Intermittent fasting: who is it suitable for, how and why to join

Talking about fasting, nowadays, for many people may seem crazy and is a subject that, in fact, generates controversy. However, an eating method called “intermittent fasting” has become increasingly popular, especially among celebrities such as Deborah Secco, and among people who already follow a healthy lifestyle. And you, have you heard of it?

The proposal, although controversial, is not as crazy as it may seem at first glance, that’s because intermittent fasting, in fact, is not recommended for everyone, requires professional monitoring, and, above all, is based on serious studies.

Nutritionist Pâmela Miguel explains that intermittent fasting is a type of food program that alternates programmed periods of absence of food with periods of controlled food intake. “Currently, this type of ‘diet’ has become popular, as studies have shown health benefits when fasting is performed in a guided manner”, she highlights.

Maybe you’re wondering: but is intermittent fasting a good option for me?

Calm! It is worth emphasizing that intermittent fasting is not a recommended program for everyone; It is generally indicated for people who have been following a balanced diet for a long time and, especially, a diet with low carbohydrate intake (low carb).

In this context, below you will find out everything about this method and clarify your main doubts!

How does intermittent fasting work?

Pamela explains that fasting consists of not eating macronutrients (carbohydrates, proteins and fats) for a certain period (8h/12h/16h/24h).

“The concept of fasting comes from the period of our ancestors where there was no food available at all times. The body adapted to live with these periods without food and the fat reserves were used as a source of energy”, highlights Pâmela.

Also according to the nutritionist, fasting has as one of its goals to balance the levels of the hormone insulin, thus improving hunger control and helping to prevent chronic diseases. “Within the fasting period, consumption of water, lemon water, teas and coffees without sugar or sweetener is allowed,” she says.

Nutritionist Gabryella Batista, from Aliança Instituto de Oncologia, explains that the body, after going without food for a certain time, uses more energy substrates of its own than those from the diet. “So, the body starts, for example, using the fat stored in the adipose tissue instead of the fat ingested from the diet”, she says.

Regarding hormones, Gabryella reinforces that insulin levels in the blood drop significantly (which facilitates fat burning), as well as blood levels of the growth hormone hGH can increase by up to five times (which favors the increase in mass). muscle).

Types of Intermittent Fasting

There are different protocols for performing intermittent fasting. And the best option for each case, of course, can only be indicated by the nutritionist. But, here are the main examples:

Method 16/8

Pamela explains that the 16/8 method consists of eating within a period of 8 hours and remaining for a period of 16 hours without eating, being able to consume only water, water with lemon, teas and coffees without sugar or sweetener.

Example of 16/8 fasting, according to nutritionist Pâmela:

• Monday – Wake up (7:00 am) / Have breakfast (8:00 am) = balanced diet / Lunch (12:00 pm) = balanced diet / Afternoon snack (4:00 pm) = balanced diet / Dinner (until 7:00 pm) = balanced diet.
• Then, no food from 19:00 on Monday until 11:00 on Tuesday.

This type of fast, according to Pamela, can be done once, twice or even three times a week.

5:2 method

Pamela explains that the 5:2 method consists of determining 2 days a week to consume ¼ of the total calories consumed during the other days of normal eating. The caloric intake in these 2 days is around 500 to 600 calories.

Eat-To-Eat Method

Gabryella explains that this protocol involves fasting for 24 hours, once or twice a week. “That means dinner will be held, for example, at 7 pm, and then the next meal will be dinner at 7 pm the next day,” she says.

Pamela reinforces that this method provides for 24-hour fasting, alternating with days of balanced diet. Check out an example cited by the nutritionist:

• Monday: Breakfast (7am) ​​= normal diet / Fasting throughout the day, with only water, lemon water, teas and coffees without sugar or sweetener.
• Next meal only at breakfast on Tuesday (7am).
• During Tuesday, a normal eating routine follows.
• On Wednesday, follow the same routine as on Monday.

It is worth noting that these are the most well-known protocols, but, as Pâmela explains, there are fasts for periods of 8 hours without food, fasts for periods of 12 hours without food and even protocols of 36 hours without food. “All respecting the concept of consuming only water, water with lemon, teas and coffees without sugar or sweetener during fasting periods and a balanced diet when returning from the feeding period”, he adds.

Gabriella also comments that a well-known protocol is 12-hour daily intermittent fasting. “The person has the last meal of the previous day, sleeps for approximately 8 hours and then goes another 4 hours without eating in the morning”, she exemplifies.

