The Zone diet, otherwise referred to as the “40-30-30” diet, is an eating plan that consists of 40% complex carbohydrates, 30% unsaturated fat and 30% protein. Barry Sears, PhD, a former MIT biotechnology researcher, and author of the diet book, “Enter the Zone,” reports that people who choose to follow this diet emerge “feeling alert, refreshed, and full of energy.” Sears and the co-author of the book, Bill Lawren, contend that living life in “The Zone,” is at the heart of wellness. Due to his background in research, the book’s author delves considerably into discussions of what he touts the science-based theory behind the diet.
The diet’s developers claim that by changing the body’s metabolism with the 40-30-30 formula, Zone dieters can expect to halt encroaching high blood pressure, heart disease and diabetes. They also attribute the diet to an increase in the quality of athletic performances. The claims are largely anecdotal, however. The research needed to make them more credible is not included in the book.
The premise of The Zone Diet, is that contemporary thinking based on a diet that is low in protein and fats, yet high in carbohydrates, is headed down the wrong path. Sears believes that the typical American diet contributes largely to higher risks of contracting life-threatening diseases such as diabetes and potentially, cancer. He has written a second book that more closely examines the concept of disease and how The Zone Diet fights the inflammation that he claims is an underlying contributor to the development of diseases and obesity.
A unique feature of The Zone Diet is the recommendation that participants not lower their caloric intake, but that they switch to different kinds of calories. It recommends that dieters consume small amounts of protein at each meal, and with the two snacks that are recommended in late afternoon and late evening. It further recommends what the book terms as, “favorable” carbohydrates that amount to double the size of the portions of protein. Among the carbohydrate choices are most vegetables, beans, fruits and whole grains. If dieters choose carbohydrates that the book’s authors identify as, “unfavorable” ones, it is recommended that they eat less. These foods include carrots, bagels, tortillas, brown rice, pasta and other foods. The diet discourages the consumption of dairy products, based on their fast production of glucose into the blood stream. However, they are not entirely forbidden. The diet minimizes the use of saturated fats, but does allow small amounts of avocado, certain types of nuts, canola and olive oils.
Nutrition experts have given the diet mixed reviews but it does seem to be a diet that works. A rating team of researchers who work for the Center for Science in the Public Interest, did place the diet on their list of “acceptable” diets. However, the nutrition director, “Nutrition Action Healthletter,” the organization’s publication, cautioned users to ignore the scientific rhetoric, claiming that the diet, “isn’t bad.” While people can lose weight and maintain their health on The Zone Diet, the organization contends that it restricts carbohydrates more than is necessary and it is probably not be the best way to lose weight.