May 28, 2021

The Zone Diet - a complete overview

Die Zone Diät – ein vollständiger Überblick

The Zone Diet has been popular for several decades. It encourages its followers to consume a certain amount of protein, carbohydrates and fat at each meal to reduce inflammation in the body, among other health benefits.

However, critics have questioned some of these health benefits.

This article provides a detailed overview of the Zone Diet, including what it takes to follow it and what the pros and cons are.

What is the Zone Diet?

The Zone Diet instructs its followers to follow a specific ratio of 40% carbohydrates, 30% protein and 30% fat.

Carbohydrates should have a low glycemic index, which means that they ensure a slow release of sugar into the bloodstream to allow for longer satiety. Protein should come from lean sources and fat should consist mainly of monounsaturated fatty acids.

The Zone Diet was developed more than 30 years ago by Dr. Barry Sears, an American biochemist. His bestseller "The Zone" was published in 1995.

Dr. Sears had developed this diet after the early loss of a family member to a heart attack and felt that he too was at increased risk until he found a way to combat this.

The Zone Diet claims to reduce inflammation in the body. Dr. Spears believed that inflammation is the reason why people gain weight, get sick and age faster.

Advocates of this diet claim that once you reduce inflammation, you lose fat at the fastest rate possible, slow down aging, reduce your risk of chronic disease and improve your performance.

What do you need to do to follow the Zone Diet?

The Zone Diet has no specific phases and is meant to be followed for a lifetime. There are two ways to follow this diet: The hand-eye method or the use of Zone food blocks.

Most people start with the hand-eye method and later move on to Zone food blocks as they are more advanced. You can switch back and forth between the two methods if you wish, as both have their own benefits.

The hand-eye method

The hand-eye method is the easiest way to start the Zone diet. As the name suggests, your hand and your eye are the only tools you need to get started - although it is also recommended to wear a watch to keep an eye on when you should eat.

In this method, your hand serves multiple purposes. You use it to determine your portion sizes. Your five fingers remind you to eat five meals a day and never go longer than 5 hours without eating.

At the same time, you use your eye to estimate the portion sizes on your plate. To create a Zone-friendly plate, you first need to divide your plate into three thirds.

One-third low-fat protein: One-third of your plate should be filled with a low-fat protein source that is roughly the size and thickness of the palm of your hand.
Two thirds carbohydrate: Two thirds of your plate should be filled with low glycemic index carbohydrates.
A little fat: Add a dash of monounsaturated fat such as olive oil, avocado oil or almonds to your plate.

The hand-eye method was developed as an easy way for beginners to follow the Zone diet. It is also flexible and allows you to eat in a restaurant while following the Zoe Diet by using your hand and eye to choose options that fit the Zone recommendations.

The Zone food block method

Zone Food Blocks allow you to personalize the Zone Diet for your body by calculating how many grams of protein, carbohydrates and fat you are allowed to eat per day.

The number of Zone blocks you should eat per day depends on your weight, height and waist size. You can find an online calculator here:

https://zonediet.com/resources/body-fat-calculator/

The average man eats 14 Zone Blocks per day and the average woman eats 11 Zone Blocks per day.

A main meal such as breakfast, lunch and dinner comprises three to five Zone Blocks, while a snack only ever comprises one block.

Each Zone Block consists of a protein block, a fat block and a carbohydrate block.

Protein block: Contains 7 grams of protein.
Carbohydrate block: Contains 9 grams of carbohydrates.
Fat block: Contains 1.5 grams of fat.

What foods can you eat on the Zone Diet?

A lot of the Zone Diet's favorite foods are similar to those of the Mediterranean diet, which is one of the healthiest diets around. In fact, the creator of the Zone Diet recently published a book called "The Mediterranean Zone" in which he describes the similarities and benefits of the two diets.

