public foodsharing shelves, such as those from foodsharing.de, and
– Dumpster diving.

One way to address food waste is to stop it from being created in the first place. Consumers can reduce spoilage by planning their food shopping, 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. Through advertisements, information on food storage and preparation, and in-store education, the UK saw a 21% drop in avoidable household food waste over five years.

Another solution is "smart packaging," which can more accurately show when food is spoiled than current 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, an initiative called Cambio Verde allows farmers to give surplus produce to people who bring glass and metal for recycling. This encourages waste reduction. In Europe, the Food Surplus Entrepreneurs Network (FSE Network) connects social businesses and nonprofit groups to share best practices for using surplus food and reducing waste.

Most experts agree that reducing food waste has major environmental benefits. However, some studies suggest that saving money from preventing food waste might lead to increased consumption, which could reduce some of the environmental benefits.

For many cultures, food preservation techniques have been used for centuries to reduce waste and ensure survival. Today, overproduction of food has led to large amounts of waste. Recognizing and using these traditional methods can help reduce household waste.

In Africa, food loss is a major problem, often caused by poor preservation practices. For example, in sub-Saharan Africa, more than 40% of food is lost after harvest and during processing. Research shows that using African indigenous knowledge, such as traditional methods for processing, preserving, and storing food, can improve food security. In Nigeria, techniques like sun drying, pounding with locally made tools, roasting, and using red pepper or wood ash are common.

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

In Italy, traditional methods like drying, fermentation, and adding salt are used to preserve food. For example, fruits are dried for use out of season, and families make tomato sauce yearly to store for colder months.

Education and awareness are effective ways to reduce food waste in households. A study at primary schools showed that teaching students about food waste changed their behavior. Before the program, some students threw away snacks when they had too much. After the program, students either ate all their snacks or saved leftovers. The program increased awareness of portion sizes, leftover management, and the environmental impact of waste. Activities included classroom lessons and discussions.

Collection

In places where waste collection is handled by the government, food waste is often managed by the same organization responsible for collecting other types of waste. Most food waste is mixed with general waste at the source. Separating food waste from other waste, called source-separated organics, allows it to be handled in ways that are not possible for other types of waste. In the United States, companies often find more useful ways to use large amounts of food and drink waste from businesses.

From the late 1800s to the middle of the 1900s, many cities collected food waste separately. This waste, called "garbage" instead of "trash," was usually cleaned by steaming and given to pigs on farms or in city-owned pig farms.

Now, some areas are starting to collect food waste separately again. To lower costs and increase how much food waste is separated, some European cities have begun collecting biodegradable waste (such as garden waste) every other week. This method allows more recyclable materials to be collected at a reasonable cost and improves collection rates. However, this system means it takes two weeks before the waste is picked up. A problem with this method is that during hot weather, food waste can rot, smell, and attract animals. Properly designed waste containers are important to make this system work. In the United States, food scraps and yard waste are sometimes collected together. Some states in the U.S. have banned putting leaves, branches, and trimmings in landfills. When food scraps and yard waste are collected together, they are recycled and turned into compost for reuse.

Disposal

Food waste can be handled in ways other than sending it to 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 also be processed to create useful materials for industries, such as 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 pests like flies and rats, and increases the amount of oxygen needed in the water that leaks from landfills (called leachate). Rules in places like the European Union and New York City require reducing organic waste in landfills for these reasons. Starting in 2015, New York City banned restaurants from throwing organic waste into landfills.

In the United States and the United Kingdom, about 19% of landfill waste is food scraps. These scraps break down easily and create methane, a strong greenhouse gas. Methane is the second most common greenhouse gas released into the air. 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 food, such as fish, meat, dairy, and grain, are wasted globally. These items could be used to feed animals instead of being thrown away. Historically, people have fed food scraps to animals like pigs and chickens. These animals use about two-thirds of their food as waste, and the remaining third becomes meat or dairy. Other farming methods could also reduce waste.

Bread and other cereal products thrown away could be used to feed chickens. Chickens are often given mixtures of leftover grains and byproducts, called chicken scratch. Some people who raise chickens at home believe feeding them food scraps helps the environment, though not all experts agree. Similarly, fish and meat waste have been used to feed animals like pigs for many years.

Certain food waste, like meat, can be used in maggot farming. The maggots can then be fed to other animals. In China, some food waste is processed by feeding it to cockroaches.

Composting is a way to break down food waste using microorganisms. This process turns food scraps into nutrient-rich soil. Compost helps reduce water runoff and soil erosion by improving how water soaks into the ground. Studies show compost can reduce the loss of soil, nutrients, and pesticides into streams by up to 95%.

Composting food waste reduces greenhouse gas emissions. In landfills, food waste breaks down without oxygen, creating methane gas. 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 also 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. Sending waste to landfills is costly and uses limited space. In San Francisco, citizens are required to separate compost from trash, with fines for not following the rules. The city says composting can save businesses up to $30,000 yearly on garbage costs.

Europe has many composting plants, with Italy having 240 operating facilities. In 2015, Italian cities collected about 6.1 million tons of food and garden waste, averaging 100 kg per person per year. Italy is a leader in composting in Europe, with about 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 outdoors with worms and used in gardens.

Composting can spread through communities, as people learn from others. A 2018 study found that if 25% of a population adopts a new habit, it can influence the majority to follow.

Anaerobic digestion is a process that produces gas and a fibrous material. This method uses methane from food waste to generate electricity, reducing costs and greenhouse gases. The U.S. Environmental Protection Agency says this process keeps food waste out of landfills.

Composting can create large amounts of biogas, which may cause safety risks like explosions. Proper maintenance and protective equipment are needed. Some U.S. states, like Oregon, require permits for these facilities to protect public safety.

Food waste from garbage disposals goes into sewers with other sewage, creating sludge. In commercial kitchens, waste from sinks and dishwashers is collected in tanks called grease interceptors to reduce sewer overflow. This waste, called fats, oils, and grease (FOG), is a major problem in the U.S. because it clogs aging sewer systems. The U.S. Environmental Protection Agency says improper FOG disposal causes overflows that release 3–10 billion gallons of untreated wastewater into waterways each year, leading to up to 5,500 illnesses annually.