One cup of lettuce has 0.6 grams of carbohydrates. It also contains 0.5 grams of fiber. With an estimated glycemic load of zero and caloric value of seven, it is considered a "free" food in many diets. This includes diet plans for diabetics.
Along with its low carbohydrate content, lettuce has other nutritional values. It contains vitamins A and C, folate, and potassium. It is also a good source of vitamin K and thiamine.
Although all lettuce varieties are healthy, darker-leafed varieties contain higher levels of certain vitamins. For example, romaine lettuce offers 17 times the amount of vitamin A than iceberg lettuce.