The £20bn food mountain: Britons throw away half of the food produced each year

20m tons of food is chucked out from homes and supermarkets, enough to meet half of Africa's food import needs. By Susie Mesure

Britain is throwing away half of all the food produced on farms, according to the starkest estimate yet of the amount of edible produce we waste.

About 20m tons of food is thrown out each year: equivalent to half of the food import needs for the whole of Africa. Some 16m tons of this is wasted in homes, shops, restaurants, hotels and food manufacturing. Much of the rest is thought to be destroyed between the farm field and the shop shelf.

The total bill to the nation is estimated to be more than £20bn. The issue has come to the fore as supermarkets fight off criticism over billions of plastic carrier bags handed out free each year.

Lord Haskins of Skidby, a former government adviser on rural affairs and chairman of Northern Foods, said yesterday that tackling the mountain of food wasted in this country every year would help to preserve the environment and go some way towards feeding an expanding global population in the face of unprecedented food shortages.

In a move that illustrated the problem last week, Japan pledged more than 300m yen in food aid for Burundi, in Africa, where malnutrition runs at 44 per cent. The food thrown away in the UK last year would meet the equivalent of Burundi's shortages more than 40 times over.

Lord Haskins' estimate of the scale of food waste suggests the problem in the UK is far greater than previously imagined and came as global food prices hit new records. The United Nation's World Food Programme has admitted it might have to ration food aid in response to rocketing global food prices that have soared by more than 75 per cent since their lows of 2000, jumping by more than a fifth last year alone, prompting riots in some countries.

Consumers, in thrall to use-by dates and lured by supermarket multi-buy offers, are the biggest culprits, throwing away one-third of everything they buy, according to the Waste & Resources Action Programme, the Government's waste watchdog. The National Consumer Council will highlight the issue of buy-one-get-one-free promotions, which exacerbate the problem of food waste, in a campaign this spring.

Lord Haskins, whose former employer is one of Britain's largest food suppliers, urged governments to press their citizens to help "avoid disaster by dramatically reducing the ... unacceptable levels of food waste, which are a shameful feature of most modern consumer societies". He called recent controversy over supermarkets' free distribution of plastic bags "a red herring".

Tony Lowe, the chief executive of FareShare, the national food charity, said: "Unfortunately, we live in a world where many people do not have access to food in general, and good-quality food specifically, while at the same time millions of tons of perfectly fine food are being disposed of. In the UK alone, the extent of food poverty is staggering, as millions of people with low or no income find it harder to access affordable, nutritious food."

Estimates that the world's population will rise by 30 per cent over the next 50 years to around 8.5 billion have raised the spectre of a global food shortage too big for farmers to meet, Lord Haskins said. "If consumers ate a bit less and wasted a bit less you'd help to solve the problem. If the world was vegetarian then you'd solve the problem completely." One-third of wheat grown globally is fed to livestock reared to end up on the dinner table.

Experts believe that Lord Haskins might struggle to get people to listen. Tim Lang, food policy professor at City University, said: "Waste is a fundamental part of the food economy and it will be hard to get rid of. I do not see how simply appealing to morals will do it."

However, chefs, whom Lord Haskins berates for serving vast portions, claimed they do work hard to waste less. Michelin-starred Tom Aikens said: "It's morally wrong to throw away any food. To reduce waste you have to separate the food from the recycled objects so you can see the waste and then do something about it. If I could I would recycle the food waste, but unless regulations change or I can stick a wormery on my restaurant roof, then not a lot will change."

Supermarkets are very defensive on the subject of food waste. A Tesco spokesman said the retailer, which has not published figures showing how much it sends to landfill since 2004, wasted less than 1 per cent of its food each year. Waitrose, which alone of the big chains sells off "ugly" fruit and vegetables cheaply, said: "It is not in our business interests to produce any waste at all, so our branch managers work very hard to minimise it."

A spokesman for the British Retail Consortium said: "Retailers are working closely with suppliers to minimise waste through analysing the supply chain."

But Lord Haskins said supermarkets compound the issue of food wasted in the supply chain by giving suppliers far too little notice of their orders or cancelling orders at the last minute.

Help the planet...

The Independent on Sunday's top 10 tips to help you cut that food-waste mountain rotting in your bin:

1. Buy less if you don't think you can eat it: smaller joints, loose vegetables rather than pre-packed bags that are too big – and try not to fall for quite so many buy-one-get-one-free offers.

2. Use your imagination with leftovers: that half a roast-chicken would make a perfect pie, sandwich filling or form the basis for a salad.

3. Don't let vegetables rot in the bottom of the fridge: even older vegetables make decent soups, casseroles or curries.

4. Remember to cancel that vegetable box if you're going to be dining out a lot that week.

5. Don't over-order in restaurants; if you do, make like an American and ask for a doggy bag.

6. Use common sense rather than use-by dates when deciding what to throw away.

7. Become friends with your freezer: make your own frozen ready-meals with last night's leftovers or any food that you have overbought.

8. Whiz up older fruit into a smoothie or bake it in a pudding.

9. Look out for the new plastic bags that will give your vegetables a longer lease of life in your fridge.

10. Try and shop more frequently so that you buy what you need, rather than rely on one major shopping trip.

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