Around one-third of all food the world produces never gets eaten — at least according to the long-accepted estimate. But the problem is likely much bigger than this. More recent data suggests up to 40% of food is lost or wasted along the value chain, exposing a major blind spot in global food systems.

The consequences of this food waste, even at the lower end of the estimates, are huge. It means that an amount of land larger than China is used every year to produce food that no one will eat — especially egregious in a world where nearly 1 in 3 people face some level of food insecurity. About 45 trillion gallons of water, almost one-quarter of all water used in agriculture, is consumed in the process. And food waste is linked to about 8%-10% of the greenhouse gas emissions warming the planet.

The UN has set a goal to halve food loss and waste globally by 2030. But countries and companies can't begin to tackle the issue unless they know how much food is really lost or wasted — and where and why.

Why is it so hard to measure food loss and waste?

Today, we have only a rough idea of how much food is lost or wasted around the world. The widely used 'one-third' statistic is based on data from the Food and Agriculture Organization (FAO) and United Nations Environment Programme (UNEP), but it is only an estimate. This figure doesn't include food that is lost before it leaves the farm, such as crops that aren't fully harvested or spoil in storage.

More recent data from Tesco and the World Wildlife Fund (WWF) suggests that about 40% of the world's food supply goes to waste when on-farm losses are also considered.

But these numbers can only be so useful. Most are extrapolated from global data that isn't complete, relying on individual studies from various years to produce broad estimates. This can provide a general picture of food loss and waste within a region, but it is less helpful for pinpointing where exactly waste occurs and taking targeted action to reduce it.

In some cases, the data is also decades old; FAO's estimate is based on a 2011 study. Updated and more precise data just isn't available, as only 12% of the global population lives in countries currently tracking food loss and waste within their borders.

Accurately gauging how much food is lost or wasted involves measuring a lot of things across the supply chain — from how much fruit is left unharvested in the fields, to the vegetable scraps that a line cook throws out, to the questionable cheese in the back of your fridge. Almost no one is measuring on-farm food loss, in part because it can be difficult to determine the boundary between different causes, such as poor harvesting techniques or disease.

On top of that, many companies are still extremely reluctant to publish their food waste data due to possible reputational risks. Businesses may be worried about the public reaction and how their waste will compare with other companies. Or they may know they're wasting a lot and want to start improving before they publish any data.

On the other side of the supply chain, household waste is especially difficult to measure. People generally aren't very good at estimating how much food they throw out; one study found that almost half of Britons surveyed underestimated the economic cost of the food they wasted. In fact, most U.K. consumers say they don't waste food at all, but research by the Waste and Resources Action Programme (WRAP) shows that 70% of food waste in the U.K. comes from households.

The reality is that most people do waste food. It's not a problem limited to higher-income countries, either; research has shown food waste to be a growing issue in cities worldwide. And because organic waste isn't collected separately in most places, the only way to get accurate data on household food waste is to go through bins manually and analyze what is in them, an expensive and time-consuming process.

Major Companies Have Shown that Tracking and Reducing Food Waste Yields Big Benefits

So far, most progress on measuring and reducing food loss and waste has come from the private sector. Not only do big companies have the power to address waste up and down the supply chain, but they also have a financial incentive to do so. Research suggests that when food-related businesses such as restaurants and hotels invest in waste reduction programs, they can see up to a 14-fold return on their investment.

IKEA is a front-runner here. After pledging to halve food loss and waste by 2030, IKEA became the first global company to do so in all its restaurants in 2023 — reducing waste by 54%, years ahead of schedule. The company invested significant resources toward this goal, from hiring a dedicated team; to outfitting its restaurants with smart scales to measure food waste; to partnering with the Too Good to Go app, which allows customers to purchase discounted food that would otherwise be thrown out. But the payoff was big: In addition to saving more than 20 million meals and avoiding 36,000 tonnes of greenhouse gas emissions — equivalent to the emissions from more than 8,000 cars — every year, this shift is saving IKEA $37 million annually.

