The Zone Diet, is it really balanced?

The Zone Diet, is it really balanced?

Let’s analyze the Zone Diet to see if it is actually healthy

Currently, there are many types of diets for many different purposes. For example, you have probably heard about the artichoke diet, the weight watchers diet, the Mediterranean diet, the ketogenic and Paleo diets, etc.

But all of them have something in common:

To distribute the macronutrients and food that will help us stay healthy

In this article, we will talk about a diet that is becoming quite trendy. Moreover, we will see how useful or harmful it can be four our health.

In the end, each one will be able to come up with their own conclusions. Although we should always consult a specialist (Dietitian or nutritionist).

The origins of the Zone Diet

The zone diet was created by Barry Sears, an American biochemist

According to Barry, the macronutrient balance that we have followed up until now is not correct, which is why it causes several pathologies. That macronutrient balance would be 15-20% of protein, 20-25% of fat and 50-60% of carbohydrates

This researcher from the Medicine School of the University of Boston studied lipids for 30 years.

He is a referent when it comes to controlling the hormone response during a diet. In addition, he has several patents in the United States to treat cardiovascular diseases

Percentages of the Zone Diet

Like we said, he did not accept the distribution and he redefined the macronutrient percentages as:

  • 30% Protein
  • 30% Fat
  • 40% Carbohydrates

Distribution of Carbs, Protein and Dietary Fat

The reasoning behind this new way of distributing the nutrients is actually insulin, among other factors.

Regulating Insulin, the Objective of the Zone Diet

As we already know, a carbohydrate excess in our body increases the amount of insulin released by the pancreas. Consequently, we may compromise this substance that will lose its efficacy with time.

Moreover, let’s not forget that it is a anti-lipolytic hormone. This means that as long as it is present in the blood, it will hinder our ability to use fat as energy.

That is why following a diet that limits the carbohydrate intake will reduce the blood insulin with the following benefits:
  • Insulin will be more efficient when it comes to transporting the nutrients inside the cell
  • The body will be able to use fat as energy
  • It will produce more satiety

Can caffeine improve the insulin sensitivity?

Some studies suggest that taking caffeine could alter the absorption of glucose by the muscle tissue. This happens not because of caffeine, rather, it is due to the high epinephrine levels.

A person holding a cup of coffee

It seems that this substance would be responsible for the deterioration of the insulin sensitivity and the ability to absorb glucose by the muscles

Although, as a counterpoint, physical exercise would be able to reduce the effects of caffeine on the muscle tissue

Meal Distribution in the Zone Diet

This is not only about changing the macronutrient distribution that we mentioned previously. In fact, it would also involve:

Keeping this proportion in all the meals. In other words, each meal will have to be made up of 30% of protein, 30% of fat and 40% of carbohydrates

Moreover, we should eat every 5 hours and the carbohydrates will need to have a low glycemic index. Therefore, you will have to avoid all those products and refined sugar with a high glycemic index.

A man doing exercise at the gym

Like any healthy diet and lifestyle, they suggest doing physical exercise regularly throughout the whole week

Summary of the Zone Diet

This would be the base of the zone diet. As we can see, it is just a diet to meet our daily calorie requirements with:

  • Natural products such as good quality and high biological value protein (rich in essential amino acids).
  • Moreover, healthy fat with a good supply of monounsaturated and polyunsaturated fatty acids.
  • Finally, complex carbohydrates, specially those with a low glycemic index.

Macronutrients of the Zone Diet


The recommended daily dose of protein is between 1.2g/kg of body weight, up to 2.5g/kg of body weight. Obviously, this will depend on several factors such as sports that demand a higher supply of this macronutrient

The zone diet does not establish a fixed amount of protein per kg of body weight. Instead, this amount will equal a percentage of our daily calories. As we have seen before, this diet establishes a 30% of the daily calories.

The reasoning behind these amounts is nothing else than taking advantage of the effects of protein:

  • Satiating effect.
  • Enhanced thermogenesis.
  • Less blood glucose.
Therefore, the protein needs to be of a good quality in order to avoid saturating the kidneys. You can take them from lean meat, white and fatty fish, vegetable protein like tofu, etc.


