Hunger is costing the world's poorest nations $450bn (£290bnn) a year, according to a report published today.
The figure is more than 10 times the estimated amount needed to meet the United Nations Millennium Development Goal (MDG) of halving global hunger by 2015, said the report by charity ActionAid.
The UN will gather in New York next week to assess progress towards the eight goals set in 2000, with Deputy Prime Minister Nick Clegg representing the UK.
But with just five years to go to the MDG deadline, today's report warned that many countries were going backwards on the crucial hunger pledge, with more people under-nourished than a decade ago.
If the massive gains made in China are excluded, global hunger rose to the same level in 2009 as it was in 1990, with 500 million more people chronically malnourished than if the UN goal had been met, said ActionAid.
The charity warned that hunger has a cost not only in premature deaths, but also in lost economic potential. Developing economies are losing out to the tune of $450bn a year because their people are too hungry to work or because hunger in childhood has left irreversible damage to their mental and physical capacities.
ActionAid said "political will" was the key to hitting the 2015 target, pointing to success stories like Brazil, which has halved the number of underweight children in less than a decade, and Malawi, where numbers living on food handouts have been cut from 4.5 million to 150,000 in just five years.
The charity urged the rich world to make good on $22bn (£14bn) to fight hunger pledged at last year's G8 summit in Italy.
And it called on Mr Clegg and the new coalition Government to "show leadership" by prioritising hunger as a key development issue.
Britain ranks seventh in the ActionAid league table of 23 donor countries - and fourth for aid to agriculture. But the charity warned the coalition must not allow the UK to "fade as a leading light in global development".
ActionAid head of policy Meredith Alexander said: "On the eve of the most important development summit for five years, a billion people will be going to bed hungry.
"Despite promises to the contrary, one-sixth of humanity doesn't get enough to eat. But we grow enough food to feed every man, woman and child on the planet.
"The real cause of hunger isn't lack of food, it is lack of political will. In Brazil, President (Luiz Inacio) Lula made beating hunger a personal priority and the country has cut child malnutrition in half.
"For the last 10 years, the UK has been at the forefront of tackling global poverty. The challenge for Nick Clegg is to show the same kind of leadership on hunger as the UK has demonstrated on education, HIV and Aids and debt relief."
Today's report, entitled Who's Really Fighting Hunger?, reveals just eight out of a group of 28 poor nations are on track to meet UN goals on halving hunger and numbers of underweight children by 2015.
Some 12 countries are going backwards, and even in India, currently undergoing an economic boom, failure to invest in agriculture and small farms means nearly half of the country's children are malnourished and one in five of the population is hungry.
Globally, 20% more people are going hungry now than when the MDG goals were conceived, said the report.Reuse content