"We have to take note that the efforts made to date have not significantly reduced the number of people in the world who suffer from hunger," Benedict said in a message read by the Vatican's envoy to the Food and Agriculture Organization (FAO) at its Rome headquarters.
The failure to provide food was mostly due "to human behaviour and a general worsening in social, economic and human conditions," read Monsignor Renato Volante from the pontiff's World Food Day message to the Rome-based United Nations agency.
"It is necessary that a conscience of solidarity which considers food a universal right without discrimination matures within the community of nations," Benedict wrote.
"Hunger is not an inescapable destiny, but can of course be eliminated by wise policies," said German President Horst Koehler in his address at the FAO ceremony.
"This (the elimination of hunger) requires first and foremost that the governments of the developing countries make food security for their populace a priority goal," Koehler said.
"40,000 children die every day throughout the world due to malnutrition and related diseases. These are the people who are being denied the right to food. These are the people who are the subject of this year's World Food Day," said Tanzanian Jakaya Mrisho Kikwete.
Earlier, FAO Director-General Jacques Diouf opened Tuesday's ceremony with a grim reminder based on the FAO's estimates on world hunger.
"Our planet produces enough proper food to feed its entire population. Yet, tonight, 854 million women, men and children will be going to sleep on an empty stomach," he said.
But Diouf also pointed to the success achieved in some developing countries, singling out Brazil where "this right [to food] is now firmly entrenched and hunger is in retreat.
FAO celebrates World Food Day each year on Oct 16, the day the organization was founded in Quebec City, Canada, in 1945.