Low-Carb Diet Research and News

Spending A Week In The Zone with Barry Sears, Ph.D.

Special Program
Monday, March 13, 2000 7:00 PM EST

By Barry Sears, PhD

Moderator: We're about to start our chat with Dr. Barry Sears for "A Week in the Zone"

Welcome to WebMD Live's Special Events Auditorium. Today we are speaking with Dr. Barry Sears about The Zone Diet, week one.

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Thank you Dr. Sears for being with us today. 

Do you have any last comments you'd like to give to our audience today? What is "The Zone" diet program?

Dr. Sears: The Zone Diet program is all about keeping the hormone, insulin, within the Zone, not too high, but not too low. In essence, it is treating food with the same respect that you would treat any prescription drug. The program was developed nearly 20 years ago for treating heart disease in Type II diabetes. Both conditions are characterized by elevated levels of insulin and the only drug known to science that can effectively lower insulin on a daily basis is called "food."

Moderator: There seems to be some controversy about the Zone diet, that it's based on too much protein .. can you respond to that?

Dr. Sears: Yes. One of the great misconceptions about the Zone diet is that it's a high protein diet, which it is not. The maximum amount of low fat protein a person should consume at a meal is between 3-4 oz., an amount that virtually every nutritionist would concur with. Also, on the Zone diet, it's exceptionally rich in carbos, but primarily fruits and vegetables. In fact, the Zone diet recommends consuming 10-15 servings of fruits and vegetables per day. That is nearly 3 times what is recommended by the US Government.

Moderator: The Zone food pyramid differs from the pyramid of the US government ...

Dr. Sears: The base is still carbs, but now it's composed primarily of fruits and veggies, followed in lesser amounts by low fat protein, and this can be animal or vegetable, and then followed by small amounts of heart healthy monounsaturated fats, and finally to be used in moderation, high density carbs such as grains, starches, bread, and pasta. The goal of that type of food pyramid is to orchestrate the appropriate hormonal responses that will generate a stabilization of insulin levels.

Moderator: How is food like a drug?

Dr. Sears: Because food affects hormones, and hormones are hundreds of times more powerful than any drug. This means that at every meal you consume, you are basically probably taking the most powerful drug that you will ever encounter in your lifetime if you only know how to construct a meal to make the most appropriate hormonal response,.

Moderator: How did you come about this program?

Dr. Sears: Really to treat my own genetic history ... everyone on the male side of my family dies of a premature heart attack. I realized I could not change my genes, but the expression of them. I realized 20 years ago that the primary cause of heart disease was not high cholesterol, but high levels of insulin. And that set me on a 20 year journey to understand the appropriate balance of protein, carbohydrate and fat to help orchestrate these hormonal responses.

Moderator: Doctor, do you have scientific research, double blind studies, etc., that vindicate the Zone Diet?

Dr. Sears: It's hard to have double blind studies when dealing with food, but there are controlled studies published over the last year which have validated the Zone concept. The first study was done by Harvard Medical School published in the Journal of Pediatrics demonstrating that a single Zone meal compared to a traditional meal of the same calories, the Zone meal would have a dramatic improvement on insulin output, stabilization of blood sugar, and increased satiety and decreased number of calories consumed at the next meal. Australian investigators in 1998, published in the journal of Diabetes Care, demonstrated that after 3 days of the Zone Diet, insulin and insulin resistance were dramatically improved in both overweight and Type II Diabetic patients. Another study in 1999 in the Journal of the International Journal of Obesity demonstrated that patients on a Zone Diet were compared to a standard diet of equal caloric intake, the Zone diet generated nearly twice the fat loss as compared to the other standard diet.

Moderator: Doctor, do you have research on how the Zone Diet effects cholesterol levels and blood pressure?

Dr. Sears: Yes, with cholesterol it's how it effects the enzyme HMG Co-A Reductase. This is the same enzyme that all of the cholesterol lowering drugs work on. This enzyme is activated by insulin and deactivated by the other hormone called glucagon. Insulin is produced primarily in response to carbos at a meal and glucagon is produced primarily by the protein content at a meal, thereby controlling the ratio of protein to carbohydrate allows you to fine tune the insulin output at a particular meal and, in the process, control the output of cholesterol by the liver.

Moderator: So, you're saying that research is saying that people in the Zone have lower cholesterol levels?

Dr. Sears: Yes. However, this is not the primary predictor for heart disease. The recent work from Harvard Medical School has demonstrated that the ratio of triglycerides to HDL cholesterol is a much more powerful predictor of heart disease than is total cholesterol levels or even the levels of bad cholesterol -- the so-called LDL cholesterol. The reason why that ratio of triglycerides to HDL cholesterol is so predictive is because it's a surrogate marker for elevated insulin.

smileyd_WebMD: I've been interested in going on this diet, how should I start?

Dr. Sears: All you need is one hand and one eye. (laughs) And, all the rules you need are the following .. First rule, never consume any more low-fat protein than you can fit on the palm of your hand. And, before you get too excited that's also the thickness of the palm of your hand. That would be about 3 oz. of low fat protein for a female and about 4 oz. of low fat protein for a male. Now, take your plate at every meal and divide it into three sectors, on one side you put some low fat protein, no bigger or thicker than the palm of your hand, the other 2/3rds you fill till it's overflowing with vegetables and fruit, and you add a dash of heart healthy monounsaturated fat, which can be almonds, olive oil, or even guacamole, and now you have a perfect Zone Meal to keep insulin levels under control for the next 4-6 hours.

smileyd_WebMD: What type of protein is best?

