Newsweek spoke with Nelly J. Aguilar, a writer and creator who recently undertook a 30-day water-only fast. "I'm no stranger to fasting," Aguilar explained. "I've experimented with several shorter ...

But some advocates of the practice take this to the extreme, consuming nothing but water for weeks on end. Proponents, who fast for 30 or more days at a time, say the practice helps the body heal ...