Image caption Asia suffers the highest incidence of malnourishment, the FAO says

Global hunger has fallen this year but remains "unacceptably high", a report from the UN's Food and Agriculture Organization (FAO) has said.

The FAO estimates there are 925 million undernourished people in 2010, compared with 1.02 billion in 2009.

But it warned that the fight to reduce hunger would face additional obstacles if food prices continue to rise.

A separate report from Action Aid estimates that hunger costs developing countries $450bn (£292bn) a year.

The report says that 90% of these costs stem from lost productivity as a result of malnutrition, while the other 10% is due to higher health system costs.

Action Aid says this is more than 10 times the amount of funding needed to halve hunger by 2015. This is one of the eight United Nations Millennium Development Goals (MDGs).

The MDGs represent a global commitment by members of the UN to reduce poverty and improve lives by 2015.

Targets under threat

Food prices have risen sharply recently, with the price of wheat hitting a two-year high last month after a severe drought and fires in Russia devastated crops there.

Undernourishment in 2010, by region (millions) Asia and the Pacific: 578

Sub-Saharan Africa: 239

Latin America and the Caribbean: 53

Near East and North Africa: 37

Developed countries: 19 Source: FAO

Higher wheat prices are also believed to have increased demand for other relatively cheaper foodstuffs, particularly other grains.

And higher grain prices are pushing up the price of meat and dairy products as the cost of feeding livestock increases.

The FAO also warns that the ability to achieve the international hunger targets in the Millennium Development Goals is at risk.

It says the total number of undernourished people is still higher than before the economic crisis of 2008-09.

The FAO says that analysing hunger during crisis and recovery "brings to the fore the insufficient resilience to economic shocks" of many poor countries.

"Lack of appropriate mechanisms to deal with the shocks or to protect the most vulnerable populations from their effects result in large swings in hunger following crises," the report says.

"Moreover, it should not be assumed that all the effects of crises on hunger disappear when the crisis is over."

Action Aid's head of policy Meredith Alexander said: "This is hardly time for celebration. Hunger is still no better than it was before the global food crisis and the goal to halve hunger is decades off track."

The FAO measure of undernourishment refers to an inadequate intake of calories. On average, this is considered to be less than 1,800 calories a day.

Action Aid uses the term malnutrition in a broad, not technical, sense, to cover both undernourishment (not enough calories) and also a nutritionally poor diet.