As Foley notes, the recent upward movement in food prices follows decades of falling prices.
Those falling prices were the consequence of agricultural 'overproduction'.
('Overproduction' in capitalist terms, one understands, there was too much food relative to 'effective demand', i.e. incomes, not relative to actual need.)
European and American agricultural policy has been directed towards the problem of overproduction for a while. In 1993, and again in 2003 the EU adopted policies to stop subsidising overproduction, and start subsidising land retirement. The notorious 'set-aside' scheme paid farmers NOT to farm land. It was augmented with a 'wilderness scheme' which paid farmers to return their land to wilderness. The EU also gave subsidies to farmers 'diversifying' (i.e. getting out of farming). The US adopts similar land retirement schemes. The aim of all of these is to reduce output to stop prices going plunging.
(Clearly, first world governments are not going to disadvantage their own agricultural sector by letting African and Asian farmers supply the shortfall in their own output, so they have matched land retirement schemes at home with tariffs on third world imports.)
One sign of the land reduction policy is the extraordinary growth in the world's national parks. Of course area designated national park is often farmed, but its designation as national park is usually a sign that land has fallen into disuse and must be put under legal control. Between 1982 and 2003, 10 million square km of land was given over to national parks. Today national parks cover an area the size of China.
In an ideal world there would be nothing wrong with a rational reduction in food output to deal with overproduction - except there never was actual overproduction (only a shortage of spending cash in people's pockets) and monopoly control over prices would be bound to be bent to the advantage of big agri-business against small farmers.
The policy of a controlled limit on output, though, has gone too far. Rising incomes in the developing world are pulling in the opposite direction. With China's growing urban proletariat, we need more food not less. At that point the controlled reduction in food output becomes a direct attack on people's living standards.
My book, Green Capitalism: Manufacturing Scarcity in an Age of Abundance, develops these themes further http://www.amazon.com/GREEN-CAPITALISM-Manufacturing-scarcity-abundance/dp/1906496102/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1209290335&sr=8-2