Protein

Protein options in the Zone Diet should be low in fat. Good options include:

Lean beef, pork, lamb, veal and venison
Skinless chicken and turkey breast
Fish and shellfish
Vegetarian protein, tofu and soy products
Egg white
Low-fat cheese
Low-fat milk and yogurt

Fat

The Zone Diet encourages choosing a type of monounsaturated fat. Good options include:

Avocados
Nuts such as macadamias, peanuts, cashews, almonds and pistachios
peanut butter
Tahini (sesame paste)
Oils such as rapeseed oil, sesame oil, peanut oil and olive oil

Carbohydrates

The Zone Diet encourages its followers to choose vegetables with a low glycemic index and some fruit. Good options include:

Fruits such as berries, apples, oranges, plums and more
Vegetables such as cucumbers, peppers, spinach, tomatoes and mushrooms, squash, chickpeas and more
Grains such as oats and barley

What you can't eat on the Zone Diet

Nothing is strictly forbidden on the Zone Diet. However, certain foods are considered undesirable as they promote inflammation.

High sugar fruit: such as bananas, grapes, raisins, dried fruit and mangoes.
High sugar or starchy vegetables: Such as peas, corn, carrots and potatoes.
Refined and processed carbohydrates: Bread, rolls, pasta, and other white flour products
Other processed foods: Including breakfast cereals and muffins.
Foods with added sugar: Such as sweets, cakes and cookies.
Soft drinks: Neither sugar-sweetened nor sugar-free drinks are recommended.
Coffee and tea: These should be kept to a minimum as water is the drink of choice.

A sample nutrition plan with food blocks

Here is a sample 14-block meal plan for an average man Breakfast (4 food blocks): Scrambled eggs with turkey ham, vegetables and fruit

2 eggs as scrambled eggs
3 strips of turkey ham
30 grams of low-fat cheese
1 apple
3 1/2 cups (630 grams) cooked spinach
1 cup (156 grams) cooked mushrooms
1/4 cup (53 grams) cooked onions
1 1/3 teaspoon (6.6 ml) olive oil

Lunch (4 food blocks): Grilled chicken and egg salad with fruit

90 grams grilled skinless chicken
1 hard-boiled egg
Up to 2 heads of iceberg lettuce
1 cup (70 grams) raw mushrooms
1 cup (104 grams) cucumber slices
1 sliced red bell bell pepper
2 tablespoons avocado
1/2 teaspoon walnuts
1 teaspoon (5 ml) vinegar dressing
2 plums

Afternoon snack (1 food block): boiled egg, nuts and fruit

1 hard-boiled egg
3 almonds
1/2 apple

Dinner (4 food blocks): Grilled salmon, lettuce and sweet potato

170 grams grilled salmon
1 cup (200 grams) baked sweet potatoes
Up to one head of lettuce
1/4 cup (37 grams) raw tomato
1 cup (104 grams) cucumber slices
2 tablespoons avocado
2/3 teaspoon (3.3 ml) olive oil

Evening snack (1 food block): Cottage cheese, nuts and fruit

1/4 cup (56 grams) cottage cheese
6 peanuts
1/2 orange

How does the Zone Diet work?

The Zone Diet claims to optimize your hormones to allow your body to enter a state known as "the zone". This is the state in which your body is optimized to control inflammation through your diet.

The purported benefits of the Zone Diet include:

A quickest possible loss of excess body fat
Maintaining wellness at an older age
Slowing down the rate of ageing
Improved physical and mental performance

Dr. Sears recommends having blood tests done every 3 months to determine if you are in "the zone".

The TG/HDL ratio

This is the ratio of bad fats, known as triglycerides, to good HDL cholesterol in your blood. A lower value means you have more good cholesterol, which is healthier.

The Zone Diet recommends a value below 1 as a good value, which is low. A high value for your TG/HDL ratio increases the risk of heart disease (1).

The TG/HDL ratio can only be determined by a doctor.

The AA/EPA ratio

This is the ratio of omega-6 to omega-3 fatty acids in the body. A lower value means that you have more omega-3 fatty acids in your blood, which has an anti-inflammatory effect.

