Billions of tons of food are wasted because of inadequate storage, strict sell-by dates and a desire for cosmetically perfect food, a British report says.

The report by the Institution of Mechanical Engineers has found as much as 50 percent of all food produced around the world is never consumed and ends up as waste.

The report, "Global Food, Waste Not Want Not," said the world produces about 4.4 billion tons of food per year but wastes as much as half of it through poor practices and inadequate infrastructure.

"The amount of food wasted and lost around the world is staggering," Tim Fox, the institute's head of energy and environment, said.

"The reasons for this situation range from poor engineering and agricultural practices, inadequate transport and storage infrastructure through to supermarkets demanding cosmetically perfect foodstuffs and encouraging consumers to overbuy through buy-one-get-one free offers," he said in an institute release Thursday.

With the United Nations predicting the world will have another 3 billion people to feed by the end of the century, and increasing pressure on the resources needed to produce food -- including land, water and energy -- urgent action is needed, the report said.

"This is food that could be used to feed the world's growing population -- as well as those in hunger today," Fox said.