Reuters: World food prices are rising faster than they have for more than 30 years, putting hundreds of millions of vulnerable people at increased risk of hunger and malnutrition, food experts warn. "The world food system is in trouble. The situation has not been this much concern for 15 years", Joachim von Braun, head of the International Food Policy Research Institute (IFPRI), cautions in Christian Science Monitor. The end of the cheap food era is likely to see more people …