The world's poorest nations are set to nearly triple spending on nutrition programs for mothers and children over the next two years to help cope with volatile food prices, the World Bank said.

The Washington-based global development lender said its direct funds for nutrition programs should rise to $600 million for 2013-14 from $230 million in 2011-12.

Ninety percent of those funds will be disbursed through the World Bank's fund for the poorest, the International Development Association (IDA), and go largely to Africa and South Asia.

Countries ask the World Bank for IDA funds for specific programs, said Keith Hansen, the World Bank's acting vice president for human development.

"(The higher funds) signal that there is growing demand from countries themselves, ... as countries learn about the high health and social returns that nutrition creates," Hansen said.

Worldwide, about 165 million children below the age of 5 are malnourished. Malnutrition is the single biggest cause of child mortality, contributing to a third of all child deaths.

Even as countries' incomes rise, better nutrition may not follow. In India, for example, the economy has tripled between 1990 and 2005, but 42 percent of children under 5 were underweight in 2012, similar to rates five years earlier.

And recent spikes in food prices have made the situation worse, stalling global progress in reducing the rates of child and maternal mortality, the World Bank found in a report last year.

The United Nations' food agency has said global food prices are likely to remain high this year, and low stocks pose the risk of sharp price increases if crops fail.

The world's poorest are particularly sensitive to big swings in food prices as they spend a large chunk of their income on food. In response to higher prices, households will often buy cheaper foods like rice or maize that have fewer nutrients, Hansen said.

The World Bank's nutrition programs focus especially on children 2 years old or younger, when nutrition interventions can have the biggest impact. – Reuters