WASHINGTON (AP) — U.S. consumer prices rose slightly last month,as higher energy costs partly offset cheaper food. The smallincrease is further evidence that consumers are benefiting frommild inflation.

The consumer price index ticked up a seasonally adjusted 0.1percent in May from April, the Labor Department said Tuesday. Overthe past 12 months, prices have risen just 1.4 percent.

Excluding volatile food and gas costs, core prices rose 0.2percent in May from April. Core prices are up just 1.7 percent overthe past 12 months, in line with the Federal Reserve's inflationtarget of 2 percent.

"Inflation has faded to only a minor irritant," MichaelMontgomery, an economist at IHS Global Insight, said in a note toclients.

Slow economic growth and high unemployment have kept wages fromrising quickly. That's made it harder for retailers and other firmsto raise prices.

Tame inflation has helped consumers increase spending this year,despite slow income growth and higher Social Security taxes. Italso makes it easier for the Fed to continue its extraordinaryefforts to boost the economy.

The Fed is meeting Tuesday and Wednesday amid growingspeculation that policymakers could soon scale back$85-billion-a-month in bond purchases. The bond buys are intendedto lower long-term interest rates and encourage more borrowing,investing and spending.

If inflation were to fall too low, the Fed might be inclined toavoid pulling back on its stimulus. But economists said the smallgain in prices last month isn't low enough to alarm Fedpolicymakers.

Tuesday's report "won't prevent the Fed from beginning to reduceits monthly asset purchases, probably beginning in September," saidPaul Ashworth, an economist at Capital Economics.

In May, higher natural gas and electricity costs pushed upenergy prices 0.4 percent. Gas prices were flat. Food costs fell0.1 percent, as grocery prices dropped by the most in almost fouryears.

The cost for prescription and nonprescription drugs fell 0.7percent in May, the steepest decline on record. The cost formedical services was unchanged last month.

Overall health care prices rose just 2.2 percent since May 2012.That's the smallest year-over-year increase for that category inmore than 40 years, helping keep inflation mild.

Consumers have kept spending at a modest pace in recent months.Retail sales rose at a healthy clip in May from April, the CommerceDepartment said last week. Americans spent more on cars and trucks,home improvements and sporting goods.

Steady job gains and resilient consumer spending have fueledintense speculation that the Fed may soon start reducing the paceof its monthly bond purchases. That's caused heavy volatility instock and bond prices.

The Fed has said it will continue to buy bonds until the jobmarket improves substantially.

The Fed also says it plans to keep the short-term interest rateit controls at a record low near zero until the unemployment ratefalls below 6.5 percent, provided inflation remains under control.The unemployment rate ticked up in May to 7.6 percent, though it isdown 0.6 percentage points in the past year.