What is it?
The Zone is the brainchild of Barry Sears, PhD, a biotechnology research scientist from MIT. Sears's philosophy, which has been extensively featured in his series of popular books, is that food can affect the hormonal response of the body and cause changes in insulin production. According to Sears, a food plan with a balanced ratio of carbohydrates (40%), protein (30%), and fat (30%) is the optimal mix for how the human body is genetically programmed and will allow the body to enter an efficient metabolic state (a.k.a "The Zone"). Therefore, more emphasis is placed on maintaining this ratio, rather than on cutting calories (although the diet does recommend a daily consumption of 1200 calories for women and 1600 for men).
The Zone requires that a small amount of lean protein be eaten five times a day—at the three meals and two snacks that are part of the eating schedule—and also promotes "favorable" carbohydrates, such as most fruits and vegetables, beans, and whole grains. The diet also includes unsaturated "good" fats from olive oil, nuts, and avocados. Moderate exercise for 30 minutes a day, six days a week is another component of The Zone lifestyle. From his original 1995 book, Enter The Zone, Sears has built a diverse brand, complete with a variety of food products, dietary supplements, and a skin-care line.
Like other popular diets, The Zone promises more than just weight loss, preferring to be called a "lifestyle" and shunning the word "diet." By revamping the body's metabolism with the 40-30-30 ratio, The Zone claims to minimize the risk of diabetes, heart disease, and high blood pressure and slow the aging process by adopting an "anti-inflammatory lifestyle." The Zone promise a lifetime of wellness that only begins with changes in your diet. Through regular consumption of omega-3 fatty acids, the diet promises to reduce "silent inflammation" and enhance the function of the immune system.
Sears claims that the science behind The Zone is based on his 15 years of research in bio-nutrition, and there is plenty of anecdotal evidence of success. In fact, The Zone information website has an entire section dedicated to celebrity testimonials — with an odd mix of actors, bodybuilders, musicians, journalists, supermodels, and professional athletes (including a curious number of NFL football players who are or have been affiliated with the New York Jets).
Pros & Cons
Nutritionists have given The Zone diet mixed reviews, as is generally the case with many branded diets. It's hard to argue against a menu that calls for lean protein, good fats, fruits, vegetables, and whole grains. And the diet restricts simple carbohydrates that have low nutrition value. Also, despite the confusing and complex jargon in Enter The Zone (in fairness, Sears claims the first book was targeted at cardiologists), the diet itself is not overly complicated to follow. The routine is the same for every meal — measure out your protein (usually just enough to fit in the palm of your hand), fill the rest of the plate up with fruits and vegetables, and work in some omega-3 fatty acids — and the acceptable foods list is fairly broad.
Questions arise, however, in the 40-30-30 ratio of protein-carbs-fats. The American Heart Association (AHA) is one of the more high-profile critics of The Zone, stating that the high protein consumption is not a healthy way to lose weight and that there is no scientific evidence that this diet is effective for long-term weight loss (a similar argument against many branded diets). Some nutritionists have criticized the conclusions that Sears gleaned from the scientific evidence, stating that he twisted and stretched his basic research into his philosophy for The Zone.
We at Healthline are all about a practical approach to a healthy lifestyle, and our philosophy on dieting is no different. There are some groups in the health industry that denounce all popular dieting trends without question or consideration, and that is fine. There are some trends that need to be denounced. But with others, if you simply take a practical and safe approach and consult your doctor in the process, there is a good possibility that you will lose weight effectively and in a healthy manner.
Compared to other diets in the pop culture/fad category, there is nothing too extreme about The Zone (except for its brand marketing and weird science claims). It calls for a relatively balanced diet of healthy foods to go along with a regular exercise routine. That we like. The specific ratios and overblown claims of genetic and hormonal manipulation we can do without. But if those sorts of things motivate you to eat healthier and go for a regular 30-minute jog, then so be it. A diet doesn't necessarily need scientific proof to be deemed effective at causing people to lose weight. If people follow the plan and shed pounds, then the diet does what diets are supposed to do.
However, an unbiased, reputable scientific study that reveals long-term health risks (or the lack thereof) would be nice. Unfortunately (and curiously), this kind of research is rare for most branded diets. Few major health organizations ever endorse fad diets, so the AHA's criticism is not uncommon. But it's definitely worthy of consideration, especially if eating high amounts of protein puts your health at risk because of other conditions. The best thing for you to do when considering any diet or lifestyle change is to consult your health care provider to help figure out what is best for you, to assess any health risk involved, and to see if there are any better options out there.