In recent radio interviews, I am often asked, “Has anything changed about the Zone Diet over the past 20 years?” The answer is both no and yes.
The no answer is that the basic outline of the Zone Diet has not changed at all in the past 20 years. Furthermore, in every carefully controlled clinical study, the Zone Diet has been consistently shown to have the greatest anti-inflammatory effects of any diet ever studied, even with equivalent weight loss (1-3).
The yes answer is because there is a continual flow of new discoveries on the molecular basis of nutrition and its relation to inflammation. When there is enough new data on these advances, I then write another book that helps to expand the basic concept of the Zone, first mentioned in 1995 in my original book, The Zone.
For example, the Zone Diet is a calorie-restricted diet, but one without hunger or fatigue due to improved hormonal control. My 1999 book, The Anti-Aging Zone, simply went into greater detail of the mechanisms of calorie restriction and how those mechanisms slow down the rate of aging.
In 2002 I wrote The OmegaRx Zone, which essentially started the fish oil revolution in America. Omega-3 fatty acids are among the central core themes in The Zone, since they help control inflammation. In fact, anyone who actually read The Zone in 1995 would know that I developed the Zone Diet to make omega-3 fatty acids more efficient in controlling inflammation. The OmegaRx Zone updated that earlier information with new insights into the use of high-dose fish oil to control both the initiation and resolution of inflammation. That’s why the book is subtitled “The Miracle of High-Dose Fish Oil”.
Controlling inflammation is the central theme of The Zone. That’s why there are so many chapters related to eicosanoids, the hormones that regulate inflammation. The Anti-Inflammation Zone, published in 2005, simply updated those basic anti-inflammatory concepts with new accumulated research.
Obesity has always been more complex than we are led to believe. Toxic Fat published in 2008, went a great distance to explain new insights in the relationship between inflammation and obesity. Again, I was simply extending my initial insights written about in The Zone.
The Mediterranean Zone was written in 2014 to describe the breaking information on the role of polyphenols and human health. Virtually nothing was known about polyphenols when I wrote The Zone in 1995, however the primary carbohydrates (fruits and vegetables) used in constructing the Zone Diet were also those also rich in polyphenols. This book might be better described as “The Color of the Zone”.
And my next book, The Skin Zone, will describe the growing importance of the regulation of the microbes in our gut to reduce inflammation.
I guess I could have one new edition of The Zone after another to include newest supporting science behind my original concepts. But that would mean the 2014 edition of The Zone would be close to 1,000 pages.
So my answer to the question has anything changed about the Zone Diet is that the concept of the Zone and the use of the Zone Diet to reach that Zone has remained consistent for 20 years and probably will for the next 200 years.
In addition to that basic question, here are some additional questions I am often asked in interviews.
What is the Zone?
The Zone is real metabolic state measured by several clinical markers routinely used by Harvard Medical School. If you are in the Zone, then inflammation levels in the body are balanced so that you are less likely to develop chronic disease and more likely to live a longer life.
Do calories count?
As I pointed out in my book, Mastering the Zone, they do and they don’t. Calories do count because you can’t lose excess fat unless you are in calorie deficit situation. The Zone Diet is a calorie-restricted diet but without hunger or fatigue. When you can see your abdominal muscles, then consider adding more calories back to your current Zone Diet as monounsaturated fat. Calories don’t count if you are not getting adequate protein to maintain your muscle mass or they are not balanced so your hormones are not balanced. If your hormones aren’t balanced, then you will always be hungry and fatigued on any calorie-restricted diet.
What do you think about saturated fats?
I believe that they should be minimized in the diet, especially palmitic acid. We now know that palmitic acid binds to specific receptors that induce inflammation. Since palmitic acid is the most abundant saturated fat, it just makes sense to reduce all saturated fats in the diet thereby reducing palmitic acid levels.
What do you think about omega-6 fats?
You need some, probably 0.5% of calories but no more than 1-2%. Current intake of omega-6 fatty acids in the U.S. is 8%. What makes omega-6 fats so dangerous is when they are combined with high levels of insulin, you accelerate the formation of arachidonic acid (AA) that is the building block for the hormones that drive inflammation. This was the central theme of The Zone. On the other hand, monounsaturated fats are non-inflammatory and omega-3 fats (especially eicosapentaenoic acid or EPA) are both anti-inflammatory and have pro-resolution properties.
How do you find the right balance of omega-6 to omega-3 fatty acids?
The AA/EPA ratio in the blood will tell you. It should be between 1.5 and 3. The current AA/EPA ratio in Americans is 18. That is indicative of high levels of inflammation, the result of the combination of too many omega-6 fatty acids and elevated insulin levels coupled with not enough omega-3 fatty acids in the diet.
What does a typical day of eating on the anti-inflammatory Zone Diet look like?
If there is anything “magical” about the Zone Diet, it is remarkable that you need few calories to perform at high levels if you are using the appropriate balance of macronutrients at every meal. The overall goal of the Zone Diet is to consume about 1,500 calories per day for an average male and 1,200 calories for an average female with 1:2:3 ratio of fat to protein to carbohydrate at every meal. If done correctly, you will never be hungry or fatigued as you are maintaining stable blood sugar levels. This means at each meal you need to eat about 25-30 grams of high-quality protein to induce satiety with the right balance of fat and carbohydrate. For the average male three meals and a snack would provide about 50 grams of fat, 100 grams of low-fat protein, and 150 grams of low-glycemic carbs (primarily non-starchy vegetables and limited amounts of fruit, both rich in fermentable fiber) while consuming about 1,500 calories. Although this seems like a limited number of calories, if you balance macronutrients correctly at every meal, you should never be hungry or fatigued because you are controlling your hormones resulting in optimal satiety and blood sugar control.
