I did a 12 day water and a 12 day juice fast before. The thoughts for food don't diminish. The hunger goes away after the 3rd day.
I've been reading more and learning that as a society, we have trained ourselves to eat out of habit and cravings rather than hunger. I'm on day 5 and don't feel truly hungry even though my stomach grumbles. We're just so used to life being centered around food that it makes it hard to fast. I believe that each day completed on a fast gives us that much more strength to say no to bad eating habits and yes to a healthier life style.