8 benefits of intermittent fasting

But why intermittent fasting? Is there really an advantage to this style of eating? Yea!

According to Pâmela, well-programmed and guided intermittent fasting can lead to several physiological adaptations of the body, generating different benefits, such as:

1. Decreased levels of LDL cholesterol (“bad cholesterol”) and triglycerides;
2. Lowering blood pressure;
3. Better control of insulin levels and improved insulin resistance, contributing to greater control of hunger and prevention of chronic diseases;
4. Decreased levels of cortisol (“stress hormone”);
5. Reduction of body fat;
6. Increased levels of growth hormone;
7. Improved concentration;
8. Anxiety reduction.

Gabryella highlights that the epidemic of metabolic abnormalities (obesity, metabolic syndrome, type 2 diabetes mellitus) has caused an increase in the prevalence of cardiovascular diseases.

“Under these conditions, affected individuals show important improvements when they change their eating habits. And, in this context, recent studies have elucidated the modulation of metabolism by intermittent fasting. Animal tests showed lower blood glucose and insulin levels, a reduction in the volume of visceral fat, in addition to greater resistance to stress”, he explains.

Intermittent fasting contraindications

Gabriella highlights that the main contraindications are:

• Children
• Seniors
• pregnant women
• Patients with renal failure
• diabetics
• Patients with infections or a deficient immune system
• anemic patients
• Patients using controlled medications

Pâmela points out that intermittent fasting cannot be adhered to by everyone! “Fasting should always be guided by a professional nutritionist or nutritionist, as not everyone will benefit from the practice of fasting.”, he says.

More questions about intermittent fasting resolved

The subject is somewhat controversial, so it is common for many doubts to arise. Below, you explain the main ones:

1. What are the main changes that occur in the body when fasting?

Pamela explains that fasting promotes hormonal and metabolic changes in the human body, which can improve the functioning of metabolism. “Fasting also promotes the activation of genetic factors involved in the body fat burning process, thus promoting weight and body fat reduction,” she says.

“Fasting also improves the control of insulin levels and improves insulin resistance, contributing to greater control of hunger and the prevention of chronic diseases”, adds Pâmela.

2. Can there be negative consequences to fasting?

Gabryella comments that long periods of fasting can alter the balance of hunger/satiety hormone production, which can promote long-term disturbance. “We should also investigate claims regarding aging and biomarkers of longevity. Studies have shown hyperphagia (overfeeding) to occur at times when food was available,” she says.

Thus, once again, the need to adhere to intermittent fasting is reinforced only when there is an indication and monitoring by a nutritionist or nutritionist.

3. Can I drink fluids while fasting?

Pâmela highlights that, during fasting, it is allowed to consume only water, lemon water, teas and coffees without sugar or sweetener.

4. Can I exercise normally while fasting?

“I do not recommend exercising during the fasting period. It is advisable to keep exercising on days when intermittent fasting is not being practiced”, highlights Pâmela.

Gabryella reinforces that drops in glucose levels can interfere with the evolution of training or even make it impossible to practice in longer periods of fasting.

5. Is intermittent fasting safe?

Intermittent fasting is only safe and brings health benefits when done under the guidance of a nutritionist or doctor, highlights Pâmela.

“Before starting intermittent fasting, the professional will ask for tests to analyze the patient’s metabolic conditions and the safety in applying this food practice”, adds nutritionist Pâmela.

6. Can fasting decrease muscle mass?

When done wrong, unscheduled and unsupervised by a nutritionist or doctor, yes. “The period of intermittent fasting should be well programmed, as well as the feeding period of the days without the practice of fasting. An unbalanced diet after fasting will not bring the benefits of fasting”, emphasizes Pâmela.

Gabryella comments that weight loss in general can cause loss of muscle mass and, therefore, it is important to continue practicing sports and maintain adequate protein consumption, as well as other nutrients. “There are studies showing that intermittent fasting causes less muscle loss than an aggressive calorie restriction diet,” she says.

7. Can I continue my supplementation while fasting?

Supplements should be analyzed by the professional who is guiding the fasting, highlights Pâmela. “Supplements that contain carbohydrates, proteins and fats should be excluded. Some antioxidant supplements help to potentiate the fat-burning process stimulated by fasting,” she says.

Gabryella reinforces that supplements cannot be caloric enough to take the body out of the fasting state. “Vitamin and mineral supplements can be used, but maltodextrin-based supplements, whey protein, for example, should not be consumed while fasting,” she says.

8. What are the side effects of fasting?

When well oriented and…