The linked article is a bit alarmist in its tone, although the basic data it's built on is pretty much on target. However, for a more cogent and reasoned look at the issue I recommend a read of this brief from the 6 Dec 07 issue of The Economist:

Food Prices: Cheap No More
....According to the World Bank, 3 billion people live in rural areas in developing countries, of whom 2.5 billion are involved in farming. That 3 billion includes three-quarters of the world's poorest people. So in principle the poor overall should gain from higher farm incomes. In practice many will not. There are large numbers of people who lose more from higher food bills than they gain from higher farm incomes. Exactly how many varies widely from place to place.

Among the losers from higher food prices are big importers. Japan, Mexico and Saudi Arabia will have to spend more to buy their food. Perhaps they can afford it. More worryingly, some of the poorest places in Asia (Bangladesh and Nepal) and Africa (Benin and Niger) also face higher food bills. Developing countries as a whole will spend over $50 billion importing cereals this year, 10% more than last.

Rising prices will also hurt the most vulnerable of all. The World Food Programme, the main provider of emergency food aid, says the cost of its operations has increased by more than half in the past five years and will rise by another third in the next two. Food-aid flows have fallen to their lowest level since 1973.

In every country, the least well-off consumers are hardest hit when food prices rise. This is true in rich and poor countries alike but the scale in the latter is altogether different. As Gary Becker, a Nobel economics laureate at the University of Chicago, points out, if food prices rise by one-third, they will reduce living standards in rich countries by about 3%, but in very poor ones by over 20%.

Not all consumers in poor countries are equally vulnerable. The food of the poor in the Andes, for example, is potatoes; in Ethiopia, teff: neither is traded much across borders, so producers and consumers are less affected by rising world prices. As the World Bank's annual World Development Report shows, the number of urban consumers varies from over half the total number of poor in Bolivia, to about a quarter in Zambia and Ethiopia, to less than a tenth in Vietnam and Cambodia.

But overall, enormous numbers of the poor—both urban and landless labourers—are net buyers of food, not net sellers. They have already been hard hit: witness the riots that took place in Mexico over tortilla prices earlier this year. According to IFPRI, the expansion of ethanol and other biofuels could reduce calorie intake by another 4-8% in Africa and 2-5% in Asia by 2020. For some countries, such as Afghanistan and Nigeria, which are only just above subsistence levels, such a fall in living standards could be catastrophic.....