Sonic, according to a 24/7 Wall St. analysis, is the least healthy major fast-food restaurant in the United States.

24/7 Wall St. analyzed nutritional information for each of the country’s largest fast-food restaurants based on publicly available nutritional information for each chains menu. Specifically, we examined the levels of saturated fat, trans fat, sodium, carbohydrates, sugars, and calories in each menu item and compared them to the typical levels found at the nation’s most popular fast-food chains. More menu items exceeding those levels resulted in a lower rank. Based on our rank, these are the least healthy fast-food restaurants in the country.

Click here to see America’s least healthy fast-food chains.

We chose these six nutrient components because nutrition experts widely agree that high consumption of these nutrients — above the recommended values — is unhealthy. These nutrient components are also among the most likely to appear in unhealthy amounts on America’s fast-food menus.

Christine Palumbo, RDN, FAND, a nationally recognized nutrition expert, discussed the problems with some of the worst fast-food menu items. “When I think of extremely unhealthful fast-food items, they tend to be large, meat-heavy sandwiches,” Palumbo said. “They are high in calories, sodium, and saturated fat.” Those are the nutrients that are linked to cardiovascular disease, she said. In fact, seven of the ten least healthy restaurants identified by 24/7 Wall St. primarily served hamburgers.

However, it is possible to both eat at fast-food chains, and maintain a healthy lifestyle. “I would not ever want to dissuade someone from eating at a Wendy’s, a Taco Bell, a KFC, a McDonald’s, or Chick-Fil-A,” Palumbo added. “You can eat well, you can eat very, very poorly, or somewhere in between. It all boils down to the choices you’re going to make.”

Indeed, when we conducted our review of the largest fast-food restaurants, we wanted to acknowledge that consumers have a choice to avoid the worst items on the menu. In order to account for this, 24/7 Wall St. penalized restaurants based on the extent to which the menu is unhealthy as a whole, rather than on the most egregious item on the menu.

For example, Popeye’s Chicken Livers sandwich, which has nearly 1,200 calories, 34 grams of saturated fat, and 4.5 grams of trans fat, is one of the least healthy items on any fast-food menu. Yet no other meal item on Popeye’s menu has more than 690 calories or 22 grams of saturated fat. Popeye’s, therefore, did not rank as one of the least healthy restaurants because it offers many healthier options. Restaurants that offered many unhealthy options and few healthier ones ranked lower.

Speaking with 24/7 Wall St., Jim White, RDN, ACSM HFS, spokesman for the Academy of Nutrition & Dietetics, and owner of Jim White Fitness & Nutrition Studios, explained how difficult it can be for Americans to determine what is healthy on their menus. “You could have a meal that is fairly low in fat, and most people would think it is healthy.” However, he said, all nutritional measures should be considered. “It’s really hard for the consumer, because it’s a balance. Most measure calories, or fat or carbs, but looking at all of them is important to get the equal value for these items.”

Toby Amidor, dietitian-nutritionist and author of “The Greek Yogurt Kitchen: More Than 130 Delicious, Healthy Recipes for Every Meal of the Day,” explained that poor health consequences occur when popular restaurants have items that exceed daily recommended levels in more than one category. Indeed, the least healthy fast-food restaurants have items above the recommended levels of multiple nutrients. In the case of Quizno’s, for example, more than 35% of the restaurant’s meal items had among the highest levels in all six categories. In many of the healthier restaurants, none of the meal items were above normal levels in all six nutrients we considered.

Click here to read our full methodology.

These are America’s least healthy fast-food chains.

10. Burger King
>Pct. meals with 600+ calories: 25.5%
>Pct. meals with 10+ g saturated fat: 29.6%
>Pct. meals with 1,000+ mg sodium: 49.0%
>Pct. meals unhealthy in at least one nutrition category: 72.4%

While it is considered the chief competitor to McDonald’s, Burger King lags far behind the golden arches in sales, with just $8.5 billion in the United States compared to McDonald’s $35.8 billion U.S. sales. Burger King also lags behind McDonald’s in terms of the health of its menu. The Ultimate Breakfast Platter, for example, has 1,420 calories — nearly three-quarters of a full day’s diet for the average adult, as well as 139 grams of carbs, close to half the recommended daily intake. Despite the presence of several unhealthy breakfast items, Burger King’s main courses are roughly in line with McDonalds in our health ranking. However, while McDonald’s sides are the second healthiest, Burger King’s are the ninth healthiest. The large hash browns has 670 calories.

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9. Checkers
>Pct. meals with 600+ calories: 51.0%
>Pct. meals with 10+ g saturated fat: 75.5%
>Pct. meals with 1,000+ mg sodium: 69.4%
>Pct. meals unhealthy in at least one nutrition category: 91.8%

While not one of the top tier of popular fast-food restaurants, Checkers still has hundreds of locations around the country, and is among the 50 most popular fast-food chains in the country. It is is also one of the least healthy chains in the country. More than three-quarters of the meals on its menu have higher levels of saturated fat than in comparable menu items of other major fast-food restaurants. The Food and Drug Administration recommends that individuals limit their saturated fat consumption to 20 grams a day, and advises that more than 4 grams of saturated fat in a single meal is high. It is impossible to order anything from the burger menu at Checkers without at least doubling the amount of saturated fat the FDA deems reasonable for a meal. In fact, the ½ LB Double Champ with Cheese, contains 140% of the recommended total daily value of saturated fat. Adding an order of large french fries adds another 20 grams of saturated fat, a total just shy of two-and-a-half days’ worth in one meal.

