Quote from the article:
"Roughly a billion people live on $1 a day. If, on a conservative estimate, the cost of their food rises 20% (and in some places, it has risen a lot more), 100m people could be forced back to this level, the common measure of absolute poverty. In some countries, that would undo all the gains in poverty reduction they have made during the past decade of growth."A related article, specific to Bangledesh.
"The new face of hunger," a longer article about the economics of the situation.