What Is the Zone Diet?

In This Article

The Zone diet focuses on balancing your food intake precisely between protein, carbohydrates, and fats in an effort to provide your body with exactly the fuel it needs.

It's not specifically a weight-loss diet, although you may lose weight on the program, especially if you start out overweight and also increase your activity level. Instead, the Zone diet is billed as a diet intended to get and keep your body operating at peak efficiency, and to lessen your odds of developing dangerous health conditions such as heart disease and cancer.

The diet contains a wide variety of healthy foods. Unfortunately, it also eliminates some foods that most experts consider to be good additions to a healthy diet, including grain-based products and legumes.

"By structuring meals with 1/3 protein, 2/3 carbohydrates, and a little fat, the Zone Diet promises to reduce inflammation and shed pounds. Experts question some choices on the “unfavorable foods” list (like certain fruits), but agree that the diet is relatively balanced overall."

—Chrissy Carroll, RD, MPH

Background

The Zone program is designed to teach you to use food to reach the metabolic state where your body and your mind operate at peak efficiency.

According to Enter the Zone author Barry Sears, M.D., "In the Zone, you'll enjoy optimal body function: freedom from hunger, greater energy, and physical performance, as well as improved mental focus and productivity."

As an added benefit, Dr. Sears writes, you'll be less likely to suffer from infectious illnesses such as colds and flu, and also will be less likely to develop serious chronic illnesses such as heart disease and cancer.

To gain these benefits, the Zone diet calls for consuming a precise amount of protein daily that's based on your percentage of body fat and your activity level. You'll also eat a set amount of carbohydrate-based foods, favoring certain fiber-rich fruits and vegetables over potatoes and grain-based foods such as bread and pasta. Finally, you need to consume fat at every meal.

The idea behind this diet originally stems from Dr. Sears' research into drug delivery technology (he holds major patents for intravenous drug delivery). According to Dr. Sears, the diet balances your body's concentration of a class of hormones called eicosanoids. These hormones play a key role in many human body systems, including the cardiovascular system, the immune system, and the systems that govern how much fat is stored. They also affect your levels of inflammation.

How It Works

When following the Zone diet, you're urged to view food as a potent drug that has a powerful impact on your body and your health—more powerful "than any drug your doctor could ever prescribe," according to Dr. Sears. Every meal and snack should have the desired balance of macronutrients—protein, carbohydrates, and fat—that produce an appropriate and favorable hormonal response.

First, you'll determine your total daily protein requirement. That amount of protein should be spread evenly throughout the day so that every meal you eat contains a roughly equal amount of protein. Every snack also should contain a smaller amount of protein.

Then, you'll balance your protein with carbohydrate foods—again, every meal and every snack should balance your protein with carbohydrate, with a ratio of around one-third protein to two-thirds fat.

Finally, you need to eat some fat at every meal. Fat in your diet helps to tell your body that you're full and don't need to eat any more food, and it serves as an important building block of the eicosanoid hormones that the Zone diet is attempting to promote.

Every meal and every snack you eat when following the Zone diet should contain very specific amounts of protein, carbs, and fat.

What to Eat

Compliant Foods

  • Skinless chicken breast and turkey breast

  • Lean pork and lean lamb

  • Most seafood (tuna, shrimp, salmon, and cod)

  • Egg whites

  • Tofu

  • Low-fat cottage cheese

  • Protein powder

  • Most green vegetables (asparagus, broccoli, and zucchini)

  • Cauliflower and cabbage

  • Green leafy vegetables (lettuce and spinach)

  • Celery and cucumbers

  • Most fruit (apples, pears, berries, and grapes)

  • Olives

  • Mayonnaise

  • Olive oil

  • Macadamia nuts

  • Natural peanut butter

  • Avocado

  • Oatmeal (slow-cooking)

Non-Compliant Foods

  • Egg yolks

  • Organ meats

  • Fatty red meat

  • Vegetable shortening

  • Hard cheeses, cream cheese, and sour cream

  • Processed meats (bacon, sausage, salami, and hot dogs)

  • Carb-heavy vegetables (acorn squash, corn, and beans)

  • Carb-heavy fruit (mango, banana, and raisins)

  • Fruit juice

  • All bread and pasta

  • Candy

  • Ice cream

Protein

The Zone diet treats protein as a prescription drug. Once you've determined how much protein you need to eat (based on your fat stores and your activity level), you need to spread your intake of protein throughout the day to keep your levels as even as possible, just as you'd spread a prescribed medication throughout the day.

Since different types of protein affect your body in different ways (protein high in saturated fat, such as fatty red meat, organ meat, and egg yolks, stimulates inflammation and insulin resistance), Dr. Sears recommends sticking with low-fat meats such as chicken and turkey breast, fish, egg whites, and vegetarian protein sources such as tofu.