The Zone Diet recommends values between 1.5 and 3, which is low. A high AA/EPA ratio is associated with a higher risk of depression, obesity and other chronic diseases (2, 3).

You can determine this ratio at home with a test kit available on the Zone Diet website.

HbA1c, also known as glycated hemoglobin

This is a marker for your average blood sugar over the last three months. A lower value means that you have less sugar in your blood.

The Zone Diet recommends a value below 5%, which is low. A higher HbA1c value is associated with a higher risk of diabetes (4).

The HbA1c value can only be determined by a doctor.

Supplements recommendations

The Zone Diet recommends the use of omega-3 supplements such as fish oil to maximize the health benefits. Omega-3 fatty acids lower levels of bad LDL cholesterol and may also reduce the risk of other chronic diseases (5).

The Zone Diet also recommends the use of polyphenol supplements, which contain molecules found in plants with antioxidant properties.

The scientific evidence on polyphenols is mixed. Although they have benefits such as reducing the risk of heart disease, they can also have risks such as reducing iron absorption (6, 7).

Benefits of the Zone Diet

Following the Zone Diet can have many benefits.

Unlike other diets, the Zone Diet does not have strict prohibitions on certain foods. However, it does recommend avoiding options such as added sugars and processed foods that are considered unfavorable. This can make the Zone Diet more appealing to people who find it difficult to cope with food restrictions.

The foods recommended in the Zone Diet are very similar to the foods in the Mediterranean Diet. The Mediterranean diet has been shown in numerous studies to be one of the best diets for long-term health (8, 9).

The Zone diet also allows for some flexibility as there are two ways to follow the diet. The Zone food block method can also help with fat loss as it controls the amount of calories consumed daily. It is well known that controlling calorie intake can help with weight loss.

Disadvantages of the Zone Diet

In addition to the benefits mentioned, the Zone Diet also has some disadvantages.

The Zone Diet makes some claims about health benefits based on the theory behind this way of eating. However, there is little scientific evidence that this theory can produce the claimed results (10).

For example, the Zone diet claims to improve performance. However, a study conducted on athletes following the Zone Diet found that the athletes lost weight as well as endurance and became exhausted faster than other athletes (11).

Another claim regarding the Zone Diet is that it reduces inflammation. The Zone Diet claims that your body is in the optimal "zone" once your blood levels reach target levels.

However, although some research shows that the Zone Diet may improve blood levels, more research is needed before we can say whether it significantly reduces inflammation in the body (12).

There is also little scientific evidence to support the 40% carbohydrate, 30% protein and 30% fat ratio as the optimal ratio for fat loss and health benefits.

Another study compared the effects of a 40% carbohydrate, 30% protein and 30% fat diet with the effects of a 60% carbohydrate, 15% protein and 25% fat diet. This study concluded that the subjects who followed a diet similar to the Zone diet lost more weight (13). However, this difference could also be related to the higher protein intake (14).

Interestingly, this study found no significant differences in blood glucose, fat and cholesterol levels between the two groups.

This does not fit with the claims made about the benefits of the Zone Diet and could mean that the improvements in blood lipid levels seen in other studies may have more to do with omega-3 fatty acid and polyphenol supplementation and less to do with the Zone Diet itself.

Should you try the Zone Diet?

At the end of the day, you should choose the diet that best suits your lifestyle.

The Zone Diet might be ideal for you if you're looking for a diet that includes similar food options to the Mediterranean Diet, but gives you clearer guidelines to follow. However, the purported health benefits of the Zone Diet should be viewed with skepticism. Although the theory behind this diet could be linked to better health, there is not enough scientific evidence to say that the Zone Diet will reduce your risk of chronic disease, slow down the aging process or improve physical and mental performance.

If you want to adopt healthy eating habits, the Zone Diet could help you get started and help you control your portions.

In the end, however, what matters in the long run is that your diet is based on whole and unprocessed foods - regardless of the name of the diet you choose.

References:

Source: https://www.healthline.com/nutrition/zone-diet

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