A doubling of food prices over the past three years could push 100 million people in poorer developing countries further into poverty and governments must step in to tackle the issue, World Bank president Robert Zoellick said on Sunday. "Based on a rough analysis, we estimate that a doubling of food prices over the last three years could potentially push 100 million people in low-incomecountries deeper into poverty," Zoellick said in a statement at the end of the World Bank spring meeting here.