It's appealing to think that fasting might be an ancient survival mechanism that triggers healing processes in the body, as many fasting researchers suggest.
But that doesn't mean all forms of fasting are the same or that they have the same health effects — many will vary from person to person, and you should always consult your doctor before trying any severe dietary changes.
In his new book, "The Longevity Diet," Longo cautions against using the term "intermittent fasting" too broadly. We know various forms of fasts — only eating during certain hours, restricting eating one or two days a week — are associated with health benefits. But we don't know that all these health benefits are the same for all fasts.
But even so, many of these intermittent fasting regimens are considered relatively safe for a healthy person. So if they appeal, they could be worth a shot. And they may come with a host of health benefits.