The UN Food and Agriculture Organisation (FAO) warned in its annual report that the number of hungry people in the world is falling too slowly and that steps to fight under-nourishment are inadequate.
Out of a population of six billion, "826 million people still do not get enough to eat in a time of unprecedented plenty".
Current FAO projections indicate that unless extra efforts are made to accelerate progress, the World Food Summit goal of cutting the number of undernourished to 400 million by 2015 will not be achieved before 2030. "Hungry people cannot wait another 15 years," the report said.
Societies with hunger are also societies with a high infant mortality rate and significantly lower life expectancy.
In addition to increasing susceptibility to disease, chronic hunger also means that children may be listless and unable to concentrate in school.
There are more chronically hungry people in Asia than in any other part of the world, but the problem is clearly worse in sub-Saharan Africa, where the undernourished, in 19 countries out of 46, have an average deficit of more than 300 kilocalories per person per day.