Here are simple examples of a typical day of Zone meals and snacks for the average male.
- Breakfast: 8 egg-white omelet with, 2/3 cup of slow cooked oatmeal, 1 heaping tablespoon of slivered almonds, and ½ cup of blueberries.
- Lunch: 4 oz. of grilled chicken with 3-4 cups of cooked vegetables and 1 tablespoon of extra-virgin olive oil.
- Dinner: 6 oz. of grilled fish with 3-4 cups of cooked vegetables and 1 tablespoon of extra-virgin olive oil. Add another ½ cup of berries for dessert.
- Snack: Two hard-boiled eggs with the yolks removed and filled with ¼ cup of hummus.
I don’t think anyone would consider that to be a day of dietary deprivation especially if you are never hungry or tired.
Is fish oil the most important supplement that we should be taking?
It is because Americans simply don’t eat enough fatty fish that contain omega-3 fatty acids. You need a minimum of 2.5 grams per day of long-chain omega-3 fatty acids to help control inflammation. That is about what the Japanese consume. Current American intake of long-chain omega-3 fatty acids is 125 mg or 95% less than my minimum recommendations. Furthermore, Americans have to consume even more omega-3 fatty acids to counterbalance their excessive omega-6 intake. Unfortunately, all fish (especially the fatty ones rich in omega-3 fatty acids) are contaminated with mercury, PCBs, and other toxins, which is still another problem to overcome. This unfortunate fact can be overcome by using highly refined omega-3 concentrate like OmegaRx®.
Why do you only recommend low-fat protein?
You are trying to keep your total fat intake to 50 grams per day. Most of that fat should be monounsaturated fat since it is non-inflammatory. By using low-fat protein, you can control the type of fat thus keeping the intake of both omega-6 fats and palmitic acid to a minimum.
Is red meat something we should be eating in your opinion?
I would recommend eating wild, lean red meat or at least grass-fed lean beef at least once a month to get adequate levels of vitamin B12 but probably not more than twice a month.
On the topic of aging, do you think that a diet rich in fats benefits the aging process at all?
Yes and no. A diet rich in omega-3 fats will reduce inflammation, which is the primary driver of aging, but you also need it combined with calorie restriction as I described in The Zone and in more detail in The Anti-Aging Zone. However, calorie restriction only works if you are never hungry and never fatigued. That can only be achieved by balancing macronutrients at every meal as I first described in The Zone in 1995.
And what about anti-aging genetic tests, to what extent can they help us live longer and better?
I believe they are relatively worthless at this time. Markers of diet-induced inflammation are better indicators of future health. All you need are the clinical markers that define the Zone. These are (a) the AA/EPA ratio, (b) TG/HDL ratio, and (c) your level of HbA1c. If these simple blood markers are within my recommended ranges, then you are keeping inflammation under control.
Is exercise a big part of the Zone Diet?
Exercise has lots of benefits, but weight loss is not one of them. The best exercise is not to sit for more than 15 minutes. The next best exercise is interval training three times a week.
How about ketogenic diets?
I have very little enthusiasm for ketogenic diets because they induce abnormal hormonal responses. According to research from Harvard Medical School, ketogenic diets depress thyroid levels and increases cortisol (4). Furthermore, I demonstrated in the American Journal of Clinical Nutrition in a 2006 article that the Zone Diet is superior to a ketogenic diet under controlled dietary conditions when calories and protein levels are held constant.
Are there situations in which you would suggest a lower-fat or lower-protein and higher-carb diet and vice versa?
The one condition would be cancer. I would dramatically increase both omega-3 fats to increase resolution of inflammation that drives cancer metastases. My recommendations would be at least 15 grams of EPA and DHA per day. Next, I would dramatically increase the use of polyphenol extracts to activate AMP kinase to inhibit mTOR activity that is a secondary driver of cancer. Here I would recommend about 2-5 grams of purified polyphenol extracts per day. I would also lower the protein levels (particularly the amino acid leucine) to further reduce mTOR activity and finally decrease the glycemic load (by eating only non-starchy vegetables) to stay just beyond ketosis all with the least number of calories without hunger or fatigue.
Do you recommend one diet for everyone?
No, but I do recommend one set of blood tests for everyone. These tests define the Zone therefore indicating that inflammation is being controlled. How you get there doesn’t matter. I just think the Zone Diet is the easiest way to get to the Zone and stay there for a lifetime.
- Pereira MA, Swain J, Goldfine AB, Rifai N, and Ludwig DS. “Effects of a low-glycemic load diet on resting energy expenditure and heart disease risk factors during weight loss.” JAMA 292:2482-2490 (2004).
- Pittas AG, Roberts SB, Das SK, Gilhooly CH, Saltzman E, Golden J, Stark PC, and Greenberg AS. “The effects of the dietary glycemic load on type 2 diabetes risk factors during weight loss.” Obesity 14:2200-2209 (2006).
- Johnston CS, Tjonn SL, Swan PD, White A, Hutchins H, and Sears B. “Ketogenic low-carbohydrate diets have no metabolic advantage over non-ketogenic low-carbohydrate diets.” Am J Clin Nutr 83: 1055-1061 (2006).
- Ebbeling CB, Swain JF, Feldman HA, Wong WW, Hachey DL, Garcia-Lago E, and Ludwig DS. “Effects of dietary composition on energy expenditure during weight-loss maintenance.” JAMA 307:2627-2634 (2012).