Generally, leafy greens like kale, spinach and romaine lettuce are considered critical components of a nutritious diet. Yet one leafy green, iceberg lettuce, often gets the cold shoulder.

Here's which types of lettuce are most popular, why these greens are good for you and what you need to be mindful of as you include more in your diet.

Iceberg has a good shelf-life and can be kept for up to seven days in the salad drawer of the refrigerator.