By CHRISTOPHER S. RUGABERWASHINGTON (AP) a¿¿ U.S. consumer prices increased only slightly in September, as higher energy costs offset flat food prices. The figures are the latest evidence that slow economic growth is keeping inflation tame. The consumer price index rose a seasonally adjusted 0.2 percent in September, the Labor Department said Wednesday. That's up from 0.1 percent in August. Higher gas, electricity and other energy costs rose 0.8 percent, making up about half the overall increase. In the past year, consumer prices have increased just 1.2 percent, down from a 1.5 percent annual gain in August. That's the smallest 12-month gain since April, and it's below the Federal Reserve's 2 percent inflation target. Excluding volatile food and energy costs, core prices rose just 0.1 percent and are up 1.7 percent in the past 12 months. High unemployment and meager wage increases have made it difficult for Americans to pay more for most goods. That has also made it hard for retailers to charge more. With inflation below the Fed's target, the central bank faces less pressure to scale back its $85 billion-a-month in bond purchases. The bond purchases are intended to keep long-term inflation rates low and stimulate economic growth. But critics fear it raises the risk of higher inflation. Extremely low inflation may even increase pressure on the Fed to extend the purchases. Some Fed officials have objected to slowing the bond-buying program when inflation is well below 2 percent. A small amount of inflation can be good for the economy because it encourages consumers and businesses to spend and invest before prices rise further. Fed policymakers will conclude a two-day meeting Wednesday. Economists expect the Fed won't make any changes to its current policies, which include keeping a key short-term interest rate near zero. Paul Dales, an economist at Capital Economics, says price gains have picked up in the past few months, a sign "the Fed needn't worry too much about low inflation."