Soaring food prices have added at least 75 million people to the world's hunger rolls, the United Nation's Food and Agricultural Organization says.

The increase brings the total number of undernourished people worldwide to 923 million, up from 848 million in 2005, said Hafez Ghanem, the agency's assistant director general for economic and social development.

"We see a big jump in the number of hungry people over the last two years," Ghanem said Thursday.

Although the UN had hoped to cut world hunger in half by 2015, he said the higher food prices have probably put that goal out of reach.

The rising cost of food — which has increased by 52 per cent in the past year — as well as higher prices for fuel and fertilizer have created "worrisome trends," Ghanem said in a news release.

Hunger has continued to increase in the past decade despite the fact the world has become richer and produced more food than ever, he said.

Hunger is a cause of poverty, not just a consequence of it, said Kostas Stamoulis, an economist with the agency.

The cost of hunger — in terms of the resources needed to deal with its effects and the value of productivity and income losses — is estimated to be in the hundreds of billions of dollars a year, he said.

The countries most affected by hunger are in Africa. The UN agency said in addition to getting more food to people who need it, more must be done to help small-scale farmers increase their production.