Regular restaurant-goers could be tucking away many more calories than they realize when they go out to eat, a consumer advocacy group reported Monday.

In an article in the March issue of the Center for Science in the Public Interest's Nutrition Action Healthletter, the group says consumers may be unaware of the massive calorie counts of many appetizers, entrees and desserts at popular restaurants, since this information is not presented on the menu.

And they say the problem is getting worse.

Jayne Hurley, senior nutritionist at the Center for Science in the Public Interest and author of the article, says that when she first started studying the caloric content of restaurant foods, the numbers were already frightening; 1,000-calorie appetizers, entrees and desserts were common.

Now, however, she says that it is not unusual to find appetizers and entrees containing 2,000 calories apiece, topped off with a 1,500-calorie dessert.

"The numbers just keep on climbing, and because the information is not on the menu, the restaurants don't clue people in."

But the restaurant industry says the article is misleading. In a press statement issued Monday, the National Restaurant Association, which is composed of 935,000 restaurants and food service outlets nationwide, called the report "outrageous."

"Pointing to a select few menu items at a select few restaurants as being high in calories and generalizing that to all restaurant fare is misleading, inaccurate and does the public a grave disservice," the statement reads.

As American as 1,500-Calorie Apple Pie

The article strikes to the heart of an activity that has become a national pastime for many Americans, who typically go out to eat about four times a week.

This affinity for restaurant dining could be one of the reasons for ever-expanding waistlines in the country.

"The big problem here is that people are eating out in record numbers," Hurley says. "On average, people get one-third of their calories in restaurants, so in a way, restaurants deserve part of the blame for the country's obesity problem."

As opposed to earlier decades, when restaurant visits may have been a once-in-a-while luxury, Hurley says, many families are now eating several meals per week at restaurants.

But eating out by itself may not be the only problem. Hurley says menu offerings are becoming more calorie laden than ever before. And she says a slowdown of this trend does not appear to be on the horizon.

"People are not going to be eating out less in the future. They're going to be eating out more. And as the number of calories in what they eat gets bigger and bigger, people are also going to be getting bigger and bigger."

Diet experts say the trend toward more calories per plate is a disturbing one.

"No question about it, these are high-calorie dishes," says Keith Ayoob, associate professor in the department of pediatrics at Albert Einstein College of Medicine in New York.

"Once in a great while, it's probably OK, but if people are eating these foods regularly, that's a whole different game."

Part of the problem is that consumers may be mostly value-conscious when they eat out.

"Restaurant menus have tried to achieve a 'more for your money' and a 'better than the next guy' philosophy, and right now that often means more food," says Connie Diekman, director of university nutrition at Washington University in St. Louis.

"Larger restaurant portions are making it difficult for consumers to know what are appropriate portions, and it seems to be leading to a perception that these portions are the norm."

Call for Menu Nutritional Information

One of the chief recommendations in the CSPI article is for restaurants to include calorie counts and other nutritional information on menus and menu boards.

Such measures will likely be put in place in many chain restaurants in New York City this summer, following a move by the New York City Board of Health.

And that decision by New York could have a domino effect on other places around the country.

"Once the information is on menus in one city, companies may not want to be thought of as providing this information to one city and not others," Ayoob says.

But the move would not be one that would be welcomed by restaurant groups.

"Posting caloric and other nutritional information on menus and menu boards would make those menus extremely cluttered, confusing and simply not helpful to those who want to make smart choices when dining out," says the National Restaurant Association in its statement.

And even diet experts say additional information on menus will not be a cure-all.

"I just think about all the labeling on cigarette packs," Ayoob says. "After a while, people just didn't pay much attention."

Responsible Consumer Choices Important

Ayoob says it is little surprise that restaurants are offering more food for their money to consumers.

"They're in the people-pleasing business, and people like to see a full plate," he says. "Try and get this food without plunking down the right amount of cash. It won't happen."

So, in addition to calls for more nutritional information from restaurants, Diekman says it is equally important for consumers to take responsibility for their own health by controlling what they eat -- as well as how much they eat.

"Restaurants are in the business of meeting customers' wants, and if these choices are popular they will appear on menus," she says. "Education of consumers on healthier choices needs to occur simultaneously with restaurant change -- one can't succeed without the other."