I got downvoted heavily last time I mentioned this on HN, but I have done 90 days on fresh vegetable juice several times in my life, and it feels amazing. I've gotten several 60+ year old people to try it, including my father, and all achieve great weight loss (30-45 lbs). One 63 year old male even had blood work done before and after, and even though he lived on only vegetable and fruit juice for 90 days, basically ALL his metrics improved. Even glucose and A1C improved, which shocked his doctor since he was living on basically only sugar for 90 days.