World food prices were flat again in December, though volatility in different sectors was on the rise, with increases in dairy products and meat balancing out drops in worldwide process for rice and other cereals, sugars, and oils and fats, according to the United Nations Food and Agriculture Organization (FAO) Thursday.

For 2013 as a whole, the overall index averaged 209.9 points, 1.6 percent lower than the average in 2012 and well below the 2011 peak of 230.1 points. The year was marked by increased stability in most components of the index.

For the year, an increase in supplies pushed grain prices lower, though rice prices fell less than corn and wheat. Dairy and meat prices hit all-time highs in 2013.

For December, strong harvests helped push cereal prices 2.8 percent lower than in November, to its lowest level in more than three years.

Sugar prices, a minor component in the overall index, slid dramatically in December, around 5 percent lower than in November, it's third consecutive monthly decline. The main factors were strong harvests in China and Thailand.

But dairy and meat prices rose for the month. Dairy products saw prices climb based on strong demand for powdered milk from China, forcing southern hemisphere milk producers to increase powdered milk production, resulting in a spike in prices for butter and cheese. Rusing demand in China dn Japan was also responsible for a small gain in meat prices, especially beef and pork.

Fats and oils saw prices fall slightly in December,

FAO's World Food Outlook is based on a basket of 55 goods and 73 price quotations in five major food commodity groups.

The next installment of the FAO World Food Price Index will be released Feb. 6.