U.S. food prices are set to rise as much as 4 percent this year, the biggest increase in 14 years, due to higher prices for beef, milk and fresh vegetables, according to USDA.

"It looks like we're going to end up between 3.5 and 4 percent higher," says Ephraim Leibtag, an economist with USDA's Economic Research Service. In comparison to other years, food prices increased by 2.2 percent in 2003 and 1.8 percent in 2002.

A big factor in this year's food price increase is beef, which soared by as much as 11 percent, due partly to consumers adopting low carbohydrate and high protein diets.

U.S. consumers also are paying higher prices for pork products. Fourth-quarter retail pork prices are expected to continue to average in the high $2.80s per pound, about 7 percent above a year ago, according to USDA. But when compared with beef prices, pork is still a much better buy.

Milk, dairy products, and eggs rose by as much as 8 percent. The price of fresh vegetables rose by as much as 4 percent in 2004 because of a string of hurricanes and torrential downpours that hit Florida and California.

"It looks like we're going to be the highest since 1990" in terms of overall food price inflation, says Leibtag.            

Another factor affecting food prices, USDA says, is record-high gasoline and diesel fuel used to transport goods to market.