You probably have had kanji or rice water as a child or when you were really sick. You might not have enjoyed the taste but this humble concoction has various health benefits. Is a good source of energy: Kanji or rice water is rich in carbohydrates and hence an excellent source of energy. The body can easily derive energy by breaking down carbohydrates. Drink a glass of rice water in the morning before heading out and you will never feel dizzy or weak due to lack of energy. Prevents constipation: It is rich in fibre and facilitates smooth bowel movements.