Everything you need to know about food waste

Food waste is a climate problem any person can take part in solving


Doing something about the climate crisis can feel overwhelming, especially for an ordinary person. Luckily, there’s something that we all can do to make a real difference: waste less food. In fact, chucking less grub comes in a close second in terms of environmental impact (just behind switching to a plant-based diet), according to analysis from Project Drawdown.1 And we have a lot of room for improvement: At least one-third of the world’s food is lost to waste. That’s more than one billion tons of potential edibles a year worth about $1 trillion.2 In the U.S., the biggest chunk of that waste happens in our own homes.

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The cycle of overproduction, overconsumption, and imperfect waste management practices can be complex. What we do know is that the mountains of grub we toss every year add up to major greenhouse gas emissions and entire economies’ worth of misspent resources. But food waste is unique as a climate problem in that its solution is about as straightforward as they come: chuck less food. This group of cheat sheets are designed to help you do just that. They include the scoop on what exactly counts as food waste, where it comes from, and, most importantly, what you (yes, you!) can do about it. 

What is food waste?

Food waste is simply that: grub that’s produced but that doesn’t get eaten. The exact definition, though, can vary a bit based on the context. For some experts and estimates, food waste includes crops left behind on the field, leftover scraps on plates in restaurants, stems and seeds from cooking that usually end up in the trash, and, of course, grub that just goes bad. Some analysts term food that isn’t quite food yet—say, crops or scraps lost at the production level—as food loss. Either way, the vittles themselves aren’t the only thing that gets flushed when a bag of spinach hits the bin: Resources like water, fertilizer, land, and fuel all end up wasted when food doesn’t end up feeding anyone.  

Wasted food causes a hoard of problems for the environment. Food waste, more often than not, piles up in the landfill, where it rots in an anaerobic (that’s low-oxygen) environment and creates methane. The amount of this potent greenhouse gas that comes from rotting grub adds up to 3.3 gigatons, according to the United Nations Food and Agriculture Organization.3 If food waste were a country, it would be the third-largest emitter in the world. Meanwhile, the resources that go into making all this excess generate emissions, destroy habitats, and heighten pollution risks from herbicides and pesticides. All the while, billions of people across the world experience food insecurity—a lack of regular access to safe, healthy meals. 


FAQ: How much energy goes into making food that is eventually wasted?

When you include the entire production cycle—from tractors that till soil to trucks that haul around produce—38% of the total energy used in worldwide food systems goes towards making grub that’s ultimately wasted or lost. 

How much food do we waste in the U.S. and beyond?

Americans by far have the largest per-capita food waste footprint in the world: more than 350 pounds annually, which equates to around 1,250 calories per person every single day. 45 Most of that food waste happens at the household level—so after the vittles have been farmed, harvested, transported, packaged, and (sometimes) prepared. Taken together with excesses in production, food service, and retail, high-side estimates find that America wastes at close to 40% of the food we create.6

Though the U.S. is the per-person champ of food waste, it’s not alone in this dilemma. The most household food waste in the world in terms of sheer tonnage occurs in China (91 million metric tons), India (68 million metric tons), Nigeria (38 million metric tons), Indonesia (21 million metric tons), and then the United States (19 million metric tons), according to the U.N.7 


FAQ: How much water is used for wasted food in the U.S.?

Trashed food uses up about 5.9 trillion gallons of clean water. That’s the equivalent of the annual usage of 50 million American households.

Where does food waste come from?

The vast majority of food waste in America comes from our own homes, especially high income and small households. According to ReFED, a nonprofit focused on food-waste solutions, U.S. homes tossed about 43 million tons of food in 2022. But waste can be found at any point from farm to bin: That same year, U.S. farms created 15 million tons of food waste, grocery stores and supermarkets chucked just under 5 million tons, and restaurants and food service providers wasted around 13 million tons each.8 


FAQ: What foods get wasted the most often?

Produce is the most likely food group to end up in the bin in the United States, followed by prepared foods and animal products like dairy and eggs. Fresh fruits and veggies make up about 33% of all tossed food in the U.S.

How to reduce food waste in your home

Food waste ending up in the landfill is the worst-case scenario, but there’s a lot that can be done before last week’s lasagna makes its way to the dump. We can shop smarter, cook more creatively, and store our leftovers and groceries for maximum longevity. Sharpening our understanding of those seemingly arbitrary “best buy” dates can’t hurt, either. Additionally, donating food that you know your household won’t want can help reduce waste and support those in need. 

Beyond eating food that could potentially go to waste, one of the most important management techniques is one that you’ve likely already heard of: composting. Composting food waste is essentially a sped-up version of what happens in nature when organic matter gets broken down by other organisms. Composting can go down at an industrial scale, where waste is gathered up and taken to a plant, but it can work in a closely-monitored spot in your backyard. 

Still, there are some things that consumers can’t fix on their own, which is where regulations and laws come into play. Some countries, notably South Korea, have food waste laws that make sure 95% of edible castoffs get recycled. In the U.S., however, government oversight is piecemeal. While the federal government has taken steps to help make food donation easier, much of the work is happening locally. Several states and cities—including Connecticut and California—have set up reduction requirements for heavy wasters in recent years.


FAQ: How much landfill waste is just old food?

Food makes up around 24% of solid waste in U.S. municipal landfills—and it’s the category that takes up the most space in those massive trash heaps.

What are some larger-scale food waste solutions?

Beyond composting, food waste can have several second lives. One of these is creating biogas, or energy, via anaerobic digesters. This process puts waste in a warm, oxygen-free environment with microorganisms to produce what’s essentially natural gas or methane. This potent greenhouse gas can then be put to use powering homes or facilities instead of letting it leak out into the atmosphere as it would in a landfill. In 2019, anaerobic digesters processed more than 17 million tons of food waste in the U.S.9

Food waste can also become food—for animals. Currently, 6% of all crop emissions come from goods grown for animal feed.10 Repurposing leftovers cuts down on the need for growing those  crops and provides an option for farms and communities trying to get rid of food waste. 


FAQ: Where is community composting available in the U.S.?

Between 2014 and 2019, the number of communities with composting programs grew by 65%. More than 200 cities around the country offer curbside food scrap collection for composting. 

  1. The powerful role of household actions in solving climate change, Project Drawdown, October 2021. ↩︎
  2. UNEP Food Waste Index Report 2024, United Nations Environment Programme, Mar. 2024. ↩︎
  3. Food wastage footprint: Impacts on natural resources, Food and Agriculture Organization, 2013. ↩︎
  4. UNEP Food Waste Index Report 2024, United Nations Environment Programme, Mar. 2024. ↩︎
  5. The estimated amount, value, and calories of postharvest food losses at the retail and consumer levels in the United States, US Department of Agriculture, Feb. 2014. ↩︎
  6. ReFED Insights Engine, 2023 ↩︎
  7. UNEP food waste index report 2021, United Nations Environment Programme, March 2021. ↩︎
  8. ReFED Insights Engine, 2023 ↩︎
  9. Anaerobic digestion facilities processing food waste in the United States
    , US Environmental Protection Agency, April 2023. ↩︎
  10. Reducing food’s environmental impacts through producers and consumers, Science, June 2018. ↩︎