What Counts as Food Waste? The required, the unavoidable and the avoidable

Open the fridge. There is a bag of spinach turning into liquid, half a container of rice from the weekend and a lemon that has gone hard in the door. You did not plan any of that. It just happened, the way it happens in most kitchens, a little at a time until the bin fills up.

Food waste has a guilt problem. The word seems like an accusation so most people either tune it out or feel bad and change nothing. But both reactions miss the fact that a large share of what ends up in the bin was never yours to save, and the share that was follows a small number of predictable patterns. Once you can tell those two apart, the problem stops being a moral one and starts being something you can work with.

Food waste and food loss are not the same thing

The terms get used interchangeably, and the difference matters because it tells you which problems are yours to influence.

Food loss happens before food reaches you. It's the produce that spoils in transit, in storage, in the field, anywhere from the farm before it gets to the shop and to you. The FAO tracks this as loss from the farm up to, but not including, the retail shelf.

Food waste happens at the other end of the chain; in shops, restaurants and homes. Globally it's the larger consumer-facing side. The UN Environment Programme's Food Waste Index found the world threw out 1.05 billion tonnes of food in 2022, and households were responsible for 60% of it. That's more than food service and retail combined. That last figure is the one worth sitting with. The biggest single source of food waste on the planet is not a factory or a supermarket. It is the kitchen.

So what truly counts as food waste?

Food waste is food meant for people that gets thrown away instead of eaten. In your home, that covers cooked food nobody finished, produce that spoiled before you got to it and packaged food that timed out in the cupboard.

The reason the word feels slippery is that big institutions measure it more broadly than you experience it. To track national progress toward the Sustainable Development Goals, agencies often count the whole weight of what leaves the kitchen, peels and bones included. That makes sense for policy. But it's less useful when you are standing over the bin trying to work out what you could have done differently.

The three kinds of food waste, sorted by the question "could I have eaten it?"

The most useful framework here comes from WRAP, the organisation behind much of the global food waste measurement, and it sorts food waste by the question, was this ever edible?

1. Avoidable waste

Avoidable food waste is food that was edible at some point before you binned it. The slice of bread, the apple, the leftover stew, the yogurt one day past the best-before date, etc. In Canada, it's 63% of what households throw away, roughly 2.3 million tonnes of edible food a year nationally, at a cost of more than $1,300 for the average household. This is the category that's preventable in principle.

2. Possibly avoidable waste

Possibly avoidable waste is a grey zone. Food some people eat and others don't, or it's edible depending on how you prepare it. Bread crusts, potato skins, bones, apple peel, broccoli stalks. None of it is wrong to compost, and none of it is a failure to throw out. It's simply where habit, knowledge, preference and culture decide the outcome. This makes it the category most responsive to a small change in how you cook. Imagine cooking your potatoes with the peel instead of always peeling.

3. Unavoidable waste

Unavoidable waste is the part that was never edible in normal circumstances. Eggshells, orange peels, tea bags, coffee grounds, the tough ends of some foods, etc. Love Food Hate Waste Canada names these as the food that cannot generally be eaten or sold. Throwing out avocado peels is not food waste in the sense that should trouble you. It's the ordinary residue of cooking and no amount of planning removes it.

A lot of people lump the eggshells in with the forgotten spinach and feel vaguely bad about the whole bin. Separate them. You're only really trying to move the avoidable pile.

Where avoidable waste usually happens in home kitchens

Avoidable waste usually builds up at a handful of specific moments as food moves through your week. Here are 7 of such points

1. The shop. Bringing home more than the week can absorb, often because the bigger pack looked like better value.
2. The fridge. Storing food in the wrong spot or the wrong way and so it spoils faster than it should.
3. The forgotten stock. Something goes to the back of the pantry or freezer and is out of sight until it's out of date.
4. The pot. Cooking more than gets eaten, and the extra is never reused or stored well.
5. The plate. Portions are bigger than appetites, and what's left is scraped into the bin.
6. The date label. A "best before" date gets read as a safety deadline, and perfectly good food is tossed on the day.
7. The cutting board. More gets trimmed away than needs to be and edible parts go with the scraps.

Each one is a point in a routine, which means each one has a specific fix to do better.

What to do about each source of avoidable food waste

For the shop, buy for the week you will have. Check the fridge and pantry before you leave, and treat a large pack as good value only if you have a plan for it. In Canada, vegetables and fruit are the most wasted foods by weight, at 30% and 15% of the household total, so the produce aisle is where restraint pays off most.

For the fridge, learn where things last better. Most produce keeps longer in the crisper than in the door and leafy greens revive in cold water. Keep perishables where you can see them.

For the forgotten stock, put older items in front and newer ones behind, in the pantry and the freezer. And you can take a quick weekly look at what needs using first to make a meal plan.

For the pot, cook to the number of people eating, and decide before you cook what happens to any extra. Leftovers only prevent waste if you intend to use them later. So plan accordingly and store the leftover well.

For the plate, serve smaller portions and go back for more if needed. It's a small change with a rather big effect because food not served is food not scraped away, and money not wasted.

For the date label, here are two date labels; best before and expiry. "Best before" is about quality, not safety, so many foods are fine to eat and sell after that date if they've been stored properly. "Use by" or "expiry" is the one to consider especially for critical foods like baby formula and dietary supplements. Confusing the two sends a lot of edible food to the bin on a date that only ever "slightly less fresh."

For the cutting board, trim less and if possible more carefully to ensure only the ynavoiable goes into the bin.

Why the avoidable pile is worth the effort

The case for bothering about food waste isn't only environmental, though that part is critical. The more immediate case is that this is money you already spent as well as the energy and time spent shopping or cooking. And unlike food loss on farms or in supply chains, this situation sits right inside most people's week.

Some of the food waste that makes people feel bad was not savable to begin with. And most of what's worth saving comes down to a few ordinary moments between the shop and the plate. You don't have to fix all of it, and certainly not at once. You just have to know which pile is which, and send your attention where it can make a difference.