Governments could take a big step towards ending world hunger by spending just $1.2 billion a year in developing nations on dietary supplements and education about the food needs of babies, a study showed on Friday.

Such targeted spending to help a billion of the poorest people in Africa and Asia could save millions of lives and bring annual economic benefits of more than $15 billion in lower health bills and longer and more productive lives, it said.

"Hunger and malnutrition are responsible for millions of deaths. But there are relatively inexpensive ways to help address the problem," said Susan Horton, of Wilfrid Laurier University in Canada who was one of three authors of the report.

The study, issued before annual World Health Day on April 7, is one of a series commissioned by The Copenhagen Consensus, a project by Danish statistician Bjorn Lomborg about the costs of solutions to world problems ranging from AIDS to terrorism.

The total cost of adding micronutrients such as iron to flour to curb anaemia, of providing vitamin A capsules to help children's eyesight and immune systems and of adding iodine to salt to avert thyroid damage was estimated at $347 million.

The study, written by Horton with specialists from the World Bank and Mexico's National Institute of Public Health, estimated such micronutrient measures would mean annual benefits of $5 billion from improved health.

And it said that education about nutrition, largely to promote breast-feeding of babies, would cost about $798 million and bring annual benefits of $10 billion.

Projects to give medicines to kill off worms and other intestinal parasites among pre-school children would cost about $27 million a year and bring benefits of $159 million.

"The long-term solution to hunger has to be poverty reduction and improving food availability," Horton said.

"In the meantime, we suggest a few things that will help a lot: micronutrients...and educating people about the most vulnerable age -- the weaning age for children when their brains are growing," she told Reuters.

Halving by 2015 the proportion of people on the planet who suffer from hunger -- now almost a billion people -- is among the Millennium Development Goals set by the world in 2000.