No developing region is on track to meet the international goal of reducing the number of hungry people by half, a UN agency has warned.
Sub-Saharan Africa is among the worst-hit regions, the FAO says
Nearly six million children die from hunger or malnutrition every year, the Food and Agriculture Organisation says.
Many deaths result from treatable diseases such as diarrhoea, pneumonia, malaria and measles, the agency says.
They would survive if they had proper nourishment, the agency says in a new report on world hunger.
"Reducing hunger should become the driving force for progress and hope," FAO Director-General Jacques Diouf wrote in the report.
At the World Food Summit in 1996, world leaders announced a plan to halve the number of hungry people by 2015.
But Mr Diouf says this promise is likely to be broken.
This year's report concentrates on the wider impact of people not having enough food.
Poverty, illiteracy and disease are all made worse by hunger, the report says.
Malnourished children start school later and find it difficult to learn, and they are much more likely to die from disease, the report says.
Introducing the report in Rome, Mr Diouf said only South America and the Caribbean were on target to reduce the proportion of hungry people by half - and the goal of reducing the actual number of hungry people by half seems out of reach.
"None will reach the more ambitious World Food Summit goal of halving the number of hungry people," he said.
The report, based on data compiled last year, estimated that 852 million people were undernourished during 2000-2002.
In sub-Saharan Africa, the number of malnourished people has risen - to 203.5 million from 170.4 million 10 years previously, according to the new report.
The percentage of hungry people in the region has fallen slightly, from 36% to 33%.
The rate of improvement increased in sub-Saharan Africa and Latin America, but it declined in the Asia-Pacific region and the Middle East and North Africa.