Food prices increased 4 percent in 2007 - the highest annual increase since 1990 - and they are expected to climb another 4 percent in 2008, according to the U.S. Department of Agriculture consumer price index.

In January, egg prices were 34.7 percent above the January 2007 level. Milk prices are 17.7 percent higher, beef is up 4.7 percent and fresh fruits up 6.6 percent, all from the previous year, according to the Department of Agriculture.

The surge in food prices is driven by across-the-board increases in raw product prices, like corn, and processing and transportation costs, said Julie Caswell, chairwoman of the Department of Resource Economics at the University of Massachusetts-Amherst.

Worldwide demand for corn is up because it's used in different foods and as a biofuel, she said. And hikes in commodities and gas prices have finally trickled down to affect the consumer's wallet.

Debra Wein, president of Sensible Nutrition Inc. in Hingham, said food shopping on a budget is a hot topic these days.

"This is a conversation we have often," Wein said. "You have to be really knowledgeable about prices. Just because it's a bargain on your wallet doesn't mean it's a bargain on your health."

Wein said she tells her clients to look for locally grown food, or buy frozen produce.

"The price of broccoli, for example, has skyrocketed because we're not growing it locally," she said. "Buying it frozen is a great way not to waste food and save money."

Caswell, the UMass economist, said there may be relief in sight. Lower demand or higher supply leads to lower prices, and farmers often react to price increases by producing more than consumers demand.

"Farmers do respond a lot to higher prices," Caswell said. "We're going into a planting season in the U.S. That industry reacts to higher prices. In fact, they have a history of overreacting."