World Vision says it's forced to cut back on the number of people it will be able to help in the coming months, blaming a "perfect storm" of drought, changing food patterns and rising fuel costs.

The international aid organization is cutting back on the vital flow of food it can provide to the world's most impoverished -- saying it can no longer afford to feed 1.5 million of the 7.5 million people that received aid last year.

A confluence of factors has led to the cutbacks, according to Dave Toycen, president of World Vision Canada.

Toycen told CTV Newsnet that the cost of oil, has driven up the price of fertilizer. Furthermore, the production of biofuels is using up wheat and corn that would normally be used to feed people.

In Mexico, the soaring cost of flour has driven up the price of tortillas by 50 per cent.

Toycen said climate issues have compounded the situation, further driving up prices around the world.

"There's been a major drought in Australia," he said. "There's also changing food patterns in India and China, two countries with populations where they are now eating more meat and it takes more grain (to feed the animals) that would normally go to people."

Of the 1.5 million, 572,000 are children in urgent need of food to survive.

And the problem isn't expected to be short-lived. Toycen said he expects it will take two years for prices to stabilize and for World Vision to overcome the crisis.

The most profound result of the cutback, he said, is that hundreds of thousands of children under five, who rely on World Vision food to ensure their development, will not get the nutrition they need.

That can result in impaired brain development and stunted physical growth, which could have a devastating impact on economically challenged nations that desperately need a strong, healthy and educated future workforce, he said.

"The international community must ensure that preventing child hunger and malnutrition is the top priority in the search for a solution to the current food pricing crisis," Toycen said earlier in a news release.

World Vision is calling on countries and private donors to step up and fund the $500 million shortfall.

Toycen said that Canada has been a generous donor, but Canadians can urge their government to do more. He said tens of millions of people in refugee camps around the world are in dire need of emergency funding immediately. Toycen said it's in everyone's self interest to help.

"The more and more there's food instability and there's instability in the world, one way or another we seem to have repercussions," he said.

The organization is also asking countries that have pledged support, to make good on their promises.

World food shortage

The crisis faced by World Vision is one symptom of a global phenomenon that is being dubbed the "silent tsunami."

The United Nations World Food Programme warns that 20 million of the poorest children are at risk worldwide.

Josette Sheeran, the WFP's executive director, focused on the crisis Wednesday during a speech at a London summit dedicated to the subject.

She said the cost of rice has more than doubled in the last five weeks, and the World Bank estimates food prices have increased 83 per cent in three years.

Sheeran said the effects are being seen on all continents, and progress that has been made in the battle against poverty over the past five to 10 years could be lost if nations don't step up to meet the challenge.

British Prime Minister Gordon Brown is also involved in the summit. He said the effects of high food prices are being seen on all continents, and progress made in the battle against poverty over the past five to 10 years could be lost if nations don't step up to meet the challenge.

"Tackling hunger is a moral challenge to each of us and it is also a threat to the political and economic stability of nations," Brown said.

In the U.S., there are reports that Wal-Mart has limited the sale of rice to four bags per customer per day, over fears the supply will dry up.

With a report by CTV's John Vennavally-Rao