SHOCKING new research has revealed that almost 20 per cent of the food made available to consumers is lost through waste or over-eating.

Researchers found the world population consumes around 10 per cent more food than it needs - while almost nine per cent is thrown away or left to spoil.

And they claim efforts to reduce the billions of tonnes lost could improve global food security and help prevent damage to the environment.

Scientists at the Universities of York and Edinburgh examined 10 key stages in the global food system, including food consumption and the growing and harvesting of crops, to quantify the losses - and found that more food was lost from the system than was previously thought.

Almost half of harvested crops – or 2.1 billion tonnes – were lost through over-consumption, consumer waste and inefficiencies in production processes.

And the team found livestock production was the least efficient process, with losses of 78 per cent or 840 million tonnes.

Some 1.08 billion tonnes of harvested crops were used to produce 240 million tonnes of edible animal products including meat, milk and eggs – and that stage alone accounted for 40 per cent of all losses of harvested crops.

The researchers say increased demand for some foods, particularly meat and dairy, would decrease the efficiency of the food system and could make it difficult to feed the world’s expanding population in sustainable ways.

Meeting that demand could also cause environmental harm by increasing greenhouse gas emissions, depleting water supplies and causing loss of biodiversity.

However encouraging people to eat fewer animal products, reduce waste and not exceed their nutritional needs could help to reverse these trends, the team said..

Professor Dominic Moran, of the University of York said: “This study highlights that food security can only be sustainably achieved through holistic approaches because consumer behaviours, as well as the actions of food producers and processors, all influence the sustainability of the food system.

“To date, much of the focus has been overly dominated by improving production efficiency.”

The study was published in the journal Agricultural Systems.