zone diet

Zone diet is developed by Dr. Barry Sears, a former research scientist at the Boston University School of Medicine and the Massachusetts Institute of Technology. Due to the premature death of his father at age 53, Dr. Sears began his dietary studies to find a way to prevent heart disease and to maintain health. Therefore he began to do researches on the role of fats in the development of cardiovascular disease. His landmark book, The Zone, was published in June 1995. The book has been sold more than 2 million hardcover copies in United States, and has been translated into 22 languages (Foreman 2009). This indicates a good worldwide response to his research. The author has written a few more books following his first publication, and all are bestsellers in United States (Foreman 2009). In addition, Sears had published another book named The Soy Zone where he has outlined a Zone diet based around soy protein and soy foods for vegetarians who wish to adopt Zone diet.
Basically, Zone diet is a low-carbohydrate, high-protein eating plan with macronutrient and glycemic load modification. Average daily caloric allowance of Zone diet for women is about 1,100 calories and 1,400 calories for men. It suggests that 40% of total calories per day should come from carbohydrate, 30% from protein and remaining 30% from fat. Thus, Zone diet is also known as the 40:30:30 diet plan. Dr. Sears claimed that this is the optimal mix in which the human body is genetically programmed and will allow the body to enter an efficient metabolic state (Cheuvront 2003). It is not necessary to count the calorie for Zone diet. Instead, the right serving size of each macronutrient (carbohydrate, protein and fat) is estimated merely by using the “eyeball” method (Sears 1995).
In Zone diet, it emphasizes the protein-to-carbohydrate ratio (P:C) of the diet to be 0.75. This is about three times the ratio resulting from conventional diet recommendations, which is only 0.25. It claims that a 0.75 P:C diet can reduce the insulin to glucagon ratio (I:G) which allow excess body fat to be burned and ultimately lead to the production of “good” eicosanoids (Sears 1995). In other words, Zone diet postulates that diet, hormones, and eicosanoids are interrelated and may leads to improved health. Dr. Sears believes that significant swings in insulin levels affect mental status, mood, endurance, and weight gain or loss (Sears 1995). Uncontrolled insulin levels over time will have an adverse effect on the overall health and well-being.