Workers sweep around sacks of grain at a UN World Food Programme warehouse in Port-au-Prince, Haiti, where some aid organizations are warning of a widening nutritional crisis. Spiralling food prices have sparked protests and led to the ouster of the nation's No. 2 politician. (Brennan Linsley/Associated Press)

World Vision says soaring food costs will force it to cut 1.5 million people from the roster of 7.5 million it fed last year, one-third of them children who rely on the organization's aid to survive.

"The hungry are resourceful, they'll do what they have to, but it's going to take human life, there's no question about that," World Vision Canada president Dave Toycen told CBC News on Wednesday.

About 572,000 of those who will not receive food support are children who depend on that nourishment to thrive, Toycen said. While children funded by World Vision's sponsor-parent program will continue to receive aid, he said they could still be affected by an overall food shortage in their community.

"Well, at this point [people will] do like the hungry always do.… If they were getting two meals a day, now they'll cut back to one meal a day or, in some cases, they won't eat every day."

The rising cost of oil and fertilizer, more fields being used to produce corn for ethanol, drought in Australia and changing food consumption patterns have all contributed to the current crisis, Toycen said.

He also blamed donor countries for not living up their aid commitments, although he excused Canada by saying it was fairly consistent in delivering about $100 million each year.

One of the world's largest humanitarian organizations, World Vision provides food aid in 35 countries. The organization is calling on governments to collectively contribute $500 million to cover a shortfall in the United Nation's World Food Programme, one of World Vision's largest sources of food aid.

Toycen estimated it would take a few million dollars for his organization to respond to inflated food prices, which he doesn't expect to stabilize for at least another two years.

The soaring cost of food is poised to unleash a "silent tsunami" of hunger around the world, the head of the World Food Programme said Tuesday. The World Bank has estimated the crisis could drive 100 million people deeper into poverty.

"This is the new face of hunger — the millions of people who were not in the urgent hunger category six months ago but now are," World Food Programme chief Josette Sheeran said.

Unrest over the food crisis has led to deaths in Cameroon and Haiti, costing Haitian Prime Minister Jacques Edouard Alexis his job, and has caused hungry textile workers to clash with police in Bangladesh.

Former UN secretary general Kofi Annan has predicted more protests in other developing nations if the problem remains unchecked.

With files from the Canadian Press