Food loss: the science and the societies — prevent, share, return

Talk of food loss usually starts with a single figure. According to an estimate published by the UN Food and Agriculture Organization (FAO) in 2011, roughly one-third of the food produced for human consumption — about 1.3 billion tonnes a year — is lost or wasted. This 'one-third' does not vanish all at once at a single point on the long road from farm to table. It is a sum, spread thinly across many stages and accumulated: spoilage in the field, gleanings left at harvest, shrinkage in transit, yield lost in processing, and finally the disposal that happens at the shop and in the home. That is precisely why food loss is not a problem solved by beating up one villain; it demands a view over the whole chain.

Newer figures tell us the situation has not improved. The UN Environment Programme's Food Waste Index Report 2024 estimated that in 2022 about 1.05 billion tonnes of food were thrown away at the retail, food-service and household stages. That is roughly 19 percent of the food that reached consumers, and about 60 percent of it came from households. More than a billion meals a day are wasted worldwide, the report says. In that same year, meanwhile, some 783 million people were said to be affected by hunger. We produce in abundance, discard much of it, and still leave people short — this gap sits at the very core of the food-loss problem.

When we throw food away, we throw away everything that went into making it. A single slice of bread has woven into it the water and land that grew the wheat, the energy burned to till and haul and bake, and the labour of everyone involved. Food loss means wasting all of those resources at once. The burden on the climate is especially large: food loss and waste are estimated to account for roughly 8 to 10 percent of global greenhouse-gas emissions. This comes not only from the fertiliser and fuel spent in the field, but because organic waste sent to landfill, breaking down in an oxygen-poor environment, releases methane — a far more potent greenhouse gas than carbon dioxide. The simple act of discarding quietly warms the planet.

What is easily overlooked is that the place where food is lost differs by country. In FAO's framing, developing countries lose much at the earlier stages — production, harvest, storage and transport — a 'food loss' rooted in shortages of refrigeration, roads and storage. In wealthy countries, by contrast, it is the 'food waste' discarded at the retail and consumer stages that stands out: cosmetic standards, margins of safety on date labels, over-producing, over-buying — waste born of plenty. The same 'food loss', then, has different causes and different remedies depending on the shape of a society. From here this column first grasps the shared science of why food spoils, and then examines the systems the world has built on top of it.