( dpa ) - "The new face of hunger" is the biggest challenge facing efforts to feed the world's hungry, World Food Programme Executive Director Josette Sheeran said in an interview with Deutsche Presse-Agentur dpa Thursday.
Food was in plentiful supply but people could no longer afford it.
"These are people who are simply being priced out of the food markets and it involves more urban poor than typically we see with urgent hunger needs," she said.
"We are seeing a new face of hunger where there is food available but people can't access it."
Escalating fuel and food costs had cut into the budget of the World Food Programme (WFP).
"Our estimate is that we are able to procure 40 per cent less food than in 2002 for the same amount in real dollar terms."
This was happening, she said, at a time when the number of hungry people was increasing as a result of an increasing population, even while the proportion of the world's hungry has halved from around 37 per cent since the early 70s to 16 per cent today.
"While the world is nourishing more people than ever before in human history we are also seeing more hungry because we are not keeping up with the population growth."
Last year the UN agency's food assistance reached 63.4 million people caught in a growing number of food emergencies.
Urgent situations had risen in the past two decades, from an average of 15 per year during the 1980s to more than 30 per year since the turn of the millennium, according to WFP figures.
As the need grows, the escalating cost of fuel and its knock-on effect on food prices has cut into the WFP budget.
"Since 2002 our costs of transporting and of procuring food has gone up 70 per cent." Twenty per cent of that was in the past year alone.
In response, the WFP has increased its programme of local procurement, buying food at local markets near to where the need lies.
"Of the cash we have for procurement which is about half our budget we spend 80 per cent of it in the developing world. This helps poor farmers and is part of the solution but we're able to reach fewer people with the same budget."
Last year, a record 21 million tons of food worth 760 million US dollars was bought in developing countries.
As well as oil prices, extreme weather events, drought in Australia and floods in Africa had driven up the cost of food.
So had the increasing demand for better food by the increasingly prosperous populations of emerging countries such as India. More people could now afford more food.
Sheeran said the message for potential donors was: "A static budget will not reach the same numbers of people. What we have had to do in the past year is sometimes cut rations to deal with rising food costs."
She added: "In this past year we have not been able to reach all the people that we assessed as urgently in need of a food intervention."
"It isn't that there is less food in the system but there is more demand for what's in the system for different and varying purposes."
Alternative sources of energy such as biofuels were valuable and could be helpful for local farmers but Sheeran said it was important to look at crops which were not part of the food chain.
Sheeran was speaking from inside a replica of a mud hut but it was far from Africa. The WFP has set up camp on the fringes of Davos where it can actively pursue the corporate donors it needs if it is to raise the extra 20 per cent for its budget next year just to stand still.
The WFP's mission in Davos is set to be boosted by the World Bank President Robert Zoellick who is expected to call on world leaders gathering in the Swiss resort to make the fight against hunger and malnutrition a global priority or risk undermining development strategies.
"The message coming from the World Bank is that we need to renew the focus and renew our efforts on hunger."
Sheeran added: "I think pulling together the proper strategy is most important so we can make sure we are meeting the face of hunger today which is frankly different from where we were a couple of years ago."