Did you know a White Castle Original Slider has fewer calories than a chocolate milkshake? We all crave fast food every now and again, but some menu options are less calorific, and in some cases healthier, than others. Here we look at every major fast food chain and highlight the main-meal menu items that contain the least calories. Some of them might surprise you...

Did you know that if you swap Original Recipe Chicken for Kentucky Grilled Chicken, you'll consume around half the calories? This healthier option comes in at just 80 calories for a drumstick and 70 calories for a wing. In terms of sides, opt for a serving of green beans to complete your meal.

There are plenty of healthy options at Panera Bread, from oatmeal bowls and smoothies to soups and salads. If you’re heading there for lunch, a bowl of Ten Vegetable Soup comes in at only 100 calories. If you order the bread bowl version of this soup, however, that jumps up to 730 calories.

It's known for its fried chicken sandwiches and waffle fries, but if you're looking for lighter options at Chick-fil-A, you're in luck. Eight grilled nuggets clock in at 130 calories compared to 250 when breaded and cooked in oil. For something more substantial, we like the Grilled Chicken Sandwich with a multigrain brioche bun, lettuce, tomato, and lemon-herb marinated chicken breast (380 calories).

One of the country's first fast food chains, White Castle has been credited for inventing the slider. However, what people might not know is that the iconic item is probably also the lowest-fat option on its menu. With fewer calories than a chocolate milkshake or French fries, the Original Slider – a beef patty steam grilled on a bed of onions, served with a pickle in a bun – contains just 140 calories. It might not fill you up, but it's a good option if you're looking for a snack-size treat without going overboard.

This food-court favorite might be known for its Orange Chicken (490 calories, just so you know) but it's the Broccoli Beef that wins when it comes to healthier options, at only 150 calories. Pair it with a 90-calorie side of super greens, or turn it into a fiber-rich main meal with steamed brown rice.

Lower calorie options on the menu at Subway include the Veggie Delite six-inch sub (200 calories). But for the best nutritional buck per bite, try the Oven Roasted Turkey Protein Bowl, loaded with veggies and topped with the amount of turkey on a footlong, but without the bread. With no dressing or cheese, it’s 150 calories and provides 60% of your Daily Value of vitamin A, plus a whopping 25g protein.

If you’re looking to cut back at Arby’s, check out its Sliders. You could grab a Roast Beef Slider for just 167 calories or, if you like it spicy, you could add jalapeños to your bun for an additional 10 calories.

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Ignore the donuts at Dunkin’ and turn your tastebuds to the all-day breakfast menu instead. It has a wide variety of diet-friendly sandwiches, including a Veggie Egg White Wake-Up Wrap for 190 calories. Looking for something indulgent for lunch that won’t break the calorie bank? The Kosher Grilled Cheese contains 420 calories and packs a punch of bone-building calcium.

Everyone loves a buttery almond croissant from Starbucks but, along with 420 calories, each of those flaky morsels has 11g saturated fat – half the recommended daily intake. Swap it for a two pack of Bantam Bagels stuffed with vegetable cream cheese for only 200 calories. Those looking for an energy boost can opt for a reduced-fat Turkey Bacon, Cheddar & Egg White Sandwich, which has 230 calories and 17g of protein.

This global pizza chain is hard pressed for healthy options – and that’s partly why we love it. But, if you do want a lighter choice, pick the three pieces of Boneless Chicken (170 calories) or the Chicken Caesar Salad (220 calories, but go easy on the dressing). Otherwise, customize a small 10-inch thin pizza with marinara, ham, green peppers, mushrooms, and onions (skip the cheese), for 560 calories. 

Sonic Drive-In's Corn Dog clocks in as its lowest-calorie light meal at 230 calories. Looking for something in a bun? Try a Chicken Slinger (350 calories): a brioche roll stuffed with juicy chicken, crinkle-cut pickles, and creamy mayo.

In-N-Out Burger is all about burgers, fries, and shakes. The healthiest is the regular Hamburger with onions, mustard, and ketchup (no spread), for 310 calories and 16g of protein. However, order it Protein Style and the bun can be replaced with lettuce, making your meal an even more slimline 240 calories. A cheese slice adds 90 calories and 4g saturated fat but also supplies calcium and a further 5g of filling protein, so it’s not a bad addition.

Portion control is the key to keeping calories low at Wendy’s, and the Jr. Hamburger is your best option at 250 calories. Regular-sized burgers such as the Dave’s Single (590 calories) are more than double that, increasing to a belly-busting 1,220 calories for the Big Bacon Classic Triple. There are some healthier options, though – at 460 calories without dressing, an Apple Pecan Chicken Salad offers the best trade-off when it comes to calories versus nutritional value.

