Yes, for both spiritual and dietary reasons. As long as you stay hydrated and are otherwise healthy, fasting for a day or two is perfectly fine (some people go way longer, but it can slow your metabolism down, which can cause weight gain when you cease the fast, and have other effects, so I don't recommend it). I usually break a fast lightly, with a small meal (soup, a little bread, a piece of fruit). It can clear the mind and the digestive system.