Discuss as:

Half of world food goes to waste, global study says

Bay Ismoyo / AFP - Getty Images

Indonesians buy staple foods as vendors mind their stalls at a traditional street market in Jakarta on Jan. 3.

As much as half of the food produced worldwide ends up being thrown away every year because shoppers are too choosy about the appearance of fruit and vegetables, a report said Thursday.

The world produces about four billion metric tonnes of food a year but up 2 billion tonnes is never eaten, the global study by the London-based Institution of Mechanical Engineers said.

The organisation lays the blame at every step of the food chain, from farming practices to consumers.

It says retailers reject millions of tonnes of crops because of the physical appearance of fruit and vegetables, fearing shoppers will not buy them unless they look perfect.

Related: U2's Bono talks curbing hunger with NBC's Andrea Mitchell

The institution is also calling for a change in farming practices and also a change in how we all think and value the food we buy. 

"With current practices wasting up to 50 percent of all food produced, engineers need to act now and promote sustainable ways to reduce waste from the farm to the supermarket and to the consumer," the report said.

Food consumption is becoming an important global issue. By the end of the century the world could have an extra 3 billion people to feed, according to the United Nations.