Prices of staple foods will more than double in 20 years unless global food systems are overhauled, Oxfam has warned.

In a report on food security, the charity says the average cost of key crops will increase by 120% and 180% by 2030.

Changes in climate will contribute towards half of the increase, while scarcity of land, water and energy will also have an effect.

The report, Growing a Better Future, says it is vital world leaders improve the regulation of food markets and invest in a global climate fund if the world’s growing population is going to be fed.

The charity identifies four “insecurity hotspots” – areas which are already struggling to feed their citizens.

Guatemala, India, Azerbaijan and East Africa were all facing “chronic food shortages” or crippling food prices.

Barbara Stocking, Oxfam chief executive, said world leaders must agree new rules to govern markets and ensure poorer people did not go hungry.

“The food system must be overhauled if we are to overcome the increasingly pressing challenges of climate change, spiralling food prices and the scarcity of land, water and energy,” she added.

“We are sleepwalking towards an avoidable age of crisis – one in seven people go hungry every day despite the fact that the world is capable of feeding everyone.”

Oxfam says governments must increase transparency in commodities markets and regulate futures markets, as well as scaling-up food reserves.

It also says leaders should put an end to promoting biofuels and invest in smallholder farms and women in agriculture.

“We are sleepwalking towards an avoidable age of crisis,” said Ms Stocking.

“One in seven people on the planet go hungry every day despite the fact that the world is capable of feeding everyone.”