Which lettuce is best? A definitive ranking of the healthiest greens you can buy.

Eating salad is a favorite pastime of many health nuts, but not all salads are created equal. Those loaded down with creamy dressings and cheese and bacon bits are often shamed for their Big Mac-like calorie counts, but beyond the toppings, even the mainstay of a good salad — lettuce — has its ups and downs. 

So, which lettuce is best? 

While no lettuce is particularly bad for you (unless it's covered in pesticides, but that's another story), your salad bar choices can have a serious impact on the overall healthifulness of your salad.

A good general rule is to go for the darkest greens, as darker leaves pack in more nutrition. "Stay away from Iieberg lettuce, it's 96% water and not much else, registered dietitian Kimberly Gomer said in an email. "Go to dark, leafy greens... The darker the green, the more antioxidants (those good heart protecting nutrients) are present." So why do darker greens pack more nutrition? Gomer adds, "When the leaf is darker, it has a greater ability to absorb more light which in turn allows it to synthesize more vitamins." 

And you don't have to completely hail kale!  Homer suggests mixing up your greens rather than using the same base for every salad to get a variety of nutrients and, of course, flavors. 

Stuck at all the salad bar options? Here are the best choices when you're really tempted to just go for the Caesar. 

Kale 

High in vitamins A, C and K as well as iron, calcium, and potassium, "this leaf has the cancer fighting phytonutrients (plant chemicals) that are so good for us!" Gomer said. 

Spinach

Another nutritionist-approved favorite, spinach is high in vitamins A,C, K, iron, calcium and potassium as well as folic acid, which Gomer noted is "very important for childbearing years and processing energy." 

Swiss Chard 

With nutritional qualities similar to spinach, including vitamins A,C, K, iron and folic acid, swiss chard adds another level of crunch and color, if you go for the rainbow variety. If raw chard is too bitter for your taste, try sautéing it with tomatoes and white beans for a quick cooked salad that can be enjoyed warm or cold.  

Cruciferous Greens 

Cruciferous greens may not be on the menu at your local salad spot but this category includes arugula, collard, kale, mustard, turnip greens and more. "These greens, along with their phytonutrients, have the added benefits of cancer preventing isothiocyanates and indoles, making them an awesome choice," Gomer said. 

Salad just got so much more exciting, no?