If you have any doubts or concerns you should consult a medical expert before startinga fasting regime
12 hour fast
In this fasting you need to adhere to a 12-hour window every day.
This type of intermittent fasting plan may be a good option for beginners. This is because the fasting window is relatively small, most of the fasting occurs during sleep, and the person can consume the same number of calories each day.
The easiest way to do the 12-hour fast is to include the period that you are asleep in the fasting window.
16:8
The 16:8 is probably the most popular form of intermittent fasting that you can incorporate into your day to day life. To keep it simple, you basically have an eight hour window which you can eat about 2–3 meals, and then fast for 16 hours.
For example, you stop eating after dinner at 6pm, and do not have your breakfast until 10am the following day, you can then eat for 8 hours in that window, and the cycle begins again.
You can change the timing according to your schedule—so for example you may prefer to eat earlier or later in the day giving you some flexibility for your dinner time as well.
This type of fasting can be achieved relatively easily and is recommended for most people as a starting point
20:4
The 20:4 is very similar to the 16:8 and its is a type of time restrictive eating based on a 20 hour fast, with only a four hour eating window.
Generally, you can eat as much as you want during the four hour time window when you can eat. the theory is that you only have 4 hours to eat in so its supposed to be impssible to eat too many calories.
Depending on what you eat this is obviosly not 100% true and you should still eat good, nutritious food and not processed food, foods loaded with sugar. That would defeat the purpose.
The four hour eating window usually happens in the evening, but can be any part of the day that suits you. One of the most common eating windows is eating two meals between 2pm and 6pm, and fast for the remaining 20 hours.
This would be suitable for those who are extremely confident with intermittent fasting.
5:2
The 5:2 or fast diet encourages fasting for 2 days of the week.
For any two days, calories are restricted to only 500–600 for women and men, respectively.
Calories can be spread out across multiple meals throughout the day, or eaten all in one. For the remaining five days, eating is not restricted by fasting.
For this to work you should pick 2 of the easiest days in a week that you can do this type of fast and do not pick back to back days.
24 Hour fast
The idea is to fast for 24 hours between each meal.
For example, eat at 6pm on day one and fast till 6pm the next day.
Alternatively you can choose to eat breakfast or lunch, and fast for 24 hours till the next day.
The idea is that you eat a meal each day, but allow your body to fast for extended periods.
This type of fasting is usually done once or twice per week, but can be adopted more frequently.
36 hour fast
This is an extended version of the 24 hour fast.
So for example you can have dinner on day one, fast for the entirety of day two, and then have breakfast on day three.
This type of fast can help jump start your transition into ketosis, or push you into a deeper state of ketosis.
This can be done as little or as often as once a week, month or year. Not recommended doing it to often and its very difficult for beginners
Alternate day fasting
As the name implies, this involves fasting every other day.
On fasting days, your calorie intake is restricted to one meal of 500 calories, or complete fasting (without any calories).
On the Alternate days, you can eat normally. Long-term, this is an intense method of fasting, and is extremely difficult to sustain.
Variations
There are a couple of variations especially on the 16:8
14:10 – Can’t quite make it to the 16 hours, then try a 14 hours fast and 10 hour eating window. You can gradually work your way to 16:8
18:6 – If you get comfortable with the 16:8 you can extend the fasting period of time for another 2 hours. This can potentially enhance any benefits