Globally, that's 1.3bn tonnes per year,

enough to end hunger many times over.

It's also responsible for more carbon emissions

than any country besides China and America.

But what can be done and how much waste is inevitable?

One often mooted solution is buying

more so-called ugly food, perfectly edible

produce that doesn't meet supermarkets

higher aesthetic requirements.

Startups like Misfits Markets, Imperfect Foods

and Hungry Harvest market this ugly food

to environmentally-minded eaters.

But critics maintain that this produce is seldom

actually wasted.

More likely, it would have ended up in a pie or a soup,

or been donated to a food bank.

The California-based non-profit ReFED analysed 27 ways

to reduce food waste and found the most effective were

solutions like education campaigns and changing

packaging sizes to prevent over purchasing.

Most promising of all was also perhaps the least glamorous

method, standardising date labels.

Confusion around sell by, best by, use by,

and the best before dates accounts for around 20

per cent consumer food waste, while loosening ugly produce

rules only ranked 18th out of 27.

But there must be buy-in from food producers,

and waste reduction doesn't always make business sense.

And customers who throw out edible food

usually buy even more from the grocery store.

The UN's Food and Agriculture Organisation

says that governments must step in and pressure

businesses to act.

Still, some win-wins exist.

Improving technology for predicting food demand

and tracking waste would limit over stocking, cutting

both costs and waste.

Ultimately, there are no silver bullets neither businesses,

governments, nor consumers can solve the problem alone.

Though a zero food waste world is unlikely, tackling the issue

can offer substantial financial and environmental payoffs.