Adults, on average, should be consuming between 1,600 and 2,400 calories a day, but some of these restaurant meals could shatter your daily allowance with one plate.

The Center for Science in the Public Interest, a Washington, D.C.-based food watchdog and consumer advocacy group, released its annual "Xtreme Eating Awards" Monday, a list they call the biggest "nutritional nightmares" in the restaurant industry.

The group tallied up calorie data from chain restaurants to determine the worst offenders. Each year, the list varies, but usually includes a variety of breakfast dishes, dinners, appetizers, desserts and beverages.

"These meals are extreme, but even the typical dishes served at restaurants are a threat to Americans' health because they increase the risk of obesity, diabetes, heart disease, and more," Lindsay Moyer, CSPI senior nutritionist, said in a statement.

That said, restaurants often note that it is up to consumers to make choices about what they eat and, even with an occasional indulgence, many can have a healthy overall diet. Also, some of the items on the list are made to be shared by more than one person.

"While we applaud the Center for Science in the Public Interest's efforts to educate Americans on making healthier food choices, it's misleading to single out the highest possible meal combinations without informing people about the wide range of choices offered at our restaurants, including the ability to customize any item on our menu to meet a variety of dietary needs," Stephanie Peterson, spokeswoman for IHOP, told CNBC.

Here's a look at CSPI's list of dishes with the highest calorie counts.