World food prices remained stable in December from the month before as strong gains in vegetable oils and dairy largely offset falls in sugar and meat, the United Nations food agency said on Thursday. The Food and Agriculture Organization's (FAO) food price index, which measures monthly changes for a basket of cereals, oilseeds, dairy products, meat and sugar, averaged 171.8 points in December, versus 171.9 in November. Across the whole of 2016, the index fell 1.5 percent from the previous year, representing its fifth consecutive annual decline, FAO said.