Will intermittent fasting be your magic formula for weight loss?

*It is only for medical professionals to read and refer to.
After I have sorted it out for you, why not take a look? Intermittent fasting is currently one of the most popular diets for weight loss.
It is different from the traditional way of dieting.
Instead, it advocates the control of calories within a certain period of time, so it is easier to adhere to than the traditional way of dieting
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However, there are many types of intermittent fasting.
Are there any differences in their efficacy? Is the weight gain only from calorie restriction? Does fasting time also play a role in the weight loss process? A review published recently in the Annual Review of Nutrition systematically assessed the effects of various intermittent fasting regimens on weight and other aspects
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 The effect of various intermittent fasting regimens on body weight This review selected more than 25 studies, involving three intermittent fasting regimens: 1.
Fasting every other day: people fasted every other day and did not eat at all on fasting days (zero Calorie version) or food that only consumes about 500~600 calories (improved version).
There is no restriction on the types of food and calories on alternate days
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Figure 1.
The modified version of alternate day fasting.
The apple label represents the time to eat during the alternate day fast.
The researchers analyzed 3 zero-calorie versions of alternate day fasting studies and 12 modified version of alternate day fasting studies
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They found that: 1.
The zero-calorie fasting program can reduce body weight by 3% to 8% within 3 to 8 weeks, and the weight loss effect is related to the intervention time; 2.
The modified fasting program can reduce body weight by 4% to 8% The peak of weight loss occurred at 12 weeks, and longer-term (24-week) intervention did not lead to more weight loss; 3.
With similar intervention times, the two intervention programs achieved similar weight loss effects
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The researchers further analyzed the calorie intake of the participants and found that whether it is a zero-calorie version or a modified version of the alternate-day fasting program, the total calorie intake of the participants can be reduced by about 20% to 35%.

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This may explain why the two eating regimens achieve similar weight loss effects
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2.
5:2 diet: A further improvement of the alternate-day fasting regimen.
There are only two fasting days per week, and the diet at other times is not restricted
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 Figure 2 The 5:2 diet, the apple label represents the time to eat.
So far, 5 studies have compared the 5:2 diet and the traditional calorie restriction regimen.
After 8 to 52 weeks of intervention, the two dietary regimens have weight loss effects There is no obvious difference
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One study reported that obese patients lost an average of 4% weight after 8 weeks of intervention
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Four other studies that lasted 24 to 52 weeks found that overweight or obese participants lost 7% of their body weight
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 Overall, the weight loss effect of the 5:2 diet is similar to the above-mentioned alternate-day fasting regimen
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 Researchers also observed that the total calorie intake of the 5:2 diet was reduced by 20% to 35%, which was similar to the reduction in energy intake of the alternate-day fasting regimen
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 3.
Time-limited eating: Eat at a specific time every day, usually 4 to 10 hours, but do not limit calorie intake during eating
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 The researchers selected 10 studies that allowed subjects to eat at will within a limited eating time, and found that a shorter time limit did not bring more weight gains to obese people
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 4-hour limited-time diet: There are 2 studies with a 4-hour eating window.
One study found that the weight of obese participants lost 3% after 8 weeks, while another study found that people with normal weights were intervened for 8 weeks.
There was no significant change in weight afterwards
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 8-hour limited-time diet: There are 5 studies with an 8-hour eating window.
The results found that: after 4 to 12 weeks of intervention, the weight of obese participants lost 2% to 4%; one study found that the limited-time diet did not Can reduce the weight of patients; another study that included non-obese patients even found that the weight of participants did not drop but increased
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 9-hour limited-time diet: There is a 9-hour limited-time diet study, and it was found that the weight of obese participants dropped by 1% after 1 week of intervention
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 10-hour limited-time diet: There are two 10-hour limited-time diet studies, and it was found that the weight of obese participants dropped by 3% after 10 to 16 weeks of intervention
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 Therefore, most researchers tend to believe that the benefit of time-limited eating has nothing to do with time, and is closely related to the reduction of energy intake.
Although dietary calories are not restricted, time-limited eating still reduces energy intake by 10% to 30%
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Research Summary After the series of studies are summarized, we can find that: 1.
The weight loss effect of the alternate day and 5:2 fasting regimen is equivalent to that of the traditional daily calorie restriction diet
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2.
The weight loss effect of intermittent fasting is related to the reduction of energy intake, and has nothing to do with the fasting time
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 These studies have debunked some myths about intermittent fasting, and revealed that the root cause of intermittent fasting to lose weight is reduced calorie intake-you cheat your body to eat less, which is why people lose weight
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 You should pay attention to the implementation of intermittent fasting.
Although these intermittent fasts are relatively simple to implement, they are not suitable for everyone.
These types of people should be avoided: pregnant or breastfeeding women and children under 12 have previous diets Persons with a history of disorders, wasting people (BMI<18.
5 kg/m2), the nature of work shifts day and night.
Those patients who need to take medications with food at the prescribed time are fasting, and some adverse reactions will inevitably occur.
When the following occur When you have symptoms, you should do this: 1.
Side effects such as headache, dizziness and constipation may occur during fasting.
Increasing water intake can help relieve headaches caused by dehydration during this period.
Usually these symptoms are fasted for 1 to 2 weeks.
It will fade away later
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 2.
Moderate to high-intensity endurance or resistance training can be done during fasting, and it is recommended to do it before eating after exercise on fasting days
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 3.
There are no special requirements for food during fasting, but eating fruits, vegetables and whole grains can help increase fiber intake and relieve constipation caused by fasting
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 4.
It is not recommended to drink alcohol on fasting days, and it is recommended to use limited calories to provide nutritious and healthy food
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 References: [1] Varady KA, Cienfuegos S, Ezpeleta M, Gabel K.
Cardiometabolic Benefits of Intermittent Fasting.
Annu Rev Nutr.
2021;41:333-361.
doi:10.
1146/annurev-nutr-052020-041327