Ever since the time of ancient hunter-gatherers, fasting has been around in human society for quite some time. Back then, supermarkets and refrigerators were not available, meaning that food was not as readily accessible and could not be stored in large quantities. This resulted in humans evolving in a way where they are able to function without food for long periods of time, and it is actually more natural for humans to fast from time to time rather than eating 3 or 4 meals per day. Fasting is also part of certain religious or spiritual practices such as Buddhism, Christianity, Islam and Judaism. Periods of fasting accompanied by periods of eating is a currently popular eating pattern referred to as intermittent fasting. Since time is divided into periods of fasting and eating, intermittent fasting is thought of to be more of an eating pattern rather than a diet. This article will briefly cover 6 popular types of intermittent fasting and the effects of this eating pattern. 

One type of intermittent fasting is the 16/8 method, also known as the Leangains protocol. Breakfast is skipped and the daily eating period is restricted to 8 hours. For example, food can be consumed from 12 pm to 8 pm, leaving 16 hours as the fasting period. Another type is the 5:2 diet, in which 500-600 calories are consumed on 2 non-consecutive days of the week. On the other 5 days of the week, there are no limitations or restrictions on food consumption at all. The third popular type of intermittent fasting is eat-stop-eat, in which 24-hour fasting occurs once or twice a week. It is common to start this 24-hour fasting by skipping dinner one day and fasting until dinner time of the next day. During the fasting period, water, coffee, and other zero-calorie drinks are allowed.

Another type of intermittent dieting is alternate-day fasting, in which every other day is a 24-hour fast or consumption of only a few hundred calories (e.g 500). Since a 24-hour fast every other day can be difficult for beginners, it is recommended that they start off with choosing to consume a few hundred calories on the alternate days. On the other hand, the warrior diet allows for food every day, but consumption depends on the time. During the day, small amounts of raw fruits and vegetables are consumed until the evening is reached, in which there are 4 hours available for a large meal. Lastly, there is spontaneous meal skipping, in which 3 meals are consumed a day, but any one of the three can be skipped depending on your mood, hunger, etc. There is no scheduled date of when the meal should be skipped or which meal should be skipped. For example, if you wake up not feeling hungry, it is fine to skip breakfast and just have lunch and dinner that day. 

What these types of intermittent fasting all have in common is that they restrict calorie consumption, and would theoretically lead to weight loss as long as one does not consume excess calories or overeat during the non-fasting periods. If intermittent fasting is tried, diet quality is as important as diet quantity. Consuming high-calorie foods and junk food during the non-fasting periods does not balance out the fasting that is performed. The general consensus is that the 16/8 method is the simplest, most sustainable, popular, and easier methods to follow. 

It is worth noting that despite the various types of intermittent fasting, they may not work for everyone, and they are not recommended for individuals who have or are prone to eating disorders. There may be other health conditions one may have that may not be compatible with intermittent fasting as well. In such cases, it may be better to reach out to a healthcare professional and seek professional advice on changes regarding one’s diet to make sure that it does not adversely affect other aspects of one’s health. 

References:

https://www.healthline.com/nutrition/intermittent-fasting-guide

https://www.healthline.com/nutrition/6-ways-to-do-intermittent-fasting#section2