Intermittent fasting is a diet where prolonged fasting periods are carried out, between 16 and 24 hours, during which you can only drink water and non-caloric drinks, such as tea or coffee, without sugar or sweeteners.
Intermittent fasting helps strengthen the immune system, improves mood and mental agility, prevents premature aging, and increases the burning of body fat, promoting weight loss.
This lifestyle is only recommended for healthy people and, therefore, it is recommended that it always be done with the guidance of a doctor or nutritionist, to assess the best type of intermittent fasting, according to each person's objective and tolerance. .
Benefits of Intermittent Fasting
The main benefits of intermittent fasting are:
Regulate cholesterol and triglyceride levels: this is because the diet before and after fasting should be low in sugar and fat, in addition to being rich in fiber, which favors the elimination of excess fat, improving cholesterol and triglyceride levels in the blood;
Increase metabolism: contrary to the belief that fasting can slow down metabolism, this only happens in cases of fasting longer than 48 hours.
However, in controlled intermittent fasting, low calorie intake reduces blood glucose and insulin levels. This forces the body to use the body's fat cells, which provide a lot of energy and increase metabolism; Prevent high blood pressure: intermittent fasting reduces bad fat levels (LDL) and increases good fat levels (HDL), facilitating blood circulation and preventing high blood pressure;
Prevent diabetes: intermittent fasting associated with low sugar consumption in the diet helps balance blood glucose and insulin levels, preventing diabetes;
Help you lose weight: going at least 16 hours without eating reduces levels of the hormone insulin in the blood, as well as stimulating the body to use sugar reserves and fat cells, which directly contributes to weight loss. Understand better how intermittent fasting can help you lose weight;
Prevent flaccidity: intermittent fasting promotes increased levels of the hormone GH (growth hormone) in the blood. Therefore, in addition to this hormone facilitating the burning of fat in the body, it also helps to increase muscle mass, preventing sagging;
Detoxify the body: going without food for at least 16 hours, drinking plenty of water and avoiding fatty and sugar-rich foods reduces sugar and fat levels in the body, which helps to balance the intestinal flora and detoxify the body, avoiding problems health issues such as asthma, arthritis, cancer and fatty liver;
Reduce the risk of heart disease: as it is a tool that prioritizes a diet rich in fiber, vitamins and antioxidants, intermittent fasting prevents the formation of fatty plaques in the blood, helping to reduce the risk of cardiovascular diseases, such as heart attack and stroke and atherosclerosis;
Prevent premature aging: reducing sugar and fat consumption, and prioritizing foods rich in fiber, minerals and vitamins, as occurs during intermittent fasting, helps reduce inflammation, promote hydration and stimulate collagen production, reducing wrinkles and premature aging.
During intermittent fasting it is also possible to feel more alert, have improved memory, have more energy, better mood and a general feeling of well-being.
How to do intermittent fasting
To do intermittent fasting, you need to plan periods of restricted food intake, interspersed with periods in which you can eat without restriction. Look a practical guide to starting intermittent fasting.
If you have never fasted before, it is normally recommended to fast once a week for a maximum period of 16 hours. The fasting period can be increased gradually, that is, you can start by doing 12 hours and, as you adapt, increase the fasting hours.
Before starting the fasting period, it is recommended to have a low-carb meal, as this makes it easier to stay hungry during the fast. In the first 4 hours, the body uses the energy provided by the last meal.
Types of intermittent fasting
There are different types of intermittent fasting. The main ones include:
- 16-hour fast : consists of going 16 hours without eating, and eating 3 to 4 meals in the remaining 8 hours of the day;
- 20-hour fast : is done without eating for 20 hours and eating meals during the remaining 4 hours of the day;
- 24-hour fast : it is done with a whole day of fasting, and can be done 2 or 3 times a week.
There is also a type of intermittent fasting in which the person eats without restrictions for 5 days and chooses 2 days to reduce the diet to around 500 calories per day.
Choosing the type of intermittent fasting should always be done with the guidance of a nutritionist or doctor, and may vary according to each person's goals and tolerance.
What is allowed during fasting?
During the fasting period, water, teas and coffee are allowed, without the addition of sugar or sweeteners.
What to eat after fasting
After the fasting period, it is recommended to eat easily digestible foods with a low glycemic index, avoiding excess fats or sugars, as this ensures the results of intermittent fasting.
After fasting, it is important to have a meal with a low glycemic index to ensure good digestive capacity and well-being, which may include:
- Sweet potato;
- Chicken breast;
- Sardines or canned tuna;
- Bone soup.
After fasting, some fruits that can also be consumed with the meal are apples, strawberries, raspberries and blueberries. Furthermore, the longer you go without eating, the smaller the amount of food should be, especially at the first meal. check out more foods with a low glycemic index that can be consumed after fasting .
Foods not recommended
Fried foods or foods prepared with a lot of fat should be avoided, such as French fries, coxinha, white sauce, ice cream, stuffed biscuits or frozen foods, such as lasagna.
To lose weight with intermittent fasting, it is also important to practice physical activity regularly, such as walking or weight training, and preferably guided by a physical education professional.
When not to do intermittent fasting
Intermittent fasting is not recommended in any disease situation, especially in cases of anemia, diabetes, high blood pressure, low blood pressure or kidney failure.
Furthermore, intermittent fasting is also not recommended for children, pregnant or breastfeeding women and people with a history of anorexia, binge eating or bulimia.
However, even if you are healthy, it is important to consult a doctor or nutritionist before starting intermittent fasting.
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- HARVARD HEALTH PUBLISHING. Intermittent fasting: Surprising update . Available at: <https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156>. Accessed on June 9, 2021
- LONG Dan. Effects of Intermittent Fasting on Health, Aging, and Disease . The new england journal of medicine. 38. 26; 2541-2551, 2019
- LESSAN Nader, ALI Tomader. Energy Metabolism and Intermittent Fasting: The Ramadan Perspective . Nutrients. 11. 1-15, 2019
- CHO Yogin, HONG Namki et al. The Effectiveness of Intermittent Fasting to Reduce Body Mass Index and Glucose Metabolism: A Systematic Review and Meta-Analysis . Journal of Clinical Medicine. 8. 1-11, 2019