One in eight people around the world is chronically undernourished, the United Nations' food agencies has warned.

In their latest report on food insecurity, the UN agencies estimated that 842 million people were suffering chronic hunger in 2011-13, 12 per cent of the world's population.

The figure was down 17 per cent from 1990-92 and the new total was lower than the last estimate of 868 million in 2010-12 and 1.02 billion in 2009, but the bodies said progress was uneven in meeting the Millennium Development Goal to halve hunger by 2015.