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What Is the Zone Diet?

Formula Zone Review Board
By Formula Zone Review Board

If you’ve ever heard of the Zone Diet, you may be wondering what it’s all about. Dr. Barry Sears designed this diet to reduce inflammation, aid in weight loss, improve health, and increase the quality of life.

As a health expert with years of experience researching and experimenting with health plans, I have determined the quality of many different diets.

In this article, I will cover several characteristics of the Zone Diet:

  • Nutritional quality
  • Health benefits
  • Followability
  • Affordability
  • Contribution to weight loss

What exactly is the Zone Diet, and how do you follow it? Keep reading to learn more.

The Zone Diet

When following the Zone Diet, you would eat a specific amount of each macronutrient during your meals. The guidelines suggest eating 30% protein, 30% fats, and 40% carbohydrates.

You are to select lean proteins and primarily monounsaturated fats. The carbohydrates you choose need to have a low glycemic index to slow down the release of sugar in your bloodstream. Low GI foods reduce your hunger levels.

What Is the Zone?

The Zone is a physiological state where you have optimized your TG/HDL ratio, HbA1c levels, and AA/EPA ratio. The ideal value for each is <1, 5%, and 1.5-3, respectively. 

Reaching the Zone means you have controlled your liver’s insulin resistance, the amount of advanced glycosylated end-products (AGE) connected to your blood glucose, and your body’s diet-related inflammation.

Dr. Barry Sears claims that dietary inflammation causes you to age faster, get sick, and gain weight. You can control these clinical markers through diet, omega-3 supplements, and polyphenols. 

The Zone Diet guidelines suggest getting these indicators measured over a 3-month period. You can also use the Zone Labs Cellular Inflammation Test.

How to Follow the Zone Diet

When designing your plate, you will want to make ⅓ of your plate lean protein and ⅔ carbohydrates. Then, accessorize with some monounsaturated fat. You want 30% of the calories to come from protein, 30% from fats, and 40% from carbs.

Some suggested foods include:

  • Protein: skinless white-meat poultry, low-fat dairy, egg whites, lean red meat, fish, shellfish, tofu
  • Fats: olive oil, nuts, avocado, tahini, peanut butter
  • Carbohydrates: colorful and non-starchy vegetables, low-sugar fruits, low GI grains

While the Zone Diet has recommendations, it does not ban any foods. However, you should avoid:

  • Sugary fruits and vegetables
  • Refined carbohydrates
  • Foods and drinks with added sugar
  • Sugar-free sodas
  • Starchy vegetables
  • Tea and coffee

According to the Zone Food Pyramid, you should eat mostly vegetables, then fruits, then lean proteins, then monounsaturated fats, and lastly, grains and starches.

It also recommends that you take two anti-inflammatory supplements. These are purified polyphenol and ultra-refined omega-3 fatty acids.

Counting Calories and Macronutrients

You can easily follow this diet by portioning your plate with the above recommendations. However, you can take the advanced approach by using the Zone Food Blocks

The number of Zone Food Blocks you eat daily depends on your height, weight, sex, activity level, hips, wrist, and waist size. These factors determine your approximate body fat percentage. 

Your main meals contain 3-5 blocks, and snacks have one. The calculator will tell you how many blocks you should eat daily. You can determine how many blocks you have eaten following these conversions

  • 1 protein block = 7 grams = 28 calories
  • 1 fat block = 3 grams = 27 calories
  • 1 carbohydrate block = 9 grams = 36 calories

If you are eating animal-based proteins, you would consider each fat block to have 1.5 grams of fat.

This method involves food measurement and tracking. Counting calories can accelerate weight loss, but it can negatively impact daily activities due to its stressful and time-consuming nature. If you view calories as objective data points, you may not struggle with this task.

Evaluating the Zone Diet

By evaluating the reported claims of the Zone Diet, we can determine if it is worth following.

