Call it sticker shock.

Deborah Jourdan just can't stomach the menu at California Pizza Kitchen anymore. But the problem is not the price or the food. It's the calories.

"I looked at the menu, and it said there were 1,100 calories in a plate of pasta," the 22-year-old North Hollywood, Calif., resident said. Salads can run 1,400 calories or more. Pizza? Up to 1,500. That was earlier this year, and she hasn't been back since.

"I don't think I'd go back," said Jourdan, eating a salad and a cookie at Panera Bread in Burbank, Calif., "because I'd be afraid there would be nothing for me to eat."

It's a scenario that worries restaurateurs across the nation.

Many California restaurants have introduced calorie counts on menus in recent years. But as part of the recent federal health care overhaul, the Food and Drug Administration is expected to roll out national rules by year-end requiring any chain with 20 or more locations to post calorie counts for every item they sell.

Chains are scrambling to rework consumer favorites so they have fewer calories, and they are redesigning menus so that high-calorie items are balanced out by more healthful options.

IHOP took its bacon-and-eggs breakfast, with 1,160 calories, and developed a version with turkey bacon and egg whites that has just 350 calories. Panera Bread Co., worried that customers would balk at sandwiches with more than 1,000 calories, cut back on mayonnaise, salami and bread. Starbucks Corp. launched a line of tiny cakes and mini doughnuts.

"We're going into a new era," said Anita Jones-Mueller, a nutrition consultant who works with restaurants to slim down their menu offerings. "Never before have calories been on every chain restaurant menu in the United States. It's a game changer."

Companies that are the nimblest, responding quickly with retooled dishes or options for smaller portions, will fare the best, said Steve West, restaurant industry analyst for Stifel Nicolaus & Co. in St. Louis.

"People are going to find that they go to P.F. Chang's, and their orange chicken is 1,000 calories, and they're going to be looking for something to trade down to," he said. "That's going to be the big trade-down this year -- not money, calories."

Calorie counts are already required in some parts of the country, including California, New York City and Philadelphia. Californians may have noticed them come and go at some restaurants, because many counties -- including Los Angeles -- have put off enforcing the state rules until the release of the federal guidelines.

California Pizza Kitchen would not comment for this story, and a P.F. Chang's representative said the company was concentrating on ensuring its calorie counts were accurate.

Many in the industry say they don't expect most customers to cut back much once calorie counts are displayed nationwide.

But others say that's partly because there's no way to keep track of customers like Jourdan, who walk out the door, never to return.

At Real Mex Restaurants Inc., which owns El Torito, Acapulco and Chevys, officials knew ahead of time they might have what the industry is calling a sticker shock problem and worked hard to mitigate it, said marketing chief Lowell Petrie.

"We looked at everything we could to take out calories," Petrie said.

The company switched to lower-fat cheeses, started making some dishes with less oil and sauce and stopped plopping sour cream on every plate. New menus will highlight half-orders for salads and fajitas, Petrie said.