Review of the 16/8 interval fasting system based on research

Periodic (interval) fasting is a diet that involves alternating periods of eating and starvation. Such a meal regimen has a lot Proven beneficial properties .

One of the most popular and studied is protocol 16/8. But it also has contraindications and side effects that should be taken into account.

What is the 16/8 protocol?

Interval fasting 16/8 is a nutrition scheme according to which a person completely refuses food and high–calorie drinks for 16 hours a day. In the remaining 8 hours, you can eat any food.

Following this protocol is much easier than it might seem. Most often, it's enough to skip breakfast and not eat at night. For example, you can take any amount of food from 12:00 to 20:00. And from 20:00 to 12:00 the next day to starve. But you can also choose any other time intervals.

Such a meal schedule can be repeated in any sequence: from 1-2 times a week to every day. There are no restrictions on the duration of this diet.

It is important to understand that Protocol 16/8 is a diet, but not a diet. It does not set limits on the qualitative composition of food and the caloric content of the diet, but only indicates the time interval when it is possible to eat. This makes it a very popular way to control body weight, as well as promote overall health.

However, if you want to use  interval fasting for weight loss , additional rules must be followed. For faster weight loss, it is advisable to monitor the total daily caloric content of the diet (the energy value should not exceed the normative indicators).

Among the main positive properties of the 16/8 scheme, the following can be distinguished: Improving brain function , normalization of blood glucose and cholesterol levels, prevention of malignant and cardiovascular diseases.

6 useful properties

Protocol 16/8 is considered the most studied option for short-term fasting. Its proven beneficial properties are discussed below:

1. Weight loss. This type of fasting increases the activity of metabolic processes in the body, increases the breakdown of adipose tissue cells. The described properties (especially when rationing the caloric content of the daily diet) allow not only to maintain weight, but also to reduce it if necessary. The effect is scientifically proven. For example, foreign specialists installed that interval fasting accelerates metabolism by 3.6%. Experiments by Australian scientists demonstrated that such food restriction is especially useful for obese people: body weight loss in just 4 months can reach 9-16%.
2. Normalization of glucose levels.  Proven that short–term fasting reduces the concentration of sugar in the blood by 3-6%, insulin - by 31%. Such metabolic effects can prevent the early development of type II diabetes mellitus.
3. Lowering blood pressure. According to the data scientists from the USA, such a regime helps to reduce systolic and diastolic blood pressure by 6% in 2 months.
4. Prevention of atherosclerosis. Periodic fasting, according to research data , reduces the content of total cholesterol, as well as atherogenic fractions (TAG – by 32%, LDL – by 25%) in the blood. As a result, the development of pathologies such as coronary heart disease, myocardial infarction, chronic cerebral ischemia, etc. is prevented.
5. Prevention of malignant diseases. Cyclic fasting, according to research , helps to increase the life expectancy of rats suffering from oncological pathologies. French specialists proved that it enhances the effect of chemotherapy drugs.
6. Increase in life expectancy. Human studies and evidence base are limited. Animal experiments show positive results. Experiments on mice have demonstrated an increase in life expectancy of up to 75%.

An important advantage of intermittent fasting 16/8 is its effectiveness for weight loss, but at the same time  absence loss of muscle mass, which can be "boasted" by a small number of modern diets.

How to observe correctly?

First of all, you need to choose the optimal time for eating – 8 hours during the day. The time interval can be any, the most popular is from 12:00 to 20:00.

At the time selection stage, it is allowed to conduct experiments and choose the optimal period to which the body will respond most positively.

During the fasting period it is allowed to drink ordinary water in unlimited quantities. It is also acceptable to drink tea or coffee without sugar, milk and other high-calorie additives.

During the meal period you need to eat evenly throughout the entire interval in order to stabilize the level of glucose and various hormonally active substances in the blood, as well as satisfy hunger.

It is recommended to consume high-quality (natural) products. The following groups are perfect:

1. Fruits: apples, bananas, oranges, peaches, pears.
2. Berries: any.
3. Vegetables: broccoli, cucumbers, tomatoes, leafy greens, cauliflower.
4. Grain crops: rice, barley, buckwheat, oats.
5. Fats: coconut oil, olive oil, avocado.
6. Protein products: chicken, turkey, beef, eggs, nuts, flax seeds, etc. It is better to give up eating pork.

The use of sweet and high-calorie drinks (Coca-Cola, "energy", etc.) is unacceptable.