Nutritional Quality

The Zone Diet supports eating a high volume of fruits and vegetables. Increasing fruit and vegetable consumption can prevent multiple conditions and diseases, including: 

  • Cancer
  • Heart disease
  • Stroke
  • Cataracts
  • Hypertension
  • Chronic obstructive pulmonary disease
  • Diverticulosis

Furthermore, lean protein has many benefits, such as:

  • Nitrogen balance
  • Weight management
  • Increased satiety
  • Muscle recovery and growth
  • Improved body composition
  • Increased intestinal calcium absorption
  • Enhanced glycemic regulation
  • Improved bone health

Lastly, one can experience several health benefits from eating monounsaturated fatty acids:

  • Reduced cardiovascular risk
  • Optimized cholesterol levels
  • Reduced insulin requirements
  • Decreased plasma concentration of insulin and glucose

Also, it suggests reducing added sugars and processed foods, which can improve the bioavailability of nutrients.

However, the calorie calculations based on the Zone Food Blocks can be alarmingly low. I plugged in my measurements (125 pounds, 68.5 inches, 26-inch abdomen, 38.5-inch hips, and moderately active). 

It suggested that I eat 11 of each block, which would result in approximately 1,001 calories. This value is significantly lower than my total daily energy expenditure (2,154 calories per day) and would not prove sustainable or healthy. I would have extremely low energy levels by following these recommendations.

Reported Health Benefits

Many of the claims made by Dr. Sears have little scientific backing.

The Zone Diet resembles the Mediterranean diet, which is proven to reduce inflammation. However, the Zone Diet requires more studies to show that it reduces inflammation as well as it claims. For instance, the significant calorie reduction from the diet exhausts athletes faster, so it does not improve performance.

One study compared the Zone Diet to one with 60% carbs, 25% fat, and 15% protein. Those following the Zone Diet did lose more weight, but there were no significant differences in blood levels of cholesterol, sugar, and fat. This study suggests that the differences in the blood values could be from the polyphenol and omega-3 supplements.


Since the Zone Diet does not strictly forbid any food groups, it proves more followable than many other diets. Low-carb diets can be challenging to stick to at first, especially if you are used to eating high-carb. By allowing for some wiggle room, dieters are more likely to follow through.

Also, you do not need to count calories if you don’t want to. You can choose to eyeball the amount of each macronutrient you put on your plate and eat until satisfied. If you would like, you can count calories and macronutrients to stay within the recommended macronutrient levels. 

However, I recommend that you use a separate TDEE calculator to figure out how much you should eat. For some people, the provided calculator may work. Nevertheless, the diet may not prove sustainable for all sizes.

Eating below your basal metabolic rate can reduce muscle mass, slow fat loss, cause fatigue, and decrease endurance. You may plateau in weight loss and feel terrible doing it, so you will be less likely to stick to the diet.


The Zone Diet focuses on simple, whole foods. You do not need to buy organic, grass-fed, pasture-raised, gluten-free, or any other “special” type of food. This aspect improves the cost-effectiveness of the diet.

In many places, you may find that processed foods are more affordable and convenient than whole ones. If you find yourself in this situation, you may have trouble following the Zone Diet.

Since it is a relatively flexible diet, you can try to buy as many whole foods as you can afford and eat processed options on occasion. As long as you strive to eat well when possible, you can still follow the Zone Diet.

Furthermore, you do not need to buy a monthly subscription or meal plans to follow this diet. You can choose to buy the book, but you do not need it.

Contribution to Weight Loss

You are highly likely to lose weight when following the Zone Diet. By reducing added sugars, calorically-dense foods, and processed items, you can reduce the calories you consume significantly.

Protein is known to satiate people’s hunger, and following a high protein diet like this one can benefit weight loss and management. Also, high protein diets can preserve muscle mass when losing fat.

Combining protein with healthy fats and fibrous fruits and vegetables can also reduce the volume of food you need to consume to feel full.

When calorie counting on the Zone Food Block method, you can more precisely determine how much weight you will lose each week. Once again, ensure you eat enough to maintain your physical activity levels on this plan. You may need to increase the amount of food from the suggested values to keep the diet sustainable.

Final Thoughts

If you feel comfortable following a moderate-carb diet, you might benefit from the Zone. It is nutritionally sound and provides many health benefits.

Keep in mind that there is no one-size-fits-all diet. What works for someone may not work for you. Also, you can eat the foods that the Zone Diet wants you to restrict while still living a healthy lifestyle.

Overall, feel free to experiment with this diet. If you want to maximize the health benefits, ensure you include the suggested supplements in your routine.