Sometimes, American restaurants unveil menu items that are so gluttonous that they seem to be trying to stun the senses. This was the case earlier this year with KFC's much-discussed Double Down sandwich: two pieces of bacon, two slices of cheese and "Colonel's Sauce," with two thick filets of fried chicken functioning as the bun.

But compared with some chain restaurants' offerings, the 540-calorie Double Down is almost health food. Many meals offered at these eateries are much worse, nutritionally speaking.

Below is a list of dishes that in just one sitting provide close to or more than the 2,000 calories recommended by the U.S. Department of Agriculture for an entire day's sustenance. They also mostly stomp all over the recommended daily intakes for sodium (no more than 2,400 milligrams), fat (65 grams) and saturated fat (20 grams) for someone on a 2,000-calorie diet.

"These chains don't promote moderation," Michael F. Jacobson, the executive director of the Center for Science in the Public Interest, said in May, when his watchdog organization gave its 2010 Xtreme Eating awards to nine "caloric heavyweight" meals. "They practice caloric extremism, and they're helping make modern-day Americans become the most obese people ever to walk the Earth."

Jacobson also expressed surprise that restaurants haven't started to alter their menus in advance of a new law that will require chains with 20 or more outlets to disclose calorie counts to diners. (The Food and Drug Administration hasn't specified when the regulations will take effect.)

"Restaurants are not in the business of making people healthy," says Washington dietitian Rebecca Scritchfield. "They're trying to make money, and salt and fat are cheap ways to make food taste better."

We asked Scritchfield to give us her take on these caloric heavyweights.

All of the nutritional information below comes from the restaurants' Web sites, except for the Cheesecake Factory's, which is courtesy of CSPI's Xtreme Eating awards. (The chain does not publish its nutritional information online.)

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-- Quiznos large tuna melt sub sandwich.

The numbers: 1,520 calories, 101 grams of fat, 21 grams of saturated fat, 2,020 milligrams sodium.

Equivalent of eating: More than a stick of butter's worth of fat.

Expert evaluation: Grabbing a tuna sandwich for lunch sure sounds like a healthful decision, but not with this jumbo-size sub. "If someone hears 'tuna' and they think they should be eating more fish, they might think that's a good choice, but the portion is way too big," Scritchfield says. On top of that, "it's made with foods that have high calories, such as mayonnaise and cheese."

-- Chipotle's chicken burrito, filled with rice, pinto beans, corn salsa, cheese, sour cream and guacamole, accompanied by a side of chips.

The numbers: 1,750 calories, 79.5 grams of fat, 23 grams of saturated fat, 2,750 milligrams of sodium.

Equivalent of eating: The calories in more than nine chicken soft tacos at Taco Bell.

Expert evaluation: "There are lots of ways you can make that healthier," Scritchfield says. "My top recommendation is not to get cheese and sour cream but instead get guacamole because that has the heart-healthy fat and gives you the creaminess you're going for." You could also forgo the chips and save 570 calories.

-- Applebee's New England fish and chips.

The numbers: 1,910 calories, 137 grams fat, 24 grams saturated fat, 3,150 milligrams of sodium.

Equivalent of eating: The fat in almost a pound of cheddar cheese.

Expert evaluation: "If you really wanted this, I'd say split it and add some veggies," Scritchfield says. "And do not touch the salt shaker; it already has more than a day's worth of sodium in it."

-- Chili's Big Mouth Bites, four mini burgers topped with jalapeño ranch dressing.

The numbers: 1,930 calories, 31 grams of saturated fat, 4,400 milligrams sodium.

Equivalent of eating: The calories of around 25 eggs.

Expert evaluation: "These are interesting because they're sold as 'mini' burgers, but it's still a high-calorie, high-fat and high-salt meal because of what's on them," Scritchfield says.

-- Outback Steakhouse's full rack of baby back ribs served with Aussie fries.

The numbers: 1,936 calories, 133 grams of fat, 56 grams of saturated fat, 2,741 milligrams of sodium.

Equivalent of eating: The fat grams in 20 tablespoons of salad dressing.

Expert evaluation: "There is no color on that plate: no broccoli, no garden salad. Vegetables should be half of your dinner plate, and they're absent," Scritchfield says. Outback diners can substitute steamed green beans or seasonal veggies for the fries and slash about 200 calories and 15 grams of fat.

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The mega-meals below could be shared, but Scritchfield says it wouldn't be surprising if they sometimes are consumed by just one person: "People envision what they're served as their portion."

-- Domino's bread bowl pasta.

The numbers: One bread bowl, which Domino's nutritional information counts as two servings, contains 1,340 to 1,470 calories, 48 to 56 grams of fat, 21 to 27 grams of saturated fat, 65 to 115 grams of fiber, 1,830 to 2,860 milligrams of sodium.

Equivalent of eating: The fiber in about 16 to 29 servings of oatmeal.

Expert evaluation: "If you get enough fiber, and 25 to 35 grams a day is the right amount, it helps keep digestion at a normal pace. But if you eat too much fiber, it actually gives you constipation," Scritchfield says.

-- P.F. Chang's China Bistro's double pan-fried noodles with a combination of meats. Although this is one entree, the company count it as four servings since it totals 36 ounces.

The numbers: 1,820 calories, 84 grams of fat, 8 grams saturated fat, 7,692 milligrams of sodium.

Equivalent of eating: The sodium in 70 tablespoons of blue cheese dressing.

Expert evaluation: "If four people shared this [as their entire meal], not only would the waiter be like, 'What are you doing?' but we'd leave dissatisfied," Scritchfield says. "They're breaking it down so their numbers look good."

-- The Greene Turtle's boneless wings, which includes 16 wings in "We Mean Hot" sauce, served with blue cheese dressing and celery sticks.

The numbers: 1,963 calories, 153 grams of fat, 30 grams of saturated fat, 10,877 milligrams of sodium.

Equivalent of eating: The sodium in 52 large orders of french fries.

Expert evaluation: "I thought there was a typo, that there's no way that has 10,000 milligrams of sodium, but sure enough, they do," Scritchfield says. "Salt is a flavor enhancer, but this amount is unnecessarily over the top." An order of 16 regular wings with "Kinda Hot" sauce contains 1,787 calories and drops the sodium intake to 6,819 grams.

-- Uno Chicago Grill's Chicago Classic deep-dish individual pizza, which is topped with sausage, tomato sauce and cheese.

The numbers: 2,310 calories, 165 grams of fat, 54 grams saturated fat, 4,920 milligrams of sodium.

Equivalent of eating: The fat in 45 strips of bacon.

Expert evaluation: Although Uno counts this smaller pizza as having three servings in its online nutritional information, Scritchfield says that when someone orders an "individual" pizza, they are likely to see it as a meal for one.

-- The Cheesecake Factory's pasta carbonara.

The numbers: 2,500 calories, 85 grams of saturated fat.

Equivalent of eating: The saturated fat in about five cups of half-and-half cream.

Expert evaluation: "Four adult men would have to share this entree in order to each stay within a day's worth of saturated fat," says Scritchfield.