An important role is given to the energy value of the daily diet. Systematic overeating can negate all the benefits of interval fasting 16/8. This is especially critical if you decide to starve for weight loss.

The calorie content of the daily diet can be calculated using the following formulas:

For men: BMR = 88.36 + (13.4 x weight, kg) + (4.8 x height, cm) – (5.7 x age, years).

For women: BMR = 447.6 + (9.2 x weight, kg) + (3.1 x height, cm) – (4.3 x age, years).

Example: Female, 45 years old. Body weight &8212; 80 kg. Height &8212; 175 cm. BMR = 447.6 + (9.2 x 80) + (3.1 x 172) – (4.3 x 45) = 447,6 + 736 + 533,2 – 193,5 = 1523,3 calories.

Sample menu for the week

Below is a sample menu with specific food items for the week. Remember that in order to comply with the 16-hour fasting period, you will have to give up at least one meal. Most people prefer to do without breakfast or without dinner.

Safety, side effects

Short–term fasting 16/8 is an extremely convenient and easy-to-perform way to correct a health condition. However, any method has its drawbacks.

According to the latest scientific research, interval fasting is less beneficial for women than for men. Women should choose more "gentle" options and adhere to the technique several days a week or every other day.

Scientists from the USA claim that 3 weeks of a strict interval starvation regime (24 hours of fasting every other day) negatively affects the sensitivity of peripheral tissues to insulin.

Prolonged fasting also affects hormonal balance.

Women should not follow this regime during pregnancy. According to the data According to Polish experts, limiting the intake of nutrients leads to a decrease in the production of gonadotropin-releasing factor responsible for the secretion of hormones necessary for the proper functioning of the female reproductive system and normal fetal development.

The absence of these biological substances is also fraught the development of infertility, osteoporosis and other adverse effects. Experiments on rats revealed a decrease in ovarian volume (when fasting for more than 3 months).

The 16/8 partial starvation protocol is also contraindicated in the following conditions:

1. Low body weight (BMI less than 18.5).
2. Tuberculosis.
3. Type I diabetes mellitus.
4. Hyperthyroidism.
5. Tachysystolic forms of arrhythmias and AV blockages of the II and III degrees.
6. Condition after myocardial infarction (within a month from the moment of vascular catastrophe).
7. Chronic heart failure (IIb-III degree).
8. Liver diseases (chronic viral hepatitis, cirrhosis).
9. Chronic renal or liver failure.
10. Hypertension or symptomatic arterial hypertension.
11. Diseases of the digestive system. The group includes: peptic ulcer of the stomach and duodenum, gallstone disease.
12. Age over 75 or less than 14 years old.
13. Pregnancy and breastfeeding.

Following a diet is characterized by the appearance of the following side effects:

• Headaches;
• Constipation;
• Vertigo;
• Weakness;
• Drowsiness;
• Photopsies (flies, sticks in front of the eyes).

Dieting against the background of contraindications is unacceptable, the development of side effects indicates serious abnormalities in the body that have developed during the restriction of food intake.

Answers to frequently asked questions

This section discusses the most controversial situations and issues regarding the 16/8 mode:

1. Is Protocol 16/8 suitable for women? As already mentioned, the female body is more sensitive to limiting the intake of nutrients. It is recommended to change the standard scheme (for example, to fast for 12-14 hours instead of 16 hours). You should also adhere to the method not on a regular basis, but periodically: several times a week (for example, Monday, Wednesday, Friday) or every other day.
2. How long can you eat according to such a system and how often? If the diet is well tolerated by the body, there are no restrictions on the duration of fasting. With the development of adverse reactions, you should enlist the support of a doctor.
3. Is it possible to follow a pregnancy regimen? Such fasting negatively affects the state of a woman's reproductive system, which can lead to an unfavorable pregnancy outcome. In addition, the health of the fetus is negatively affected by the unsystematic intake of nutrients into the mother's body, which are extremely necessary for adequate growth and development. Conclusion: during pregnancy, the technique is prohibited.

Conclusion

1. Thus, cyclic fasting 16/8 is a special meal regime in which you can eat only 8 hours a day, and the remaining 16 hours are given to hunger.
2. The technique allows you to reduce weight, and also provides reliable prevention of diseases from the endocrine, cardiovascular, and digestive systems. It prevents the appearance of oncological pathologies and increases the overall life expectancy.
3. During fasting, it is advisable to normalize the daily energy value of the diet and give preference to natural foods.
4. If there are contraindications or side effects, it is necessary to consult a doctor to avoid the negative effects of diet on the body.