Chain restaurants in the United States are promoting dangerous "X-treme Eating", a US watchdog has said.
People who eat out are more likely to consume more, research says
They are serving up "ever-more harmful new creations," the Center for Science in the Public Interest says.
It says that some individual dishes can exceed 2,000 calories, more than the recommended daily intake for women.
As more than one in five US adults are obese, it says restaurants should list nutritional information on their menus to make consumers more aware.
Some 60 million adults in the US are obese, according to the American Obesity Association, which says that obesity is not a simple matter of overeating.
But the CSPI said many restaurants are doing little to alleviate the problem.
"Rather than compete to make their products healthier, restaurant chains are competing with each other to make their appetizers, main courses, and desserts bigger, badder, and cheesier than ever before," a CSPI statement said.
"Burgers, pizzas, and quesadillas were never health foods to begin with," CSPI executive director Michael Jacobson said.
"Now we see lasagne with meatballs on top; ice cream with cookies, brownies, and candy mixed in; bacon cheeseburger pizzas, buffalo-chicken-stuffed quesadillas, and other hybrid horribles that are seemingly designed to promote obesity, heart disease, and stroke."
Huge calorie counts
Some American restaurant chains have menus that contain 2,000-calorie appetizers, 2,000-calorie main courses and 1,700 calorie desserts.
The health watchdog points its finger at chains such as Ruby Tuesday, Uno Chicago Grill and the Cheesecake Factory.
More than one in five US adults is obese, experts say
The latter's Chris' Outrageous Chocolate Cake combines brownie, pie, and cheesecake into 1,380-calorie pudding.
The CSPI says this is "the equivalent of eating two [McDonald's] Quarter Pounders plus a large fries - for dessert".
"Since those chains make almost zero nutrition information available on menus, their customers don't have a clue that they might be getting a whole day's worth of calories in a single dish, or several days' worth in the whole meal," the centre says.
CSPI nutrition policy director Margo Wootan said that Americans eat out for an average of four meals a week.
She said studies show that women who eat out more than five times a week eat an average of 300 more calories per day than women who eat out less often.
"With dishes like these, it's easy blow your diet not just for the day but for the whole week," Mrs Wootan said.
But Frank Guidara, the president and CEO of Uno's, said the CSPI study was flawed.
One Uno's item the group criticised was meant to be shared by five people, he said.
"Our menu is as healthy as any menu out there. We have some indulgent items but so what?," he asked.
And he said the company made nutrition information available at computer kiosks in every restaurant lobby.
Ruby Tuesday spokesman Rick Johnson argued that there was not necessarily a connection between food labelling and health.
"The rate of obesity has not gone down - but has gone up since food labelling was introduced many years ago," he said.
"So you have to be careful of the conclusion that food labelling means people will eat more healthy foods."