Make a shopping list and buy "funny fruit" to cut food waste and help the world "shape a sustainable future," two UN agencies have urged.
The United Nations Environment Program (UNEP), Food and Agriculture Organisation (FAO) and partners on Tuesday unveiled a campaign dubbed Think-Eat-Save Reduce Your Foodprint to change global practices that result in the loss of 1.3 billion tonnes of food each year.
The program is aimed primarily at consumers, food retailers and the hotel and restaurant industry, and is based on three recommended actions: think, eat, and save.
"In a world of seven billion people, set to grow to nine billion by 2050, wasting food makes no sense - economically, environmentally and ethically," a statement quoted UN Under-Secretary-General and UNEP Executive Director Achim Steiner as saying.
"We're doing something that is completely irrational," he lamented to reporters in Geneva, before adding that he hoped the campaign would "literally mobilise tens of millions of people to become part of the solution."
FAO Director General Jose Graziano da Silva pointed out that in industrialised nations, around 300 million tonnes of food are wasted each year, "because producers, retailers and consumers discard food that is still fit for consumption."
That is more food than is produced in sub-Saharan Africa, and is enough to feed the estimated 830 million people who now go hungry worldwide, he added.
The program estimates the overall cost of wasted food at about $US1 trillion ($NZ1.1 trillion) per year, with most losses occurring in production stages - such as harvesting and distribution - and blamed on problems from storing food in difficult climatic conditions to unreliable harvests.
It is retailers and consumers, whoever, who are usually guilty of wasting food.
Consumers can participate in a global effort by respecting a few simple recommendations, the UN agencies said.
Planning meals, making shopping lists and avoiding impulse buying helps, as does staying alert "to marketing tricks that lead you to buy more food than you need."
Another good idea is to "buy funny fruit" or vegetables that would otherwise be thrown out because their size, shape or colour do not meet market standards.
Tristram Stuart of the Feeding the 5000 campaign told reporters in Geneva: "Wonky fruit and vegetables are very often left on farms across Europe and North America simply because they don't meet the cosmetic standards of retailers, and they are left on fields to rot."
People, he insisted, must "adopt the value that food is simply too good to waste."
Paying attention to expiry dates and "zeroing down your fridge" with recipes that use up food set to go bad helps, the UN agencies said, as does freezing food, asking restaurants for smaller portions, eating leftovers, composting food or donating it to food banks, soup kitchens and shelters.
Retailers can offer discounts for food that is nearing its sell-by date, standardise labels and donate more food.
Restaurants were urged to "limit menu choices and introduce flexible portioning," to audit how much food they waste, and to set up "staff engagement programs."
Finally, an internet site, thinkeatsave.org is to serve as a global platform for sharing information on other initiatives that people come up with.