Last week, the British retailer Marks & Spencer introduced a new packaging strip aimed at making strawberries shipped in from overseas last two days longer. Eventually, the company hopes to use the technology on all types of berries. Marks & Spencer says that because its strawberries will stay fresh longer, consumers can reduce food waste at home.
This is a modest initiative, but it is the latest in a difficult global battle against food waste. Around the world, a staggering one-third of food — or about 1.3 billion tons each year — is wasted, a study commissioned by the U.N. Food and Agriculture Organization estimated last year.
Environmentalists have campaigned aggressively against the waste of water and energy, but little attention is paid to the squandering of a product, food, that uses plenty of both.
The Food and Agriculture research, which was carried out at the Swedish Institute for Food and Biotechnology, estimated that in Europe and North America, 280 to 300 kilograms of food, or 620 to 660 pounds, per person are wasted each year. That is more than twice the figure for developing regions like sub-Saharan Africa and Southeast Asia.
In the developed world, consumers account for about one-third of the waste, discarding even food that is still edible.
The problem is a “‘disposing is cheaper than using or re-using’ attitude in industrialized countries,” the U.N. agency’s report says.
In developing countries, the problems are slightly different. Because of inadequate technology, most of the waste occurs before it gets to the consumer, while the food is being grown, processed and distributed.
For example, lack of refrigeration can cause milk to spoil on the way to market. A country like Tajikistan may not process as much rice as it grows, according to the F.A.O. report, because it does not have enough threshing and drying facilities.
At a time when prices are high for staples like corn, tackling waste has moved up the agenda. In addition to establishing biogas facilities that can process agricultural waste, some restaurateurs have started efforts to combat the problem.
In Britain, the Sustainable Restaurant Association, based in London, began a campaign last autumn to reduce waste.
It sends 250 “doggy boxes” — for taking uneaten portions home — to each participating restaurant. Some restaurants put stickers in their windows bringing the campaign to their patrons’ notice.
Of course, there is a tradeoff between more packaging and less food waste, but Tom Tanner, an S.R.A. representative, said the doggy boxes were made of recycled material and compostable.
The S.R.A. is also encouraging restaurants to waste less food in the kitchen, after a recent survey of 10 London restaurants found that they wasted about half a kilogram of food per customer per meal.
Mr. Tanner said that even though those restaurants already had a sustainability mind-set, many were unaware of the extent of the problem. About 65 percent of the waste stemmed from kitchen practices like throwing away vegetable peels.
But patrons accounted for about 30 percent of the waste. Some were too embarrassed to request to-go boxes, partly a function of “natural British reserve,” Mr. Tanner said. The S.R.A. hopes to extend its campaign to restaurants outside London.
“The days when you can just waltz into a restaurant, pay your money and say, ‘If it ends up in the bin, that’s fine’ — I don’t think so many people feel good about that,” Mr. Tanner said.
Some in the food industry say that the local food movement has highlighted the problem of waste and galvanized efforts to combat it.
In the past few years, “we’re seeing more food banks starting to get into perishable food, because there’s a focus on healthy food for people, particularly people who are low-income or struggling,” said Tonia Krauser, director of communications for Second Harvest, a Toronto charity that collects excess food donated from restaurants, food manufacturers and other places and redistributes it to agencies serving people in need.
Dave Krick, one of the owners of two Boise, Idaho, pubs called the Red Feather Lounge and the Bittercreek Alehouse, said he bought whole beef carcasses for his restaurants.
That forced the chefs to use different parts of the meat and to get creative with using new cuts, as well as soups and stocks.
Mr. Krick, a proponent of using local food, said he liked getting vegetables like beets “because we can use the entire thing. The beet greens are just as valuable as the beets.”
Reducing food waste, he added, is a “huge area of opportunity, really.”
Advocates of reducing food waste say that governments could do more to aid their cause.
In developing countries, improving roads to help food get to market faster without spoiling would help, the F.A.O. report suggested.
Ms. Krauser said that Second Harvest and other food-bank groups wanted the Canadian government to offer a tax credit for food donations.
European governments may get more involved; a resolution to be considered Thursday at the European Parliament meeting in Strasbourg calls for halving food waste by 2025, with help from awareness campaigns and other mechanisms.
The year 2013, the resolution says, should be designated the “European Year against Food Waste.”
Mr. Krick, in Idaho, has been working on another plan: reducing portion size, so consumers throw away less.
He has done this gradually, with items like salads and hamburger buns.
Reducing portion size allows him to charge customers less, he said — and they can order more if they are still hungry.
But there are limits. Some item sizes cannot be changed without provoking a backlash.
Mr. Krick said the amount of chips in his fish and chips offerings was staying the same.
“People like a large plate of fries, for whatever reason, so we haven’t messed with that,” he said.