Fats

Every Zone diet-complaint meal should include fat, since fat helps your body absorb some of the nutrients in your food and also assists your body in creating eicosanoids, the helpful hormones Dr. Sears wants to promote. Although it's possible to get fat from fattier cuts of meat, the Zone diet recommends against this approach, since the fat contained in meat isn't the correct type of fat.

Instead, focus on "good fats," such as olive oil, canola oil, olives, macadamia nuts, and avocados (guacamole is recommended as well). Mayonnaise and light mayonnaise are fine, as well, provided they're made from monosaturated fats and not from egg yolks (the way traditional mayonnaise is made).

Don't overdo the fats. Dr. Sears stresses that the Zone diet is a low-fat diet. The ideal amount of fat is 1 1/2 grams of fat per 1 oz. of poultry or 1.5 oz. of most fish. That's the equivalent of just one teaspoon of olive oil for every three-ounce serving of chicken breast (much less than most of us pour on our salads).

Carbohydrates

Once you know how much protein you should be eating on a daily basis, it's easy to match that to carbohydrates. The Zone diet calls for you to eat 9 grams of carbohydrate for every 7 grams of protein. Recommended carbohydrate-based foods are those with a low glycemic index—that means they raise your blood sugar slowly, rather than quickly.

Dr. Sears recommends most fruits and vegetables as carbohydrate sources, including green leafy vegetables such as spinach, kale, and collard greens, raw vegetables such as peppers, lettuce, and broccoli, cooked vegetables such as eggplant, cabbage, and onions, and fruit such as apples, berries, melon, citrus such as oranges and grapefruit, and peaches.

The Zone diet does not recommend eating any grain-based foods. This includes bread, pasta, crackers, cookies, cake, and cereal. It also recommends against certain starchy vegetables and fruits, including winter squash, beans, corn, potatoes, bananas, mango, papaya, prunes, and raisins. Most fruit juices are off-limits as well, due to their sugar content.

Recommended Timing

The Zone diet focuses heavily on keeping your body in "the Zone." Therefore, the timing of your daily food intake is critical to accomplish the diet's goals.

Specifically, when following the Zone diet you'll eat three meals a day: breakfast, lunch, and dinner. You'll also allow for two snacks. Your meals will be evenly spaced throughout the day. Skipping meals is not recommended, nor is loading up at one meal and eating lightly at another. Just as you balance your food intake between protein, carbs, and fats, you'll balance it time-wise.

Resources and Tips

You need to know how much protein to eat when following the Zone diet, since your protein allotment determines your carbohydrate and fat allotment. The key to determining your daily protein requirement is calculating your lean body mass, and then determining how active you are.

According to Dr. Sears, everyone's daily protein requirement is unique. To calculate yours, first, calculate your percentage of body fat (women measure their height and the difference between their waist and their hips, while men measure their waist and their wrist). Then, you use tables provided by Dr. Sears in his book to calculate total mass and lean body mass.

People who are sedentary only need to consume 0.5 grams of protein per pound of lean body mass to maintain that lean body mass. At the other extreme, people who do heavy weight workouts every day or who exercise twice per day need twice that amount: 1.0 grams of protein per pound of lean body mass.

Between the two extremes lies a continuum, and those following the Zone diet need to determine where they fall on the continuum. People who are more active than average require more protein than average to repair and rebuild muscle that gets damaged during higher levels of physical activity. The diet also calls for people who are overweight to allow themselves more protein, since they require more muscle mass to carry the extra weight.

Modifications

People who are following many other types of diets, such as a gluten-free diet, a vegetarian diet, or a diet that omits certain allergens such as nuts or cow's milk, also can follow the Zone diet with a few modifications:

  • The Zone diet doesn't require animal-based foods, so if you're a vegetarian or vegan, it's not problematic to try the Zone diet. However, you should be aware that multiple vegetarian and vegan staple foods, including grains and beans, are off-limits on the Zone diet due to their high starch content.
  • Since the Zone diet omits all grain-based foods (many of which contain gluten), it's easy to make it gluten-free. Therefore, people who have celiac disease or non-celiac gluten sensitivity may find that this diet fits in well with their weight-loss goals.
  • If you have diabetes, make sure to talk with your doctor before trying the Zone diet. The program is designed to help balance blood sugar, but people with diabetes could run into trouble by eliminating so many common foods at once.

