Consumers paid more for food and gas last month, although inflation outside those volatile categories was tame.
The Labor Department said Wednesday that the Consumer Price Index rose 0.3 percent in September, below a 0.4 percent rise in August. Excluding food and energy, so-called core prices increased 0.1 percent, the smallest rise since March.
Inflation has worsened this year, after the cost of oil, grains and other commodities spiked in the spring. But economists expect price increases to moderate as weak growth lowers commodity prices.
Food prices rose 0.4 percent, pushed up by big increases in the dairy, cereals, and fruits and vegetables categories. Gas prices rose 2.9 percent, driving up energy costs 2 percent. Clothing prices fell sharply.