Lentils contain high levels of proteins, including the essential amino acids isoleucine and lysine, and are an essential source of inexpensive protein in many parts of the world for those who adhere to a vegetarian diet.Sprouted lentils contain sufficient levels of all essential amino acids, including methionine and cysteine.Apart from a high level of proteins, lentils also contain dietary fiber, folate, vitamin B1, and minerals. Red entils contain a lower concentration of fiber than green lentils (11% rather than 31%). Health magazine has selected lentils as one of the five healthiest foods.Lentils are a good vegetable source of iron. This makes them useful for preventing iron deficiency.