Does anyone know if the Islamic fast is the strictest? What about Judaism, Christianity, Hinduism, Buddhism, Sikhism? And the other -isms? BTW Being forty days tempted of the devil. And in those days he did eat nothing: and when they were ended, he afterward hungered. Luke 4:2 Jesus fasted without food (and water?) so where do Christians get the idea of giving something up for the 40 days of Lent? It was a strict "proper" fast!