Overview

Intermittent fasting has recently become one of the many popular health and fitness trends in the world. It improves metabolic health, causes weight loss, and even extends lifespan. It is also often conducted for religious reasons, including in Christianity, Judaism, Islam, and Buddhism.

What Is Intermittent Fasting?

Intermittent fasting (IF) is an eating pattern which involves various meal timing schedules that cycle between periods of fasting (avoiding certain foods or abstaining from eating) and eating.

Intermittent fasting has already been a practice throughout human evolution, since in the ancient times, people didn’t have supermarkets or food available year-round. And sometimes, they have nothing to eat.

In fact, fasting is even more natural than eating 3–4 (or more) meals every day.

Intermittent Fasting Methods

There are different ways of intermittent fasting in which people can choose from. Although they vary in the length of time people should fast, all of them involve splitting the day or week into fasting and eating periods—it’s either you eat very little or nothing at all.

Each method can be effective—nothing is better than the other—but deciding which method is best depends on the individual. Some people may successfully sustain a particular eating pattern and see better results.

Here are 6 various ways to do intermittent fasting:

1. The 16/8 Method

The 16/8 is the commonly used method of fasting, which involves 14–16 hours of fasting every day and restricting your daily eating to 8–10 hours. This method, popularized by fitness expert Martin Berkhan, is also known as the Leangains protocol.

Most people who are fasting usually find this method to be the simplest, most sustainable, and easiest to stick to. This is also recommended for beginners.

With this method, it’s just like not eating anything after dinner and skipping breakfast the following day. For example, if you’ve eaten your dinner at 8:00 p.m. and don’t eat until noon the following day, you are basically having a 16-hour fast.

For women, they are recommended to only have a 14–15-hour fast as they seem to do better with slightly shorter fasts.

However, this method might be hard for those who get hungry in the morning and are used to eat breakfast. For breakfast skippers, this is going to be easy for them.

Drinking coffee, water, and other zero-calorie beverages during the fast helps reduce the feeling of hunger. Also, it is noteworthy that eating healthy foods during eating periods is very important; otherwise, this method won’t work.

2. The 5:2 Diet (Fast Diet)

The 5:2 diet, popularized by British journalist Michael Mosley, involves restricting your calorie intake to 500–600 for 2 non-consecutive days of the week while eating normally during the remaining 5 days of the week.

During the 2-day fasting, men are recommended to eat 600 calories while women 500. For example, you can eat normally every day of the week except Tuesdays and Fridays, and during those days, you only eat 2 small meals of 300 calories each for men and 250 calories each for women.

Although no studies have tested this method, there are several studies on the benefits of intermittent fasting.

3. Eat-Stop-Eat

The eat-stop-eat method, popularized by fitness expert Brad Pilon, involves fasting for 24 hours once or twice every week. This gained popularity for a few years.

For this method, you fast from dinner to dinner the next day, totaling to a 24-hour fast. Let’s say if you had your dinner at 7:00 p.m. Sunday and didn't eat dinner at 7:00 p.m. the following day, then you have successfully completed the full 24-hour fast. Fasting from breakfast to breakfast or lunch to lunch gives the same end result.

However, eating solid foods during the fast is not permitted, but coffee, water, and other zero-calorie beverages are allowed.

If your purpose in fasting is to lose weight, it is very vital to eat normally during the eating periods as if you had not been fasting at all.

For many people, a 24-hour fast may be very difficult. That’s why it is recommended to start off with a 14–16-hour fast before going to a more advanced fast such as this.

4. Alternate-Day Fasting

In alternate-day fasting (alternating “fast” and “feast” days), you do a full fast every other day.

This method, created based on the research findings of an associate professor of nutrition at the University of Illinois, Chicago, Dr. Krista Varady, has several versions: in some, eating 500 calories during the fasting days is allowed. This version is used for many of the test-tube studies that show the health benefits of intermittent fasting. Other alternate-day fasting plans involve abstaining from eating every other day.

Note that going to bed very hungry several times every week is probably unsustainable in the long term and is not very pleasant. This method is kind of extreme, so this is not recommended for beginners.

