Lettuce is a common fresh vegetable that can be consumed normally by most people. However, individuals with allergies should abstain from eating lettuce if they have a food allergic reaction to it. Lettuce is a kind of vegetable that contains more water, fresh lettuce is about 95% water, so it has a crisp texture and is one of the vegetables that many people like to eat. Lettuce also contains some of the nutrients needed by the human body, such as 100 grams of lettuce containing about 1.0 grams of protein, about 2.8 grams of carbohydrates, about 150 milligrams of carotenoids, about 4 milligrams of vitamin C and so on. Most people can safely consume romaine lettuce to supplement their bodies with the above mentioned nutrients. However, individuals with allergies should abstain from eating lettuce if they have a food allergic reaction to it. In addition, lettuce can only be used as a vegetable food, belonging to the side dishes, the daily diet to do a reasonable arrangement of the main and side dishes, to ensure balanced nutritional intake.