Dr. Sears: The best type of protein is low fat protein for two reasons.  One, we want to keep the amount of saturated fat as low as possible, and two, we want to add back fat of our choice, heart healthy monounsaturated fat so we are in control of the fat content in our diet. Low fat protein sources would include chicken, turkey breast, fish, egg whites, tofu, and soy bean meat substitutes.

smileyd_WebMD: What do you think about all the powdered proteins compared to, let's say, a lean steak?

Dr. Sears: In many ways, the powdered proteins are preferable because they are devoid of any fat whatsoever and now you can add back fat of your choice with greater precision.

pd919_MSN: Can you give an example of a typical meal on the Zone Diet?

Dr. Sears: I'll do one better, I'll give a typical day on the Zone Diet for an average female. This average female would start the day off with a six egg white omelets to which she would add two tsp. of olive oil. She'd add 2/3 of a cup of slow cooked oatmeal. Because the more processed the oatmeal is, the faster it will enter your bloodstream and the greater effect it will have on your insulin response. Now finish the breakfast off with a cup of strawberries. Now for lunch, a tuna salad consisting of one head of lettuce, two cucumbers, three bell peppers, a 1/4 cup of chick peas, 4 oz. of tuna fish with a little mayo and a piece of fruit for dessert. Now, at 5pm, we'll have a hormonal snack consisting of 1 oz. of sliced turkey and a 1/2 piece of fruit. For dinner, she'd have 5 oz. of salmon, 4 cups of steamed veggies, and a cup of mixed berries for dessert. And, before bed, a glass of wine and a piece of cheese.

Moderator: Dr. Sears, how many calories is this a day?

Dr. Sears: That would be about 1200 calories a day, though most females would have a difficult time eating all the food. The average for males would be about 1500 a day, but he too would have a difficult time eating it all because once you switch to eating lower density carbs it becomes difficult to eat all of the food you have to.

Moderator: Dr. Sears, can you give us a breakdown, how much fat, how much protein, how much carbs?

Dr. Sears: For the average American female, about 75 grams of protein a day. That's about what Americans are already consuming. The government recommends in the range of 60. The carbo content would be between 100 and 110 grams. This is about half that recommended by the government, but once one is eating lower density, it's a very large volume, and fat would be in the range of 40 grams, but almost entirely composed of monounsaturated fat. 

For the average American male, he'd be consuming about 100 grams of low fat protein per day, and about 130-140 grams of carbohydrate, primarily composed of fruits and veggies, 10-15 servings of them, and approx. 50 grams of monounsaturated fat. In terms of dietary recommendations, these are not outlandish amounts. The only difference between the Zone Diet and most diets put forward by the US Government or the Heart Association is that you're not consuming as many carbs and by doing so, not producing as much insulin. But at all times you're always consuming more carbohydrates than protein.

Moderator: We're going to be spending a week in the Zone with you Dr. Sears.

Moderator: What would you recommend someone do in the kitchen?

Dr. Sears: I'd recommend cleaning out your cupboards of all of the high density carbs for the next week, this means taking out the pasta, rice, the bread, bagels and putting them in some place where you're not likely to venture in the next week. Your primary source in the next week will come from fruits and vegetables, just like the way your grandmother told you to eat 2 generations ago. Now, with all this new empty space, we want to fill it with staples for our week in The Zone. And, this would be primarily fruits and veggies and low fat protein.

Dr. Sears: So, for the next week we want to have you go to the supermarket and pick up the foods you really like to eat .. the fruits and veggies you really like to eat, and stop by the deli to get some low fat protein to put in the refrigerator. With that, we now have our food pharmacy complete.

pd919_MSN: What fruits and veggies should I try to avoid and what if you don't like seafood?

Dr. Sears: Okay. The fruits and veggies .. fruits tend to be the tropical fruits .. papaya, mango, watermelon and other melons ... why? They enter the bloodstream at a rapid rate. The best fruits turn out to be berries. Relative to the veggies, we want to keep down if not avoid ... very minimal amounts of corn and also carrots, because both of these will also enter the bloodstream as carbohydrates very rapidly. This is not to say that you can never eat them again, just use them, as condiments, in moderation. Olive Oil, some almonds, and if need be, some avocados. Macadamia nuts are the best.

Moderator: Different people have different bodies. Can the Zone diet really work for everyone?

Dr. Sears: The answer is yes. Even though everyone has their own unique biochemistry, the key for the Zone Diet is tuning it to your biochemistry that allows you to maintain insulin within that Zone. Just as we'd adjust a carburetor of a car, we're trying to find the right balance of protein to carb for your particular biochemistry and once we have that, maintain that on a lifetime basis.

Moderator: Thanks for joining us, Dr. Sears!

Dr. Sears: My pleasure!

Moderator: We look forward to spending a "Week in the Zone" with you.  Most people can get a copy of your book "A Week in the Zone" from Barnes & Noble ....

Dr. Sears: That's correct.

Moderator: Let me make it clear that WebMD does not particularly endorse any diet, but we leave it to you to make your own choices.

Thank you Dr. Sears for chatting with us today. Please join us tomorrow, Tuesday, March 14th at 2:30pm Eastern Standard Time for another chat with Dr. Barry Sears on "Spending a Week in The Zone." Thank you and good day.

Dr. Sears: Thank you very much!