The Zone Diet Health Article

Definition

The Zone Diet program is a food management system that claims to promote optimal metabolic efficiency in the body by balancing the hormones insulin and glucagon. Insulin is responsible for converting, in the blood, incoming nutrients into cells. Glucagon regulates glucose in the liver. The Zone's food plan consists of a dietary intake of 40% carbohydrates, 30% protein, and 30% fat.

Origins

In 1995, Dr. Barry Sears, Ph.D., a former biotechnology researcher for the Massachusetts Institute of Technology, authored The Zone. Since that time, the book has sold over one million copies. One of the more popular carbohydrate-restrictive diets, the Zone's success has recently spawned several Zone "knock-off" diets. The Zone Diet is based on a program Dr. Sears developed almost twenty years earlier to treat heart disease in Type 2 diabetics. One of his key inspirations for developing this program was his own genetic history, which demonstrated an inclination for premature heart attack.

In a web interview for WebMD Health, Spending a Week in the Zone with Barry Sears, Ph.D., Dr. Sears explained that he believed that the primary cause of heart disease was not high cholesterol but high levels of insulin; and that the Zone Diet is designed to control insulin levels and thus promote better health. Dr. Sears continues to promote his diet through speeches and his web site, http://www.drsears.com/.

Benefits

The name of Dr. Sears' diet refers to an expression used by athletes to describe a euphoric state of optimal physical and mental efficiency. At its heart, the Zone Diet strives to control two metabolic hormones, insulin and glucagons, as well as properly balance eicosanoid metabolism. Eicosanoids, found in fatty acids, are important in the regulation of inflammatory, immunological and hemostatic (arresting hemorrhage) processes. Metabolism is the chemical process in living cells that provides the body with energy and new material to repair waste. In addition to permanent weight loss, this hormonal balance is said to increase longevity and blood flow, improve the immune system, and promote a sense of general well being. Furthermore, the Zone Diet is thought to assist in the prevention of chronic ailments such as diabetes, heart disease, and high blood pressure.

Description

The diet asserts that by controlling the glucagons-insulin ratio in the body, it promotes long-term weight loss as the body burns excess fat. In addition, it is claimed that balancing levels of eicosanoids further increases mental and physical performance and reduces inflammation and hunger. This state of hormonal balance, also referred to as "the Zone," is achieved, according to the diet, by maintaining a dietary ratio of 40% carbohydrates, 30% fat, and 30% protein. It is this dietary ratio that has led people to call the Zone a "40/30/30 diet."

The Zone diet requires eating five times a day—three full meals as well as a mid-afternoon and pre-bed-time snack. The dieter is told that he/she should eat at least once every five hours to maintain proper insulin levels. There are two distinct methods used when preparing a Zone meal: the Eyeball Method and the Block Method. Following either method should provide a daily caloric intake of roughly 1,200 calories for women and 1,500 calories for men.

With the Eyeball Method, the dieter's hand is used to judge portion sizes. For low fat proteins (chicken and fish), the portion should be approximately the size and thickness of the dieter's palm. This equals roughly three ounces of protein for women and four ounces for men. Then carbohydrates are added to the meal. For "favorable" carbohydrates, such as most fruits and vegetables, two loose, fist-sized portions may be added. For "unfavorable" carbohydrates, such as pasta and grains, only one tight, fist-sized portion may be added. Finally, a "dash" of dietary fat is added, which can consist of a few nuts, olives, or guacamole.

The second, and more precise, method for the Zone diet is the Block Method. In this method, each "Zone Food Block" consists of three "mini-blocks," which each represent one portion each of low-fat protein, favorable carbohydrates, and dietary fat. These mini-blocks contain a precise measurement of these macronutrients, specifically seven grams of protein, nine grams of carbohydrates, and 1.5 grams of fat. Each of the three daily meals and snacks consists of a set number of blocks. Women should consume three blocks per meal and one block for each snack, totaling eleven blocks each day. Men should consume four blocks per meal and one block for each snack, totaling 14 blocks each day. These are considered the minimum daily nutritional requirements for an adult. Different factors, such as increased muscle mass and pregnancy, may increase the daily food block requirements.

The Zone diet is only one of four key elements in the entire nutritional program proposed by Dr. Sears. The other three elements are the use of monounsaturated fats, dietary supplementation of Omega-3 fish oils, and exercise. These other elements, it is asserted, will help control metabolic function, produce "good" eicosanoids, and lower insulin levels. These four elements combined should produce a positive hormonal balance and thus increased health and permanent weight loss.