8. Chick-fil-A
>Pct. meals with 600+ calories: 10.8%
>Pct. meals with 10+ g saturated fat: 18.9%
>Pct. meals with 1,000+ mg sodium: 56.8%
>Pct. meals unhealthy in at least one nutrition category: 75.7%

The Atlanta-based fast-food restaurant is famous for its chicken sandwiches as well as for being closed on Sundays. On the remaining six days of the week, the fast-food chain serves some of the least healthy food among the nation’s largest restaurants. Relative to many of the largest fast-food chains, Chick-fil-A’s main courses actually rank as among the healthiest. The Grilled Chicken Sandwich, for example, is healthier than the majority of fast-food meals for every nutrition category considered except for sodium. The restaurant’s sides, however, worsen its rating. Nearly 45% of Chick-fil-A’s sides have above-average sugar content among the menu items considered. The large coleslaw has 26 grams of sugar, higher than in all but four sides among the most popular fast-food restaurants in the country.

7. Wendy’s
>Pct. meals with 600+ calories: 20.0%
>Pct. meals with 10+ g saturated fat: 34.7%
>Pct. meals with 1,000+ mg sodium: 45.3%
>Pct. meals unhealthy in at least one nutrition category: 74.7%

With nearly 5,800 locations and $8.8 billion in sales in 2013, Wendy’s is one of America’s largest and most popular fast-food chains. It is also one of the least healthy. A Wendy’s Baconator hamburger sandwich has nearly half the recommended daily value of calories for the average adult and 115% of the daily recommended amount of saturated fat. While most consumers are not likely to choose the Baconator for its nutritional value, the lighter side of Wendy’s menu has its share of hidden dangers. At 350 calories the Apple Pecan Chicken Salad may seem like a healthy choice. However, with a total of 17 grams of sugar, it has more sugar than 90% of all menu items from the largest fast-food restaurants.

6. Jack in the Box
>Pct. meals with 600+ calories: 32.5%
>Pct. meals with 10+ g saturated fat: 40.3%
>Pct. meals with 1,000+ mg sodium: 62.3%
>Pct. meals unhealthy in at least one nutrition category: 74.0%

San Diego-based Jack in the Box currently satisfies Americans’ fast-food cravings in 21 states. From the hamburger menu, Jack In The Box has eight sandwiches that contain an individual’s entire recommended daily value of saturated fat. Though the menu is mostly unhealthy, the restaurant goes out of its way to provide options for the health conscious consumer. By sticking to the “Better For You” menu segment, patrons can avoid the least healthy menu items and have a higher likelihood — although not a guarantee — of choosing something low in calories, saturated fat, and sugar. While the “Better For You” designation can be a helpful guide, it is not accurate in every case. For example, the Chicken Teriyaki Bowl has nearly 700 calories and more carbohydrates and sugar than 98% of all the fast-food meals in all of the restaurants considered.

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5. Arby’s
>Pct. meals with 600+ calories: 18.2%
>Pct. meals with 10+ g saturated fat: 22.7%
>Pct. meals with 1,000+ mg sodium: 75.8%
>Pct. meals unhealthy in at least one nutrition category: 75.8%

Arby’s, an Atlanta-based chain, is known for its roast beef sandwiches. While not always the case, some of those sandwiches are very unhealthy. All but one sandwich have exceptionally unhealthy proportions of at least two of the six nutrition categories, and half of the sandwiches have among the worst levels of four or five of the six categories. A third of Arby’s meal items contain trans fat, including all of the restaurant’s roast beef sandwiches. Arby’s sides are even more unhealthy, on average. An order of six mozzarella sticks has among the most unhealthy amounts of each of the six nutritional categories, including 2,530 milligrams of salt, just over a full day’s recommended daily allotment.

4. Quiznos
>Pct. meals with 600+ calories: 51.5%
>Pct. meals with 10+ g saturated fat: 61.9%
>Pct. meals with 1,000+ mg sodium: 85.6%
>Pct. meals unhealthy in at least one nutrition category: 86.6 %

One bit of good news for the sandwich shop, Quiznos sides were much closer to the average major fast-food restaurant. However, its main meal options rank worse than any other major fast-food restaurant. Of the just under 100 subs and sandwiches that make up the restaurant’s menu, more than a third had abnormally unhealthy levels of all six nutrition categories considered. Of all the most popular fast-food restaurants surveyed, Quiznos is home to some of the most calorie rich sandwiches — 21 sandwiches have more than 1,000 calories. Seven of those are among the 10 sandwiches with the highest calorie counts, including the Chipotle Steak and Cheddar Sub and its 1,130 calories, one of the most caloric sandwiches among the largest fast-food restaurants.

