Dr. Barry Sears is the highly acclaimed author and creator of The Zone Diet. If you were at all tuned in to the world of health and nutrition in the mid-to-late 90’s you’ve almost certainly heard about and/or experimented with his unique dietary recommendations that calls for a specific ratio of carbohydrates, fat and protein. Since then, Dr. Sears has gone on to research and report on novel ways to address disease and obesity by countering “silent inflammation”. His bestselling books, The Anti-Aging Zone, The Omega Rx Zone and Toxic Fat, all reflect the latest medical findings and practical ways for the average person to modify health risks via natural means. Recently, Dr. Sears took some time out of his busy schedule to answer some of my questions. This is part one of my two-part interview with Dr. Barry Sears.

JP – How did you come to the conclusion that a diet consisting of 40% carbohydrates, 30% fat and 30% protein represents an ideal ratio of macronutrients for most people?

Dr. Barry Sears – The ratio of 40/30/30 is not some magical ratio but rather a range (± 10% for any one nutrient) that was designed to control hormonal responses that lead to chronic cellular inflammation. The balance of carbohydrate to protein comes from a New England Journal of Medicine article in 1985 that gave a proposed balance that might be found in neo-Paleolithic diet before the invention of agriculture. The fat composition is based on what appeared to be a level that could be sustained for a lifetime. Since the publication of The Zone in 1995, clinical trials testing that ratio under controlled conditions have indicated that it is the best marcronutrient balance for burning fat faster, suppressing hunger, and reducing cellular inflammation. In fact, the 2005 dietary guidelines from the Joslin Diabetes Research Center at Harvard Medical for treating obesity and diabetes were essentially the same macronutrient balance. (1,2,3)

JP – Within the context of a 40-30-30 diet, how important is food selection and nutrient density? Will any foods that reach the desired percentages do?

Dr. Barry Sears – The balance of macronutrients is only the beginning. The carbohydrates should have a low glycemic load. This means eating primarily vegetables and fruits, with very limited amounts of grains and starches. The fats should be low in omega-6 and saturated fats as they cause cellular inflammation. The protein should be low-fat protein.

JP – Over the past 15 years or so, have you modified the original “Zone Diet” in any significant way? If so, can you please explain how and why you’ve done so?

Dr. Barry Sears – Actually there is nothing proposed 15 years ago that is any different today. The only differences are advances in molecular biology that have confirmed my basic hypothesis of the power of the Zone Diet on genetic expression by controlling cellular inflammation.

JP – In 2003 you published a paper entitled, “A Proposal for a New National Diet: A Low-Glycemic Load Diet with a Unique Macronutrient Composition”. In that piece, you review dietary changes that have occurred in recent years that appear to be contributing to many of the most common diseases we see today. Have you seen any progress in terms of incorporating some of your findings into the USDA’s Food Guide Pyramid? (4)

Dr. Barry Sears – Unfortunately not. The current USDA recommendations are so confusing as to be worthless.

JP – In some ways, The Zone Diet attempts to turn back the clock to an earlier style of eating by lowering the consumption of refined carbohydrates . On the other hand, you recommend eating more frequently (3 meals and 2 snacks/day) than in previous generations. Why do you endorse this specific eating pattern?

Dr. Barry Sears – The Zone concept is based on my background in drug delivery technology in which you try to maintain a constant level of the drug in the bloodstream. The Zone Diet seeks to maintain a constant hormonal balance in the bloodstream that needs to be re-established every five hours, hence the five meals per day. This is because the hormonal levels will only last 4-6 hours between a meal or snack.

JP – To what extent do you ascribe to the “calories in, calories out” notion of weight loss? Have you found any sort of metabolic advantage in those implementing a 40-30-30 diet?

Dr. Barry Sears – Weight loss and weight gain are far more complex than simply “calories in, calories out” thinking. My newest book, Toxic Fat, describes the intricate hormonal signaling in the brain that can be disrupted by cellular inflammation as well as the activation of a “fat trap” also caused by cellular inflammation in genetically predisposed individuals. Unless cellular inflammation is reduced, long term weight control will be impossible. (5)

JP – How important a role do non-dietary lifestyle factors such as exercise, spirituality and stress reduction play in the framework of health and obesity prevention?

Dr. Barry Sears – I use the 80/20 rule with regards to weight loss. 80% of your success will come from the diet and the other 20% coming from the other factors. Once you reach your desired weight (really desired per cent body fat) the balance of those other factors becomes more like 50/50.

JP – You’ve co-authored a few studies that point out differences and similarities between ketogenic diets and low carbohydrate diets. What were your conclusions based on those experiments? (6,7)

Dr. Barry Sears – Ketogenic diets (like the Atkins diet) increase cellular inflammation. Non-ketogenic (like the Zone Diet) reduce cellular inflammation. The body requires a certain level of low glycemic load carbohydrates for optimal brain function. A ketogenic diet has more protein than carbohydrate, a non-ketogenic diet has more carbohyrate than protein. The Zone Diet contains slightly more low glycemic load carbohydrates than protein, that’s why it is difficult to characterize it as a high-protein diet. A better description would be a moderate carbohydrate, moderate protein, and moderate fat diet. Who could argue with that?

JP – In 2007, you examined the relative merits of some of the most popular diets (Atkins, LEARN, Ornish and Zone) in relation to weight loss and “related risk factors” in overweight premenopausal women. Any surprises there? (8,9)

Dr. Barry Sears – Weight loss is composed of water loss, muscle mass loss, and fat loss. The Zone Diet has been clinically proven to be the most effective in fat loss. Any diet that restricts calories will cause the same amount of weight loss, but highly variable fat loss.

In the second part of our Q&A session, Dr. Sears will address inquiries pertaining to nutritional supplements and omega-3 fatty acids; controversial foods including artificial sweeteners, coffee, red wine and soy; ways of avoiding “The Perfect Nutritional Storm” and his new line of Zone-friendly food products. I think you’ll find his philosophy and research-based evidence quite compelling. The second installment of my interview with Dr. Sears will be posted here next Wednesday.

Be well!

JP