Did you know that 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. We've scoured every major fast food chain to highlight the main-meal menu items that contain the least calories. Some of them might surprise you...

Click or scroll through our gallery to discover the lowest-calorie picks from your favorite fast food brands – counting down to the least calorific main-meal menu item of all.

We've based our ranking on the latest nutritional data provided by each fast food chain.