The only person I know that subscribes to the idea of total fasting is my dad. So, I would agree that it is really a marginal action, but not an action that never happens. Even though muslims do break their fast, I think this idea of total fasting stems from religion in most cases. I don't see how anyone could realistically believe that it is a good and worthwile means to lose weight. The negative side affects are just to substantial. I can say that it definitely did work for my dad, but of course going 30 days without food would cause weight loss. I would dissagree wholeheartedly if he told me it was a healthy way to lose weight, though.
RE: Fasting and Its Metabolic Effects - Counterintuitive Perspective [Dr. Steven Phinney]