I am not one of the experts but I can tell you about my recent juice-fast. It worked! I stopped all solid food and drank only freshly made fruit and vegetable juice, water, teas (and a bit of coffee). I was rarely hungry and lost almost a pound a day. I did it for 18 days. My understanding is that raw fruit and veggies only yield like 30-35% of their nutrients if you just eat them, but when you juice them you get 90% and it is absorbed right into your system. You don't want to ingest the pulp of any matter that must be digested because then your body will not go into fast mode. When you actually fast and take nothing but almost clear liquids, you digestive system sort of goes to sleep for a while. That's how it feels. Hunger leaves you alone and your system gets a rest. It feels wonderful. The hardest part is getting started. After half a day you will get a high off the experience and want to continue. You should also cleanse your colon a bit in whatever way you prefer while fasting.