Lettuce is an amazing weight loss food that is extremely low in calories and rich in vitamins A, C and K along with iron, thiamin, folate, potassium, manganese, riboflavin, calcium, Vitamin B6, copper, and magnesium. Choose Romaine lettuce over Iceberg because it has more health benefitting nutrients. It is grate for skin as well because it supplies the necessary nutrients to the skin and increases oxygen flow. It helps in flushing out toxins from the system while the carotenoids help in fighting cancer. The best way to juice lettuce is by rinsing the leaves and putting them into the juicer.