Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Zone diet is a diet popularized in books by biochemist Barry Sears. It advocates consuming calories from carbohydrates, protein, and fat in a balanced ratio.The diet centers on a "40:30:30" ratio of calories obtained daily from carbohydrates, proteins, and fats, respectively. The ideal formula has been under debate, although studies over the past several years (including a non-scientific study by the PBS documentary show Scientific American Frontiers) have shown that it can produce weight loss at reasonable rates.The Scientific American Frontiers study compared the effectiveness of several popular ''diet'' regimes including the Zone; somewhat to the surprise of the show''s staff, the participants on the Zone experienced the greatest fat loss while simultaneously gaining muscle mass.Participants also reported the Zone as the easiest regime to adjust to, i.e. having the fewest adverse affects such as fatigue or hunger.Most people who report fatigue find that the fatigue diminishes by day 2 or 3.