Zone Diet: what it is, how it works, example of menu, benefits and criticisms

Zone Diet: what it is, how it works, example of menu, benefits and criticisms

The Zone diet, or Zone diet, is a high-protein and low-carb food program which is based on respecting a precise proportion between the carbohydrates, proteins and fats consumed. A diet that promises to promote weight loss, prevent disease and increase mental efficiency, but which is also highly criticized for the imbalance between nutrients and the health risks it can entail.

What is it about? How does it work? What are its benefits and what are the dangers and contraindications? Find out everything about the Zone diet in our in-depth analysis.

Zone diet: what it is

The Zone diet is a low-carb and high-protein diet that revolves around the 40-30-30 rule: that is, it is based on a precise balance between macronutrients, which provides that, both during main meals and snacks, 40% of calories come from carbohydrates, 30% from proteins and 30% from fats. This proportion is aimed at maintaining a precise hormonal balance and at modulating blood sugar to promote health, weight control and the reduction of inflammation levels in the body.


The Zone diet was devised by the American biochemist Barry Sears, a scholar of lipids, who through research on eicosanoids, hormones that supervise many body functions, discovered that their correct balance can be decisive for well-being and health. This led him to develop a nutritional strategy capable of modulating its production.

But why “zone”? This term, for sportsmen, identifies that state of physical and mental fitness in which it is possible to improve performance. A condition that is difficult to achieve, but which when you reach it, in jargon “you are in the area”, represents the ideal state for the organism.

The first people on whom Sears tested its food method were great athletes: the Zone diet aims to extend the benefits of the “zone” for sportsmen and women to all those who pay attention to well-being and physical fitness.

Starting from the Sears studies, reinterpretations of the Zone diet have been elaborated. This is how the Italian Zone was born, which follows the 40/30/30 criteria of the original American one, but also introduces typically Mediterranean foods into its nutritional tables.

An example is the Mediterranean-style zone diet developed by Dr. Gabriele Buracchi. Further evolutions are the vegetarian and vegan Zone diet.

The Zone diet for hormonal balance

The Zone Diet assumes that the body is a complex metabolic device that responds actively to the food it ingests. In particular, our food choices allow us to modulate hormones that play a crucial role in well-being and weight.

Among them, insulin, glucagon and eicosanoids. The Zone diet, through a precise distribution of nutrients, aims to keep the levels of these hormones within optimal physiological values. This produces as a consequence the reduction of inflammation in the body, the prevention of chronic diseases such as diabetes and heart disease, weight control.

Insulin and glucagon

Insulin and glucagon are two endocrine hormones that mainly perform the function of controlling the fluctuating levels of macronutrients, including sugars, in the blood.

Insulin, also called storage hormone, is produced by the beta cells of the pancreas and regulates the entry of glucose into the cells, which will use it as the main fuel for the body.

If the glucose concentration is adequate, the cells receive the right amount of fuel, but if the concentration is too high, the liver transforms the excess sugars into fats, which are then accumulated in the adipose tissue.

Glucagon is the antagonist hormone of insulin and performs the opposite function: that is, it helps the release of the energy stored in the cells. Therefore, if the secretion of glucagon increases, the body will be driven to use the energy, accumulated in the form of fat, as fuel for its activities.

The Zone diet, through nutrition, modulates the release of these two hormones, implementing blood sugar control.

The eicosanoids

Eicosanoids are an important category of hormones that regulate many fundamental functions of the body, such as the cardiovascular system, blood coagulation, renal function, immune response, inflammation.

These hormones are divided into two types, “good” and “bad”, depending on whether they perform an anti-inflammatory or pro-inflammatory function.

In more detail, different families of substances (prostaglandins, thromboxanes, leukotrienes) are part of the eicosanoids. Some, especially those derived from arachidonic acid (omega-6), increase allergic reactions, cell proliferation, blood pressure, inflammatory reactions, platelet aggregation, thrombogenesis and vasospasm, produce LDL cholesterol and decrease HDL cholesterol.

Those derived from EPA and DHA (omega-3), have opposite effects, i.e. anti-inflammatory and antiplatelet.

The balance between the two ensures the proper functioning of the organism. As in the case of insulin and glucagon, the Zone diet aims to modulate, through nutrition, the production of “good” eicosanoids and “bad” eicosanoids to maintain and promote a state of health and well-being.

Calories don’t count

The Zone diet therefore emphasizes the body’s hormonal response to foods and various nutrients, in contrast to all theories that assign calories a central place within a strategy aimed at health and weight loss.

According to the principles of the Zone diet, calories, which represent the most used tool to determine how much to eat, to choose foods, to compose recipes and meals, are not the best way to evaluate food.

An example: from a caloric point of view, carbohydrates and proteins are equivalent, because they both provide 4.1 calories per gram. But the hormonal response they induce is the opposite: carbohydrates stimulate insulin production, proteins act on glucagon.

According to the principles of the Zone Diet, not taking this into account can lead to the wrong conclusions about the cause of weight gain. This does not mean that to lose weight you should only eat proteins, but it does mean that calories are not the only parameters to consider in setting up a correct diet.

The Zone Diet: the benefits

Here are the main benefits that the Zone diet allows you to obtain. These positive effects are a consequence of blood sugar control and the reduction or prevention of the inflammatory state of the body.

  • Reduced incidence of chronic pathologies related to metabolic syndrome, such as cardiovascular disease, type 2 diabetes, obesity, Alzheimer’s.
  • Better cognitive performance.
  • Increased energy levels and improved physical performance, because the stabilization of insulin and glucagon levels puts the body in a position to use the fats stored in adipose tissue as a source of energy.
  • Reduction of hunger attacks, a consequence of glycemic peaks after meals.
  • Significant weight loss.

Zone diet: the rules

There are 4 basic principles on which the Zone diet is based:

  • Follow the 40-30-30 rule in the distribution of nutrients: 40% carbohydrates, 30% proteins, 30% fats.
  • Divide your meals over 24 hours: it is important that no more than 4/5 hours elapse between a main meal and a snack and more than 3 hours between a snack and the next meal (excluding the night). It is advisable to have breakfast within half an hour of waking up and a snack half an hour before going to sleep.
  • Supplement the diet with Omega 3.
  • Combine the diet with moderate but regular exercise.

The block system

The cornerstone around which the Zone diet revolves is the block system. The block is the tool that allows you to correctly combine foods, from the point of view of both quality and quantity.

Each person, depending on age, gender, the more or less active life he leads, has a different food requirement, which translates into a greater or lesser number of blockages. The block is therefore the brick which, alone or combined with others, forms the basis of all the meals of the day.

Each complete block is made up of 3 blocks, or mini-blocks, of carbohydrates, proteins and fats.

1 block = 1 miniblock of carbohydrates + 1 miniblock of proteins + 1 miniblock of fats

Both blocks and mini-blocks must respect the 40-30-30 ratio between carbohydrates, proteins and fats.

In detail, each block contains:

  • 1 mini-block of Carbohydrates = 9 g
  • a miniblock of Protein = 7 g
  • 1 mini block of Fats = 3 g

But how do you know which foods to bring to the table to compose a block and in what quantities? The Zone diet makes tables available to those who follow it: just choose a food for each macronutrient and use the quantity indicated in the table, which corresponds to a mini-block.

Here are some examples for each miniblock.

There are also specially created snacks on the market that contain the exact breakdown of the block, supplements and sweeteners under the Zona brand. There is a range of products under the Enerzona brand, which in Europe exclusively identifies the Diet Zone created by Barry Sears, which provides the right combination of nutrients to form a block.

The use of these products simplifies diet management, but also increases costs and is not essential.

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