Almost 20% of the food made available to consumers worldwide is lost through over-eating or wastage, according to a new study. The world population consumes around 10% more food than it needs, while almost 9% is thrown away or left to spoil, researchers said.

Efforts to reduce the billions of tonnes lost could improve global food security—ensuring everyone has access to a safe, affordable, nutritious diet—and help prevent damage to the environment. Scientists at University of Edinburgh in the UK examined ten key stages in the global food system — including food consumption and the growing and harvesting of crops — to quantify the extent of losses.

 
What
  1. Using data collected primarily by the UN’s Food and Agriculture Organisation, the team found that more food is lost from the system than was previously thought.
  2. Almost half of harvested crops — or 2.1 billion tonnes — are lost through over-consumption, consumer waste and inefficiencies in production processes.
  3. Livestock production is the least efficient process, with losses of 78% or 840 million tonnes, the team found. Some 1.08 billion tonnes of harvested crops are used to produce 240 million tonnes of edible animal products including meat, milk and eggs. 
  4. This stage alone accounts for 40% of all losses of harvested crops.
  5. Increased demand for some foods, particularly meat and dairy products, would decrease the efficiency of the food system and could make it difficult to feed the world’s expanding population in sustainable ways.
  6. Meeting this demand could cause environmental harm by increasing greenhouse gas emissions, depleting water supplies and causing loss of biodiversity. Encouraging people to eat fewer animal products, reduce waste and not exceed their nutritional needs could help to reverse these trends.