The worst case of food inflation in nearly 20 years has more Americans giving up restaurant meals. We are buying fewer luxury food items, eating more leftovers, and buying more store brands instead of name-brand items.

For Peggy and David Valdez of Houston, feeding their family of four means scouring grocery ads for the best prices, taking fewer trips as a way to save gas, and simply buying less food - period.

"We do more selecting, looking around, seeing which prices are cheaper," said David Valdez. "We are being more selective. We have got to find the cheapest price."

Record-high energy, corn and wheat prices in the last year have led to sticker shock in grocery aisles.

Ground beef, milk, chicken, apples, tomatoes, lettuce, coffee and orange juice are among the staples that cost more these days, according to the federal Bureau of Labor Statistics.

Overall, food prices rose nearly 5 percent in 2007, according to the U.S. Department of Agriculture.

"The economy is having a definite impact on shopper behavior," said Tim Hammonds, president and chief executive officer of the Food Marketing Institute, a retail trade group. "People are significantly changing what they do."

Wal-Mart Stores Inc. and other supercenters that sell food now account for 24 percent of the market, according to the most recent annual survey of shopping habits by Hammonds' organization.

Gina Pierson, a music teacher in Columbia, Mo., and her husband, a public school teacher, are adjusting their approach to buying, cooking and eating food. Restaurant meals are almost a luxury.

"Between food and gas, it's just cheaper to stay home," she said.

In 2007, the marketing institute's survey showed the average number of weekly shopping trips falling below two per household for the first time.

Paula Curtis, a mental-health worker in Montpelier, Vt., said her grocery bill had been steadily climbing by $10 to $20 a week. She has cut back on meat, fruit, vegetables and snacks, and buys milk at the gas station, where she said it was cheaper.

"Every time I go, it's more and more," she said. "I make a list, but I don't necessarily get everything on it because I can't afford everything."

Nationwide, a family of four on a moderate-cost shopping plan now spends an average of $904 monthly for groceries, an $80 increase from two years ago, according to the Agriculture Department.

Those who cannot absorb the added expenses are increasingly seeking help from food pantries. America's Harvest, which distributes nearly 2 billion pounds of food and grocery products each year to more than 200 food banks across the country, estimates its overall client load increased 20 percent in the fourth quarter of 2007.

Shary Auer visits the Central Missouri Food Bank in Columbia once a month to help extend the family's $800 monthly food budget. The mother of five children, age 9 to 19, is buying more canned food instead of fresh produce. Portions are smaller around the Auer dinner table, and salads are added regularly to stretch the servings of meat and poultry.

"I watch for sales, save my receipts, and highlight what I save," she said.

Not all shoppers are struggling with the changes. At the Whole Foods Market in downtown Seattle, Beth Miller did not think twice about paying $6.39 for a gallon of organic orange juice, or $4 for a dozen eggs at the store, which specializes in organic and natural foods.

"I'm used to having a small gasp at the cash register," said Miller, who favors local produce and organic food for her husband and 12-year-old son. "We try to be really careful about what we eat."

Among retailers, the surge in commodity prices - from corn, now in high demand because of increased ethanol production, to wheat, which has tripled in price over the last 10 months - has some industry observers suggesting that higher food prices are not a temporary fluctuation but instead may be here to stay.