The fat supply also increases when compared to the values of a traditional diet. A 30% against a 20-25%

This number us based on the utilization of omega 3 monounsaturated fatty acids. These elements will support our cardiovascular health, with the following properties: preventing the onset of diseases on the arteries and nervous system, lowering the LDL cholesterol (bad) and triglycerides and increasing the HDL (good). Moreover, it has a anti-inflammatory and anti-cancer effect, it lowers the blood pressure, etc.

We can obtain fat from unrefined oils such as coconut, linseed, olive; food like avocado, olives, nuts like almonds, walnuts, pistachios, etc.


Surprisingly, carbohydrates are more limited than usual in this diet

We will only take a 40% of the daily calorie requirements. As we mentioned previously, they need to be low glycemic index carbohydrates in order to avoid triggering insulin resistance.

Oats in a heart-shaped bowl

Oats is a cereal with a very low GI, which is ideal for this type of diet.

Moreover, we can also use fruit and vegetables, since they have a low calorie content as well as a low glycemic index.

Macronutrient distribution per calories

Now that we have seen what this diet is all about, I will give you my point of view:

Protein Distribution

When it comes to the protein, I think that the percentage is a little bit high. However, with a good diet and plenty of water, this should not be an issue

But this amount of protein would be extremely high in hypercaloric diets. For example, a person that weighs 80kg and follows a diet of around 4000 kcal/day:

  • Calories from protein: 4000 kcal x 0.30 = 1200 kcal from protein (total calories)

If we divide this result between 4kcal from 1g of protein:

  • 1200 kcal / 4 kcal/g protein = 300g protein/day

As we can see, a person that weighs 80kg would have to eat 300g of protein a day. This supply is considerably higher to 2.5 g/kg of body weight.

If this person would follow the 2.5g/kg of weight:

  • 2.5 g/protein x 80 kg of body weight = 200g protein/day
As we can see, the athlete would be eating 100g of protein that would not affect the muscle mass

Carbohydrate Distribution

When it comes to carbohydrates, the 40% is more moderate that the current recommended intake. In fact, we could even say that it is even low in some cases. Nevertheless, we will be able to control the insulin levels.

When our insulin does not work properly, our health can be compromised.

A man stretching in the sunset

Carbohydrates are the main source of energy used by our body. They are the first deposits used by our cells in order to produce energy.

For instance, high performance athletes rely more on carbohydrates. This is due to the fact that they need energy immediately. Therefore, lowering our intake to just a 40% could be somehow low.

We need to adjust the carbohydrates according to our physical activity

Fat Distribution

Finally, the amount of fat would be a little bit high when compared to traditional diets

This is not necessarily a bad thing. In fact, it can be even beneficial for our health. Providing a moderate-high fat supply will improve our cardiovascular health, as well as helping us lose weight, lowering the cholesterol, keeping the insulin levels stable, etc.

Salmon, walnuts, avocado, seed and oil on a table

Healthy fat

All of this as long as we take healthy fat, with a good supply of monounsaturated and polyunsaturated

Conclusions about the Zone Diet

To sum up a little bit, the distribution proposed by the zone diet could be quite good. However, it is a double-edged sword and we need to be careful with that.

Therefore, my advice is to not follow excessively strict guidelines. Instead, here you have some common adaptations for everyone:

  • Adjust the amount of protein per gram, making a different between athletes and the general public. Most will not reach that 30% from the zone diet.
  • Identify the type, amount and intensity of our daily physical activity and adjust the carbohydrates supply. If we do very intense activities, several workouts a day, etc. you should eat more carbs.
  • The amount of fat, regardless of the percentage, will have a good quality. Consequently, we will make sure that the lipid profile is correct.

After all, let’s not forget that this is just my opinion about this diet.

I am sure that some people will not agree with me and other will. That is why I encourage you to come up with your own conclusions. Above all, I hope that this article was useful.


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About Javier Colomer
Javier Colomer
"Knowledge Makes Stronger", Javier Colomer's motto, sets out his clearest statement of intentions expressing his knowledge and fitness experience.
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