Meanwhile, Danone has reduced food waste in its global operations by nearly 20% compared to a 2020 baseline, and Danone North America has achieved a 30% reduction to date. One factor in Danone North America's success is its partnership with the Spoiler Alert sales platform, where foods close to expiration are matched with appropriate buyers. This has led to a 50% increase in the sell-through rate of its excess product. 

But examples like these are still few and far between. As of 2021, 28 of the world's 50 largest food companies were measuring their food loss and waste. And only 19 of these were publicly reporting on it. Moving forward, all major companies should start reporting food waste data from their operations, similar to how most now disclose their carbon emissions.

Governments need to play a bigger role to address waste on a global scale

While private sector progress is important, it's piecemeal by nature. Governments need to do more to promote tracking and reduction of food loss and waste across the entire value chain, from farms and factories to businesses and households.

Governments often struggle to understand what their role should be when it comes to reducing food waste. For example, should they focus on farmers or consumers, which require different approaches and different communications strategies? Which tactics will be most effective: requiring businesses to report on food loss and waste and work with their suppliers to reduce it? Incentivizing farmers to minimize losses in their fields? Or developing public behavior-change campaigns to slash waste in people's homes? Recent global events — including the COVID-19 pandemic and Russia's invasion of Ukraine — also made food loss and waste less of a priority issue for many governments as they focused on food security, price spikes and supply disruptions.

Still, some countries have made more progress than others on collecting national-level data and implementing solutions.

The U.K. has made great strides on measuring household food waste using periodic surveys and data from waste management authorities. It also developed the first-ever voluntary agreement with companies to address food loss and waste, known as the Courtauld Agreement. More than 300 food businesses have joined the effort, which is also helping farmers measure on-farm losses, promoting public behavior change and more. Recently, over 30 major companies have urged the U.K. government to go further and mandate reporting on food loss and waste.

In addition, all EU countries now measure food waste along supply chains (although not on farms) to some degree. And last year the European Commission proposed setting legally binding targets requiring EU member states to reduce food waste by 10% in processing and manufacturing and by 30% (per capita) jointly across restaurants, food service establishments and households by the end of 2030. The United States also recently announced a national strategy to reduce food loss and waste.

Other governments should follow these examples, using a combination of policy, education and financial levers to both mandate food waste tracking and support farmers, businesses and others in doing so. An immediate step countries can take is to incorporate food loss and waste reduction into their next national climate commitments (known as Nationally Determined Contributions), which are due in 2025.

Moving from measurement to action

Too often, it can be easy to get hung up on new "miracle" technologies for addressing food waste — such as smart fridges that can track expiration dates and suggest recipes based on the food you already have. But as useful as emerging technologies may be, they can also be a distraction from doing things that we already know work: processing and storing food properly, planning meals, freezing leftovers and donating to food banks.

The solutions are not rocket science; simple things like training employees with proper food handling skills or making small changes to the manufacturing process can have a huge impact. But they need much better communication up and down the chain. Right now, one end doesn't know what the other end is doing, which means solving a problem at one stage might result in worse problems elsewhere — like switching to a crop strain with higher yields that ends up being more susceptible to damage during transportation or storage.

Ultimately, the success of any strategy to reduce food waste will depend on accurate and timely data to reveal issues and inform solutions.

Through the Champions 12.3 coalition, WRI encourages a "target-measure-act" approach. The global target to cut food loss and waste in half has been set. Now, both countries and companies need to step up by connecting ambitious food loss and waste reduction targets to their climate strategies. If they haven't already, they must first quantify a base-year amount of food loss and waste inside their operations or borders and then begin monitoring change over time — and publicly reporting how much food they are wasting. It's the only way we can get to the next step: ramping up actions that save more food from garbage bins and landfills and put it into the hands of people who need it.

This article is also published in World Resources Institute. illuminem Voices is a democratic space presenting the thoughts and opinions of leading Sustainability & Energy writers, their opinions do not necessarily represent those of illuminem.