My husband did a juice only fast for 11 days for weight loss. He lost 14 lbs., stopped snoring almost completely AND had much less severe sleep apnea, had more energy and felt very focused BUT his eyesight got blurry. His eye dr. told him he should have never gone on a juice fast only because of his diabetes. I did the juice fast for 3 days (I noticed I had more energy and my breath didn't smell as bad in the morning like when I eat meat) and then switched to juicing/smoothie for 2 meals and 1 regular small meal a day-I did that for 4 days and for the 7 days lost 4 lbs. Now I make a smoothie for breakfast. I put whatever fruit I have on hand, a kale leaf, a few baby carrots, yogurt, coconut water, and powdered protein in it. It's yummy and usually fills me up for several hours. My best advice to you is to talk to your dr. BEFORE you start juicing-especially if you are going to do a fast or substitute meals with the juice.