Pros and Cons

Pros

  • Diet is reasonably well-balanced

  • Allows a wide variety of foods

  • Meal planning isn't difficult

Cons

  • Eliminates many healthy food choices

  • Complicated to track

  • May not be best for people with certain health conditions

Pros

General Nutrition

The Zone diet generally follows nutritional guidance that calls for your meals to be mostly carbohydrates, with a smaller amount of protein and a very small amount of fat. Lean proteins are stressed, and the diet encourages you to consume lots of vegetables and fruit. Sugary drinks and other "junk food," such as candy and chips, are eliminated.

Flexibility

Since the diet allows such a wide variety of foods, it's quite flexible. People who have other dietary restrictions should find it relatively simple to adapt. You will need to eat similarly-sized meals three times per day, but many people already eat breakfast, lunch, and dinner, so this won't be a big change. Meal planning also isn't too tricky, since there are lots of food combinations that will work, many with little or no actual cooking involved.

Cons

Specific Nutrients and Fiber

The Zone diet eliminates many healthy food choices, such as whole-grain bread, cereal, and pasta, beans and legumes, and some fruits. You may find it's difficult to get enough dietary fiber on this diet, simply because it places off limits so many good fiber choices.

Complicated Tracking

Although most diets call for you to track something—calories, steps, or fat grams—the Zone diet is especially tricky, since you'll need to count protein, fat, and carb grams all at once, and make sure you consume the right quantities of each.

Certain Health Conditions

Although the Zone diet is touted as one that can help you ward off serious chronic health conditions such as heart disease, diabetes, and cancer, people who already have been diagnosed with those conditions should talk to their doctors about whether the food restrictions in the diet are best for them.

How It Compares

Dr. Sears' book, Enter the Zone, first was published in 1995, and the diet has remained relatively popular over the years. Although the Zone diet gets relatively good marks from nutritionists, it doesn't match up well with dietary recommendations from the U.S. Department of Agriculture (USDA).

The 2019 U.S. News and World Report Best Diets ranks the Zone diet number 23 in Best Diets Overall and gives it an overall score of 3/5.

USDA Recommendations

The Zone diet's recommendations match up with the USDA's nutritional recommendations in some respects, while deviating in others.

The USDA's advice, outlined in the agency's MyPlate tool, call for half a "plate" full of fruits and vegetables per meal, with around 3/5ths of a plate of grains and 2/5ths a plate of lean protein. The protein amounts are similar between the USDA and the Zone diet, but the Zone diet eliminates grain products entirely.

Calorie-wise, the Zone diet matches the USDA recommendations fairly closely, Since the Zone diet is designed more as a way of improving your health (with possible weight loss a bonus, not the goal), it doesn't focus on cutting calories substantially.

Similar Diets

Several weight-loss diets include attributes that are similar to those found in the Zone diet. However, no other diet brings these attributes together in quite the same way.

Paleo Diet

Like the Zone diet, the Paleo diet eliminates grains and most legumes. For both diet programs, the idea behind this rule is that the human body has not evolved to eat large quantities of starchy carbs. However, the Paleo diet calls for more protein than the Zone diet, and generally does not discourage consumption of red meat. It also allows for more fat than the Zone diet, although the types of fats allowed (monounsaturated fats) are similar on both programs.

Mediterranean Diet

At first glance, the Mediterranean diet and the Zone diet might appear quite similar: both encourage consumption of lots of colorful fruits and vegetables, plus fish, lean meats, and healthy oils such as olive oil. But the Mediterranean diet also encourages eating whole grains and legumes, both of which are a good source of fiber.

Anti-Inflammatory Diet

The Zone diet is designed in part to combat inflammation, which makes it similar in concept to the anti-inflammatory diet, also created to calm chronic inflammation. Both diets focus on healthy fats and limit sugar, processed meats such as hot dogs and bacon, and refined grains. The anti-inflammatory diet also eliminates many of the same foods as the Zone diet, including: wheat-based foods, fatty meats, and packaged snack foods. Still, both diets can be complicated due to the complex rules that must be followed.

A Word from Verywell

The Zone diet, although it's more than two decades old, continues to have a devoted following. Multiple sites publish Zone-compliant recipes (which can be helpful in designing meals to meet the stringent protein-carbs-fat requirements of the diet).

When following the diet, you're unlikely to go hungry, although you may find yourself craving sweets and grain-based carbs. Although it's not designed specifically as a weight-loss diet, you also can lose weight on the Zone diet.

However, you should keep in mind that it's easy to miss out on fiber on this diet, and try to incorporate as many Zone-compliant higher-fiber fruits and vegetables as possible into your overall meal plans. In addition, anyone with a chronic health condition such as diabetes or cardiovascular disease should speak with their doctor before starting the Zone diet.

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Article Sources

  • Sears, B. and Lawren, B. (1995). Enter the Zone. New York, NY: Regan Books.