The Beginner’s Guide to Reducing Food Waste

6 ways to help the environment using your own fridge.

June 6, 2022

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Illustration of a trash can atop a stove

Illustrations by Michele McCammon

Imagine a farm the size of California and Alabama combined. In one year, such a farm would use trillions of gallons of water and release the same amount of greenhouse gases as 58 million cars would in the same period. But then, imagine that after all the food—a total of 80 million tons—is harvested and loaded onto trucks, instead of it ending up on our plates, the trucks take it straight to the landfill. That’s essentially the state of food waste in the United States today.

This imaginary farm is one analogy used by Dana Gunders, author of Waste Free Kitchen Handbook and executive director of ReFED, a nonprofit that aims to end food waste across the United States. Since stumbling upon the scale of the problem while working on sustainable agriculture, Gunders, ’00, MS ’02, has become an anti-waste advocate. While individuals may not have much control over the 60 percent of U.S. food waste that occurs in commercial food production, we can address the remaining 40 percent: what we discard in our own homes. Whether you too often find your fridge stuffed with leftovers or just want to know what to do with that little bit of leftover coconut oil (think hair conditioner), Gunders offers five steps to help you start trimming the fat from your food waste.

Make an ingredients plan.

“A lot of times when we go shopping, we’re very aspirational,” Gunders says. You probably know what she’s talking about: those times when you tell yourself that this is the week you start eating more fruits and vegetables or try new adventurous ingredients, so you fill your cart accordingly. But then the week passes and you don’t follow through, while the food you bought sits moldering in the back of your fridge. These impulse buys, Gunders says, are why it’s important to create a list and stick to it when you’re at the store.

Realistic planning about what you will be able to use and consume in a given amount of time, Gunders says, is the No. 1 thing you can do to reduce food waste. You don’t need to spend hours each weekend flipping through cookbooks to pick precise recipes for each meal. Instead, choose building blocks. Pick out two proteins, one or two carbs, and a few vegetables that you can make in advance and then incorporate into your meals throughout the next few days. In her book, Gunders suggests a sauté of broccoli and peppers—it can be a side to your enchiladas on one night and then incorporated into a soup or meatloaf later in the week.

Illustration of a banana bunch

Store food strategically.

Once the groceries have made it back to your home, appropriate and effective storage ensures that the food will last as long as possible. Online resources like can help you figure out how best to store each item and how to properly utilize your refrigerator. You can learn when to use bags, what the ideal storage temperature might be and what those little dials on the crisper drawers are really for (answer: to adjust the humidity—high for leafy greens prone to wilting and low for fruits, which otherwise might overripen quickly). All this will help buy you time to incorporate items into your meals before they go bad. Or after: Sour milk, for example, can be used in pancakes and more. Overripe avocados can be turned into chocolate mousse.

In general, you’ll keep refrigerated foods fresh longer if you put meats toward the bottom (where the shelves are colder) and leftovers, drinks and yogurts toward the top. And don’t overstuff the fridge: Cold air needs to circulate in there for optimal functioning, and some “white space” gives you a better chance of seeing everything you’ve got.

Illustration of a milk carton and glass full of milk

Let go of labels.

Use by. Best before. Sell by. Expiration date. Better if used by. What do all these designations mean? The answer is: not much. Those labels, it turns out, aren’t federally regulated. Nominally, they’re to tell consumers when the product is at its peak quality or freshness. In practice, most food is safe to consume for some time after the printed date. Use your own judgment (and senses of smell, taste and sight) about whether something is still good to eat or needs to be tossed.

One caveat. For “the foods that they tell pregnant women to avoid—so things like ready-to-eat sandwiches, deli meats,” Gunders says, “you should probably listen to the date.”

Illustration of an apple with snowflakes

Freeze—but briefly.

Many people think of the freezer as a place for long-term storage. But a better use for your freezer, Gunders says, is short-term storage. “The freezer is like a magic pause button on food,” she says. What that means is those leftovers you know you’re going to get sick of can be tucked in the freezer for a week or two before you revisit them. This way, you keep variety in your diet and don’t feel pressured to get through leftovers or perishables.

More things can be frozen than you think: sliced bread and shredded cheese are two examples, but so are coffee beans and fresh herbs and spices in oil. In general, Gunders says, the key to freezing is thinking ahead to how you want to use the food or ingredient when you take it out, then freezing it in correspondingly sized portions.

Illustration of a fridge in a shopping cart

Eat down what you have.

Try to use up whatever you’ve already bought. That means shopping your fridge before going to the store again. You might designate a day in your grocery cycle as a sort of hodgepodge meal day, where you add remaining ingredients to a stir-fry or taco medley. Maybe even come up with a name for it—Waste-Less Wednesdays, anyone?

Illustration of eggs and egg shells with flowers growing out of the shells

Level up.

Even if you feel you’ve mastered the basics, some amount of food waste is inevitable; there are eggshells (great for the garden), citrus peels (add to vinegar for a DIY cleaner) and the occasional rancid oil (which you can use to polish wood). Some extra veggies can be given to pets. (Always verify that foods are safe and healthy for the specific animal you’re feeding.) Then there are the more creative salvages: Gunders says you can polish shoes with a banana peel and use coffee grinds in a facial scrub. And of course, there’s always the option of using nature’s wonders to help you break down your scraps through composting.

Evan Peng, ’22, is an editorial intern at STANFORD. Email him at

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