WASHINGTON: US producer prices edged up slightly in January as the biggest rise in food costs in eight months offset a further decline in energy prices. The tiny overall increase indicated that inflation pressures remain modest. The Labour Department said on Wednesday that its Producer Price Index rose 0.1 per cent in January after having fallen 0.2 per cent in December. Over the past year, the PPI, which measures inflation pressures before they reach the consumer, is down 0.2 per cent. Core inflation, which excludes energy and food, rose 0.4 per cent in January, the biggest one-month jump in 15 months. Over the past 12 months, core inflation is up 0.6 per cent.