It's just a friken, unsubstantiated and abnormal fad. Just like Polyphasic sleep, the master cleanse all liquid diet, and James Bond life-style advocated in the 4 Hour Work Week.

These are extremist ways to alter one's lifestyle, and it's usually done by people who want MORE than they already have, not people who are forced by circumstances to eat raw foods, or sleep 2 hours a day, or work 4 hours a week or only consume liquid diets.

And from my experience, people susceptible to these fads make for awful companions and hangout buddies. Sure, Voltaire might have advocated for the Noble Savage who lived in harmony with nature, but the SOB was writing praises to nature and animal-like living when he was himself collecting royalties, living in castles and rubbing shoulders with European nobility.