5. The Warrior Diet

The warrior diet, popularized by fitness expert Ori Hofmekler, involves eating one huge meal at night and small amounts of vegetables and fruits during the day. Basically fasting all day and having a feast at night in a 4-hour eating period.

This was one of the first popular diets to include an intermittent fasting. The diet’s food choices—mostly unprocessed foods—are quite the same with that of the paleo diet.

6. Spontaneous Meal Skipping

It is not really necessary to follow a structured intermittent fasting plan to experience its health benefits. With this method, you simply skip meals from time to time—either when you are too busy to cook and eat or you don’t feel hungry at all.

It’s not true that people need to eat every few hours. We have a well-equipped body to handle long periods of famine.

So if you’re really not hungry one day, you can do a short fast by skipping breakfast and eating a healthy lunch and dinner. Skipping a meal or two is basically a spontaneous intermittent fast. Just ensure to eat healthy foods.

Intermittent Fasting for Weight Loss

With people seeking to improve their health or lose weight, intermittent fasting has become increasingly popular recently. They believe that this style is more sustainable compared with the traditional diets.

Benefits:

Weight Loss

Eating fewer meals during intermittent fasting leads to an automatic reduction in calorie intake. Thus, it can be deduced that with intermittent fasting comes weight loss.

A review study in 2014 found that fasting can cause 3–8% weight loss in just 3–24 weeks, which is a very significant amount, compared with most weight loss studies.

Intermittent fasting helps you eat fewer and burn more calories. It is indeed an effective way to lose weight and belly fat as it also slightly boosts your metabolism while helping you eat fewer calories.

However, if you compensate by eating a massive amount during eating periods, you’ll not likely lose weight at all.

Longevity

A study in 2014 demonstrated that eating proteins increases IGF-1 (a hormone that helps promote normal bone and tissue growth and development) production.

Intermittent fasting restricts calorie intake which can decrease IGF-1 levels. This could potentially extend a person’s lifespan and lessen the risk of chronic diseases.

Cancer

Fasting to restrict calories decreases IGF-1 levels and may result in slower tumor development.

Based on a review in 2019, cancer patients discovered that fasting reduces some of the chemotherapy side effects and therefore increases its effectiveness. The study authors suggested that cancer cells may be deprived with nutrients by way of fasting, which makes them susceptible to chemotherapy toxins.

Long-term calorie restriction is challenging to sustain; thus, doctors do not recommend it to cancer patients. Intermittent fasting, which involves short-term calorie restriction, may be an option for them.

But they must talk to their doctor or dietitian first before they start a fasting diet. It is also important to note that weight loss can have adverse effects for people receiving treatment.

Insulin Resistance

Intermittent fasting reduces insulin resistance which lowers the blood sugar and fasting insulin levels, protecting you from type 2 diabetes.

Heart Health

Intermittent fasting may reduce all risk factors for heart disease, like blood triglycerides, “bad” LDL cholesterol, blood sugar, insulin resistance, and inflammatory markers.

Risks:

While it is true that intermittent fasting produces favorable results in overweight or obese individuals, it can also have adverse effects to those who are underweight.

Its side effects include low energy, changes in mood, tension, extreme hunger, obsessive thoughts about food, depression, confusion, fatigue, and binge eating behavior.

Additionally, restricting calorie intake may interfere with the female menstrual cycle.

Intermittent fasting is not recommended for people who are underweight and those who have eating disorders, recent surgery, mental health conditions, fever or illness, and other underlying health conditions.

Conclusion

Most people seeking to lose weight prefer to do intermittent fasting instead of the traditional diets. The 6 secret methods to succeed with intermittent fasting are as follows: the 16/8 method, 5:2 diet, eat-stop-eat, alternate-day fasting, warrior diet, and spontaneous meal skipping.

All of them can be effective so long as you stick with whatever plan you choose and you don’t compensate for your fasting by eating a lot during the eating periods. No method is better than the other so long as you are dedicated and strictly adhering to your plan.

If you are just starting with intermittent fasting, the 16/8 method is best for you and then you can go on with a more advanced method once your body has made the necessary adjustments. But if you have an underlying health condition, it would be better to hold off on intermittent fasting as it can be downright harmful.