This mainly West Coast and southwestern US chain may be known for its tacos and all-day breakfasts, but its healthy dining menu makes weight-watching a breeze. It includes a Grilled Chicken Salad for 250 calories (add 25-calorie balsamic vinaigrette to keep it slimline), Grilled Chicken Strips with Teriyaki Dipping Sauce (310 calories), and a wholegrain Chicken Fajita Pita with salsa (330 calories).

There are 480 calories in a large portion of McDonald’s World Famous Fries, but ditch the sides and you can get away with surprisingly few calories. For example, for around 300 calories you could have a Sausage Burrito or a classic Cheeseburger. What’s more, the original Hamburger trumps the lot at just 250 calories.

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If you’re looking for leaner fast food at Burger King, go for the Hamburger. The beef patty topped with pickles, mustard, and ketchup on a sesame seed bun provides 13.8g of protein and only 259 calories. That’s a little more than a third of the calories contained in an iconic Whopper. The hamburger is lower than you’d think in saturated fat too, with 4g per serving – that's around 18% of the 22g recommended daily maximum.

This all-American chain is known for its root beer, burgers, and specials like Sriracha Cheese Curds. But what do you order if you’re trying to be healthy? A plain hot dog is 310 calories, but three hand-breaded chicken tenders are the lowest calorie option at 260 calories – and with 40g of protein, they should be filling too. To keep it light and healthy, choose BBQ sauce as your dip (40 calories), and team with a 3oz serving of coleslaw (100 calories).

If calories are your main concern, take a look at the 280-calorie Charbroiled Chicken Salad at Carl's Jr., made with charbroiled chicken breast, red onion, tomato, a four-cheese blend, and croutons on a bed of iceberg lettuce. But if you don’t want to do without a burger bun, the Charbroiled BBQ Chicken Sandwich is a leaner 370 calories.

Not short of decadent desserts and drinks, Dairy Queen isn’t bad for dieters either. Alongside pies and milkshakes it offers some pretty good healthy options. Found on some local menus, a corn dog is only 240 calories – but the Rotisserie-style Chicken Bites Salad Bowl is available everywhere, and contains 320 calories. It provides 37g of protein and a couple of veggie servings.

Heading to the home of the ShackBurger? There’s only one thing to order if you’re counting calories – a 100% beef Hot Dog, which comes in at 350 calories. A portion of Double Down fries is a whopping 1,910 calories – definitely one to avoid if you're watching your waistline.

An average Whataburger meal including fries and a drink clocks in around 1,800 calories, but you can choose a healthier option by ordering from the Lighter & Smaller menu, where everything is under 550 calories. A Bacon Taquito will set you back only 355 calories, while providing 18g of protein. It’s a better choice than the sausage version as it has 2g less saturated fat (7g versus 9g).

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Buttermilk biscuits, buckets of crispy fried chicken, and comforting sides might be Popeyes’ thing, but take a closer look at the menu and there are a few healthier choices. You could order eight chicken nuggets for 380 calories, then add fibre and vitamin C by also getting the green beans – just 60 calories for a regular portion. The lowest-calorie sauces? Bayou Buffalo (60 calories) and Creole Cocktail (40 calories).

For maximum vegetables and minimum waistline impact go for Denny's Fit Fare Veggie Skillet, which comes with red-skinned potatoes, bell peppers, onions, mushrooms, broccoli, spinach, tomato, scrambled egg whites, and salsa. It’s high in protein and fibre, is gluten-free, and has just 390 calories.

Known for its ButterBurgers and fresh frozen custard shakes, Culver’s is one of the Midwest’s favorite chains. But those looking for healthier options needn’t miss out. The Grilled Chicken Sandwich is only 390 calories. It also supplies 14% of your daily recommendation of anaemia-protective iron, and only 2g of cholesterol-raising saturated fat. The ButterBurger Single is also 390 calories, but higher in saturated fat, at 7g.

It’s not easy to cut the calories at Five Guys as even its Little Burgers contain a minimum of 540 (before bacon or cheese are added) – and don’t even get us started on the 'little' fries (530 calories). For a comforting choice that also has a pile of bone-building calcium, we’d opt for the grilled cheese (470 calories). Toppings are free and there are some healthy, low-calorie options you could add, including grilled mushrooms (20 calories), grilled onions (10 calories), and tomato (10 calories).

As much as you might crave a comforting burrito, the healthiest option at Chipotle is a build-your-own salad bowl. To clock in at 520 calories, choose a combination of steak or sofritas (a meat substitute), black beans or pinto beans, fajita vegetables, and tomatillo green-chili salsa.

Ignoring appetizers and sides (because if you wanted chicken wings, you’d probably go to KFC), the healthiest option at Pizza Hut is a six-inch Personal Pan Pizza. The Veggie Lover's Personal Pan, a tomato, mushroom, red onion, green pepper, and black olive pie, comes in at 560 calories. It’s also the lowest sodium option, but still has 50% of your daily recommendation (too much sodium can raise blood pressure). Hawaiian Chicken is another relatively healthy option at 600 calories.

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