As much as half of all the food produced in the world - two billion tonnes worth - ends up being thrown away, according to "staggering" new figures.
Poor storage facilities, over-strict sell-by dates, "get-one-free" offers, and consumer fussiness all contribute to the waste, according to the Institution of Mechanical Engineers.
"This is food that could be used to feed the world's growing population - as well as those in hunger today," said Dr Tim Fox, head of energy and environment at the IME.
"The amount of food wasted and lost around the world is staggering.
"It is also an unnecessary waste of the land, water and energy resources that were used in the production, processing and distribution of this food."
Half of all food gets thrown away
Each year countries around the world produce some four billion tonnes of food. Between 30% and 50% of this total, amounting to 1.2 to two billion tonnes, never gets eaten, says the report Global Food; Waste Not, Want Not.
In the UK, up to 30% of vegetable crops are not harvested because their physical appearance fails to meet the exacting demands of consumers.
30% of food never even reaches the market because it doesn't look right
Half the food purchased in Europe and the US is thrown away after it is bought.
Vast quantities of water are also wasted in global food production, it is claimed, with around 550 billion cubic metres of water is used to grow crops that never reach the consumer.
Producing one kilogram of meat is also said to take 20 to 50 times more water than producing the same weight of vegetables.
Chris Mould, director of the Trussell Trust, the UK's largest provider of food banks, told the Huffington Post UK the report was "shocking." He said food waste needed tackling urgently, especially as more and more people were struggling to provide food for their families.
"In our experience and over the last few years and particularly recently there has been a huge rise in the number of people struggling to get food on the table.
"We’ve doubled the number of food banks over the last year alone and the need is growing fast. If we’ve got more and more people visiting food banks and very substantial food waste happening then we should be looking at a policy initiative to change that. This is an urgent issue, a complicated issue and one that we need to collaborate on to do something about."
Volunteers Hugh Mullens and Sally Hewitt, with Salisbury food bank manager Louise Wratten
By 2075 the United Nations predicts that the world's population will reach around 9.5 billion, resulting in an extra three billion mouths to feed.
Added stresses on the ability of the world to feed itself include global warming and the growing popularity of meat, which requires around 10 times more resources than staple plant foods such as rice or potatoes.
The demand for water in food production could reach 10 to 13 trillion cubic metres a year by 2050, the institution said.
This is up to 3.5 times greater than the total amount of fresh water used by humans today, raising the spectre of dangerous water shortages.
Dr Fox added: "As water, land and energy resources come under increasing pressure from competing human demands, engineers have a crucial role to play in preventing food loss and waste by developing more efficient ways of growing, transporting and storing foods.
"But in order for this to happen governments, development agencies and organisation like the UN must work together to help change people's mindsets on waste and discourage wasteful practices by farmers, food producers, supermarkets and consumers."
Richard Dodd, spokesperson for the British Retail Consortium, told the Huffington Post UK that the report "is significantly overstating the issue."
"Food waste is dramatically lower and is nothing like as extreme as this report claims.
What this report doesnt recognise is that really significant gains have been made by both food retailers and households over the past few years.
"There’s less use of two for one offers in supermarkets but they still do have a role to play. Its about encouraging extra sales of seasonal produce at times of glut. It is a way of reducing food waste at farm levels, not about selling customers produce they dont want.
"Sell by dates are aimed at store staff, not at customers. Often customers dont properly understand the difference btween best before dates and use by dates."
A Morrisons spokesperson said:“We don’t currently offer buy one get one free offers on our fruit and vegetables, have relaxed our specifications on this produce to accept more ‘wonky’ crops and offer clear labelling for customers.”
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