The UN says 1.3 billion tonnes of food is wasted each year and is launching a campaign to encourage producers, retailers and consumers to reduce these losses.
The Food and Agriculture Organisation (FAO) believes one-third of all food produced, worth around US$1 trillion, is lost or wasted in food production and consumption systems.
The Think, Eat, Save, Reduce Your Foodprint campaign is an initiative from the UN Environment Programme and FAO aimed at raising awareness of food waste around the world.
"In a world of seven billion people, set to grow to nine billion by 2050, wasting food makes no sense – economically, environmentally and ethically," said UN Under-Secretary-General and UNEP Executive Director Achim Steiner.
"Aside from the cost implications, all the land, water, fertilizers and labour needed to grow that food is wasted – not to mention the generation of greenhouse gas emissions produced by food decomposing on landfill and the transport of food that is ultimately thrown away," he added.
Food waste levels have huge implications for the environment and efforts to address climate change.
Agriculture and land use changes such as deforestation contribute to more than 30% of total global greenhouse gas emissions, while globally, the agri-food system accounts for nearly 30% of energy consumption.
Last week a report from the UK's Institute of Mechanical Engineers (IMechE) has found that 30-50%, or 1.2-2 billion tonnes of produced food is wasted by poor storage, bad distribution and exacting quality standards in the developed world.
In the developing world the FAO says 95% of food loss occurs at the start of the food supply chain due to limited harvesting, storage and packaging capabilities.
In contrast much of the food in the developed world is discarded at the user end, either by supermarkets or consumers.
According to waste campaigners WRAP, the average UK family could save £680 per year (US$1,090) and the UK hospitality sector could save £724 million (US$1.2 billion) per year by tackling food waste.
"Together, we can reverse this unacceptable trend and improve lives. In industrialized regions, almost half of the total food squandered, around 300 million tonnes annually, occurs because producers, retailers and consumers discard food that is still fit for consumption," said José Graziano da Silva, FAO Director-General.
"If we can help food producers to reduce losses through better harvesting, processing, storage, transport and marketing methods, and combine this with profound and lasting changes in the way people consume food, then we can have a healthier and hunger-free world," Graziano da Silva added.
Shop Smart: Plan meals, use shopping lists, avoid impulse buys and don't succumb to marketing tricks that lead you to buy more food than you need.
Buy Funny Fruit: Many fruits and vegetables are thrown out because their size, shape, or colour are deemed not "right". Buying these perfectly good fruit, at the farmer's market or elsewhere, utilizes food that might otherwise go to waste.
Understand Expiry Dates: "Best-before" dates are generally manufacturer suggestions for peak quality. Most foods can be safely consumed well after these dates. The important date is "use by" – eat food by that date or check if you can freeze it.
Zero Down Your Fridge: Websites such as WRAP's www.lovefoodhatewaste.com can help consumers get creative with recipes to use up anything that might go bad soon.
Plus: Freezing food; following storage guidance to keep food at its best, requesting smaller portions at restaurants; eating leftovers – whether home-cooked, from restaurants or takeaway; composting food; and donating spare food to local food banks, soup kitchens, pantries, and shelters.