'Tis the season for pricey salad greens and heirloom tomatoes at the local farmers' market. But even for those who don't run with the foodie set, produce prices have been growing quickly during recent decades, according to data from the Federal Reserve. Meanwhile, less healthy foods like sweets have remained relatively cheap. Together, the two trends are contributing to a fast-growing obesity rate, experts say.
While food prices are growing, they have not diverged much from the broader rate of inflation, according to Fed data. The consumer price index, or CPI, for food has remained close to the CPI for all items since the late 40s, according to Fed data. - US News and World Report
(Granted, the CPI for all items includes food, so any big swings in food prices would shift the CPI as well.)