Dear Zone Me In,

The basis for the Zone diet, by Barry Sears, Ph.D. (a biochemist, neither a physician nor a dietitian), is that if a person eats the correct ratio of carbohydrate to protein to fat (40/30/30), s/he will improve his or her health, weight, and athletic performance, because certain hormones will be balanced and therefore in the preferred "zone." The hormones he focuses on are insulin (necessary for glucose to enter our cells) and eicosanoids (hormone-like substances that regulate inflammation. Some eicosanoids are by-products of metabolism.).

Sears alleges that the American public is overweight due to a high intake of carbohydrates, and that this style of eating causes an over-production of insulin. In addition to causing weight gain, excess insulin leads to an imbalance in eicosanoids that he links to other aspects of ill health, such as heart disease, cancer, and arthritis, among others. The solution, Dr. Sears offers, is to eat a lower carb, higher protein, and moderate fat diet to balance these hormones within the preferred "zone."

The positive part about the Zone diet is that it encourages its followers to eat often throughout the day — at least every five hours. It also eliminates foods many people overeat, such as sweets, chips, certain starches, and, of course, junk food. It concentrates on including a number of healthful foods — low glycemic fruits and grains, vegetables, lean proteins, and monounsaturated and omega-3 fats. (Low glycemic foods, such as cherries, grapefruit, nuts, and lentils, don't cause blood glucose levels to increase quickly, and therefore require lower levels of insulin than higher glycemic foods, which include white potatoes, corn flakes, and dates.) The Zone diet works for its followers because it is actually a low calorie diet. For instance, the sample meal plans for an average woman totaled approximately 1200 - 1300 calories per day. Most women would lose weight at this level of caloric intake, regardless of the source(s) of these calories.

Dr. Sears, however, goes to great efforts to offer scientific explanations for the Zone diet that are not proven. His diet does not necessarily lead to more efficient fat burning, nor is there evidence that it lives up to his claims of reduced incidence of disease. Testimonials are not proof, nor are they a substitute for scientific research. The studies he does refer to regarding athletic performance don't meet the standards of high quality, respected research, because no control group was included in their study design. [FYI, a control group consists of a set of subjects alike in every way to the test group, except that they don't follow the experiment — in this case, the diet. Scientists then compare the results of the experimental group (the dieters) to the people who are the "control" (subjects not on the diet), and statistically calculate whether the experiment (the diet) had a significant effect, no effect, or the effect happened by chance. This is the gold standard of scientific research.]

So many diet books are on the market, and many simplify the obesity problem. The truth is, people are overweight for numerous reasons. Although Dr. Sears blames insulin resistance, clear evidence proving this cause for all overweight people does not exist. No two people have the same eating patterns, hormonal profiles, and genetics. The Zone Diet will help people lose weight, not necessarily because of any magic formula, but simply because it is low in calories. In fact, many of the individual meals and snacks do not adhere to his 40/30/30 formula, according to a nutrition analysis of his sample recipes and meals. One area he fails to address in the Zone diet is the aesthetics of eating. All of the pleasure from eating is eliminated when food is regarded as a drug. Dr. Sears also ignores emotional eating, a major reason for weight issues.

It's important to understand that scientific research is evolving in the field of weight regulation. We are learning more about how hormones, other chemicals in the body, and factors influencing appetite affect this area of study. Weight control is much more complex than simply following a prescribed eating plan or a meticulous balance of nutrients. The satisfaction a person derives from his or her food is key in forming a healthful eating plan. For some, slightly higher carbohydrate intake is more satisfying; for others, slightly higher protein works better — the important part is eating a variety of foods, keeping active with regular exercise, and making these changes permanent. Eating plans work as they become part of one's life.

Alice

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