Lectures on waste are ubiquitous in the modern world. Baths waste water. Babies waste nappies. Google searches waste carbon. On the topic of waste, the green media has adopted the stance of old-fashioned parents telling their children to eat their scraps and think of the starving in Africa. And we in turn have become like those children, putting our fingers in our ears and ­carrying on as normal.

It is therefore a testament to the power of ­Tristram Stuart’s jaw-dropping study of food waste that so much of what he says comes as a genuine shock. His message is extremely simple. We waste food. A lot of it. Every day. And that is very wrong. To which we might be tempted to reply: tell us something we don’t know. But what makes this book so compelling — a must-read, in fact — is the astonishing level of detail.

Every year in the UK, Stuart tells us, we throw away 1.6 billion apples, 27 for every person in the land — many of us, apparently, are flinging our five-a-day straight into the bin. We also chuck 484m unopened yoghurts, 2.6 billion slices of bread and £6-worth, each, of bananas. Stuart disputes the 2008 statement by Wrap (the Waste and Resources Action Programme) that Britons throw away a third of all the food we buy. Wrap included things such as tea bags and orange peelings “which no one eats”. But ­Stuart’s figure is scarcely better — he reckons that around 5.4m tonnes per year, or a quarter of all we buy, is wasted.

There is plenty that individuals can do to address the problem. As Stuart says, we can embrace leftovers, compost our peelings, learn to love offal, measure food portions more carefully and store lettuces (the most wasted food of all) upright in water, like flowers, so that they keep for longer. But before you start getting too smug about your wormery, think again. Even those who don’t chuck much of their own food are still — unwittingly — participating in a system that generates preposterous levels of waste, much of it hidden from our gaze.

Do you ever eat M&S sandwiches? The Hain Celestial Group, which makes sandwiches for M&S, are required to discard four slices from every loaf, the crust plus the first slice from either end. A single factory wastes around 13,000 slices of perfectly edible fresh bread every day. Since 2001, in the wake of foot and mouth, pig swill has been banned (on pain of a possible two-year prison sentence for farmers). As a consequence, pig farmers are driven to fritter away thousands of pounds buying soymeal feed, much of it from Brazil, with the knock-on effect of the deforestation of the Amazon. Food manufacturers are forced to waste thousands of pounds disposing of perfectly good swill. And millions of tonnes of valuable food are sent to landfill.

As a freegan (one of those middle-class foragers who choose to live out of rubbish bins) Stuart has valuable insights into the feasts that get thrown away. He once catered for a cousin’s wedding with 25 boxloads of “the ripest organic mangoes”, picked up free from ­Spitalfields market. At least the traders at Spitalfields were happy for him to take them. By contrast, many British supermarkets do ­everything they can to prevent leftover stock being eaten, preferring to lock up skips full of food that is just past its sell-by-date, rather than giving it to staff or sending it to charity.

Why do they do this? Because “empty shelves put people off”, Stuart is told. In other words this, like so much food waste, is not accidental, but built into the system. Businesses lose less money from throwing food away than they do from losing customers, who want to be given the impression of abundance at all times.

Nor is the problem limited to supermarkets. At an upmarket sandwich chain, Stuart witnesses staff opening packets of leftover sandwiches and salads “and tipping the food into a dirty mess before putting the sacks out onto the street”. Most shocking of all, he sees a sushi bar disposing each day of “trays and trays of neatly prepared prawn, salmon, swordfish and tuna sushi or sashimi” — at a time when stocks of wild fish are at an all-time low. It is like throwing away gold.

Stuart is surely right that “reducing food waste should become one of the highest priorities on the environmental agenda”. It’s a no-brainer: good for the hungry (North America and Europe combined chuck out enough to feed the world’s hungry three times over), good for the environment (excess food production is directly linked to the destruction of the rainforest) and even good for business (“where waste has been cut, profit margins soar”).

The book’s message, though, would have been even more powerful if Stuart could have resisted the environmentalist’s urge to nag. He chastises those of us who don’t eat our crusts (“if you don’t like crusts, don’t eat bread”) and applauds China’s one-child policy. There is a faint utilitarian suspicion that he might like us to breathe less, as well as eat less. But when it comes to food waste, Stuart has an unanswerable case. We need to take our fingers out of our ears and listen.

Waste by Tristram Stuart
Penguin £9.99 pp480

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