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3. Whataburger
>Pct. meals with 600+ calories: 36.4%
>Pct. meals with 10+ g saturated fat: 53.0%
>Pct. meals with 1,000+ mg sodium: 69.7%
>Pct. meals unhealthy in at least one nutrition category: 89.4%

Though most of its locations are in Texas, Whataburger is one of the most popular fast-food restaurants in the country with more than $1.5 billion in sales. More than 40% of Whataburger’s sides rank as unhealthy, even compared to other fast-food chains. Nine out of the 10 side items on the restaurant’s menu have above average levels of at least one of the nutrients that are unhealthy if over consumed. Over half of its meal items are in the top third for saturated fat levels. The 1,170 calorie Monterey Melt burger contains 24 grams of saturated fat and three grams of trans fat.

2. Carl’s Jr.
>Pct. meals with 600+ calories: 48.0%
>Pct. meals with 10+ g saturated fat: 58.0%
>Pct. meals with 1,000+ mg sodium: 80.0%
>Pct. meals unhealthy in at least one nutrition category: 84.0%

Carl’s Jr. and Hardee’s, owned by the same company, are by many measures two sides of the same coin. Their logos are almost identical and their menus are similar. Both sell shakes and burgers. However, even with the extremely similar menus, the restaurants are different enough in nutrition that Hardee’s does not even make the list of the 10 least healthy fast-food restaurants, while Carl’s Jr. is the second-least healthy in the country among major chains. Any amount of trans fat is considered unhealthy, and only a small percentage of all the meal items on fast-food menus have more than a milligram of trans fat. Carl’s Jr. sells six different breakfast sandwiches with six grams of trans fat, although none are sold in California.

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1. Sonic
>Pct. meals with 600+ calories: 48.4%
>Pct. meals with 10+ g saturated fat: 49.5%
>Pct. meals with 1,000+ mg sodium: 73.7%
>Pct. meals unhealthy in at least one nutrition category: 87.4%

Sonic, also known as America’s Drive-In, has one of the more unique business models in the fast-food industry — servers on rollerskates deliver the food to parked customers. The restaurant also stands out for having the most unhealthy menu in the country. The average Sonic burger, for example, has 780 calories, roughly 300 calories more than the average burger on a McDonald’s menu. And 10 burgers have more than 1,100 calories. The restaurant is also among the most likely to have above-average levels of trans fat. Nearly half of Sonic meal items have at least 1 gram of trans fat and some items have as much as 3.5 grams. Most menu items among fast-food restaurants have zero trans fat.

Methodology

To determine the least healthy fast-food restaurants, 24/7 Wall St. collected nutrition information on the 50 largest fast-food chains by U.S. systemwide sales for 2013 as reported by QSR, a fast-food publication. Data were collected from Nutritionix, a publicly-available online database of restaurants that includes nutritional information for all menu items.

In an effort to identify comparable fast-food restaurants, we excluded a number of restaurants from our analysis. We did not consider restaurants like Einstein Bros. Bagels or Krispy Kreme, which predominantly serve breakfast items. Chains such as Starbucks, Dunkin’ Donuts, and Jamba Juice were also excluded because their menus are dominated by drinks. Dairy Queen and Baskin-Robbins were excluded for exclusively offering dessert items.

Pizza restaurants were particularly problematic because serving sizes were often listed as a single slice, which nutritional experts agreed did not constitute a meal. For this reason, we were forced to exclude Pizza Hut, Domino’s Pizza, and others from our analysis. Similarly, Mexican restaurants, including Chipotle Mexican Grill and Qdoba Mexican Grill, among others, were excluded because nutritional information was not provided for entire meals. While Panera Bread was listed on QSR’s top-50 rank, it was excluded as a fast-food restaurant from our list.

Lastly, our analysis attempts to identify restaurants that have the potential to serve large segments of the population. For this reason, we did not consider restaurants with fewer than 750 locations in the U.S. For the remaining 20 restaurants, menu items were separated into meals and sides. Desserts, drinks, family-size items, and kid’s menus were not considered.

For the six nutritional measures included in our analysis — calories, saturated fat, trans fat, sodium, carbohydrates, and sugar — we compared each menu item to the equivalent nutrient’s 60th-percentile, calculated from the nutritional measures for all menu items across the 20 restaurants considered. This allowed us to determine the percentage of meals on a restaurant’s menu that exceeded the 60th-percentile cutoff in each nutritional category.

Because being labeled unhealthy in one category was not mutually exclusive with being unhealthy in another category, we used a geometric mean to compute our index. Lower index scores indicated healthier options. We employed the same methodology for sides. Our composite index is the geometric mean of both the meals and sides indices.

One purpose of our analysis was to determine how easily consumers can find healthy options when ordering at these restaurants, if they choose to eat healthy. By using the 60th-percentile, we get a broad indication of the quality of a restaurant’s menu. To be sure, every restaurant has one or two items that are extremely unhealthy for you. However, provided a restaurant’s entire menu was not grossly unhealthy, the restaurant could still perform reasonably well on our index.

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