We already know that 40% of food in the U.S. goes to waste, mostly because we buy too much and toss it in the trash. But food is also wasted at every stage of the production and supply chain, whether it’s because we feed crops to livestock that we then only eat part of, or toss produce before it hits stores because of its imperfect appearance. And there’s another form of food waste you might not even have thought about: over-consumption. By eating too much, we not only make ourselves fat and sick, but we waste food, and the resources that went into producing it.
A new study from the University of Edinburgh that quantifies the amount of food wasted over ten stages of the production cycle found that of the food that ends up in stores and on restaurant tables, we waste 20%. Half of that is thrown away or left to spoil, and the other half is wasted because of over-consumption. That’s right: Of all the food made available to humans, a tenth of it is sacrificed to gluttony.
But even that figure looks small in comparison to the food wasted before it gets anywhere near our tables. Overall, around half of all food produced goes to waste, and it breaks down like this:
First, livestock: Over a billion tons of food is grown and fed to livestock that results in 240 million tons of meat, milk, and eggs. This is the least efficient food production system, with losses of 78%, meaning we only consume around a quarter of what was grown. In the process, we lose around 840 million tons of food. Livestock farming also makes up around 14.5% of human-caused greenhouse gas emissions, which could be avoided if cut our meat consumption habits.
Food processing results in other big losses, because much of the raw product ends up being tossed. Take sugar–a good example because it’s the largest single-processed crop. Sugar beet and sugarcane come into the factories as substantial biomass, and are reduced through processing to a dry product. In 2011, 1,271 metric tons (Mt) of sugarcane and 247 Mt of sugar beet resulted in just 170 Mt of raw sugar, 9 Mt of non-centrifugal sugar and 56 Mt of molasses–a loss of 84%. Not only does the process waste a lot of water, but it also wastes everything in the cane that isn’t sugar: Protein losses, for instance, run at 92% for sugar.
Taken in this light, the food we waste by over-shopping and letting good produce spoil seems less significant. Still, as consumers, reducing our own waste is one of the most important ways we can reduce waste overall. The other, as made obvious by this study, is to eat fewer animal products–not just meat, but eggs, dairy, and anything else that requires crops be grown to feed animals instead of people. That doesn’t mean everybody needs to go vegan all at once: It considering plant-based options as your default protein. It would also help if scientists would hurry up and make vegan cheese that actually tastes as good as the real thing.