Cheaper energy kept U.S. consumer prices in check last month, the government said Tuesday, despite a big rise in the cost of food.The Labor Department reported that the consumer price index rose just 0.1 percent in February, matching January's increase. In the past 12 months, prices have risen just 1.1 percent, down from 1.6 percent in January and the smallest in five months.Excluding the volatile food and energy categories, core prices rose 0.1 percent last month and 1.6 percent in the past year. Energy prices fell 0.5 percent because gas and electricity costs fell. Clothes and used cars were also cheaper last month.Still, consumers took a hit at the grocery store as food costs rose 0.4 percent, the most in almost two-and-a-half years.