It’s claimed to cause weight loss, improve metabolic health, and perhaps even extend lifespan.
Not surprisingly given the popularity, several different types or methods of intermittent fasting have been created.
Every method can be effective, but figuring out which one works best depends on the individual.
Here are 6 popular ways to do intermittent fasting.
1. The 16/8 Method: Fast for 16 Hours Each Day
The 16/8 Method involves fasting every day for 14 to16 hours and restricting your daily “eating window” to 8-10 hours.
Within the eating window, you can fit in 2, 3, or more meals.
This method is also known as the Leangains protocol and was popularized by fitness expert Martin Berkhan.
Doing this method of fasting can actually be as simple as not eating anything after dinner and skipping breakfast.
For example, if you finish your last meal at 8 p.m. and don’t eat until noon the next day, you’re technically fasting for 16 hours.
It’s generally recommended that women only fast 14-15 hours, because they seem to do better with slightly shorter fasts.
For people who get hungry in the morning and like to eat breakfast, this method may be hard to get used to at first. However, many breakfast skippers actually instinctively eat this way.
It’s very important to primarily eat healthy foods during your eating window. This method won’t work if you eat lots of junk food or an excessive number of calories.
The 16/8 method involves daily fasts of 16 hours for men and 14-15 hours for women. Each day you’ll restrict your eating to an 8- to 10-hour “eating window” where you can fit in 2, 3, or more meals.
2. The 5:2 Diet: Fast for 2 Days Per Week
This diet is also called The Fast Diet and was popularized by British journalist Michael Mosley.
On the fasting days, it’s recommended that women eat 500 calories and men eat 600 calories.
For example, you might eat normally every day of the week except Mondays and Thursdays. For those two days, you eat two small meals (250 calories per meal for women and 300 calories for men).
As critics correctly point out, there are no studies testing the 5:2 diet itself, but there are plenty of studies on the benefits of intermittent fasting.
The 5:2 diet, or the Fast diet, involves eating 500-600 calories for two days out of the week and eating normally the other 5 days.
3. Eat-Stop-Eat: Do a 24-Hour Fast, Once or Twice a Week
Eat-Stop-Eat involves a 24-hour fast, either once or twice per week.
This method was popularized by fitness expert Brad Pilon and has been quite popular for a few years.
By fasting from dinner one day to dinner the next day, this amounts to a full 24-hour fast.
For example, if you finish dinner at 7 p.m. Monday and don’t eat until dinner at 7 p.m. the next day, you’ve just done a full 24-hour fast.
You can also fast from breakfast to breakfast or lunch to lunch. The end result is the same.
Water, coffee, and other noncaloric beverages are allowed during the fast, but no solid foods are permitted.
If you’re doing this to lose weight, it’s very important that you eat normally during the eating periods. As in, eat the same amount of food as if you hadn’t been fasting at all.
The potential downside of this method is that a full 24-hour fast may be fairly difficult for many people.
However, you don’t need to go all-in right away. Starting with 14-16 hours and then moving upward from there is fine.
I’ve personally done this a few times. I found the first part of the fast very easy, but in the last few hours, I became ravenously hungry.
I needed to apply some serious self-discipline to finish the full 24 hours, and I often found myself giving up and eating dinner a bit earlier.
Eat-Stop-Eat is an intermittent fasting program with one or two 24-hour fasts per week.
4. Alternate-Day Fasting: Fast Every Other Day
Alternate-day fasting means fasting every other day.
There are several different versions of this method. Some of them allow about 500 calories during the fasting days.
Many of the lab studies showing health benefits of intermittent fasting used some version of this method.
A full fast every other day can seem rather extreme, so it’s not recommended for beginners.
With this method, you will be going to bed very hungry several times per week, which is not very pleasant and probably unsustainable in the long term.
Alternate-day fasting means fasting every other day, either by not eating anything or only eating a few hundred calories.
5. The Warrior Diet: Fast During the Day, Eat a Huge Meal at Night
The Warrior Diet was popularized by fitness expert Ori Hofmekler.
Basically, you “fast” all day and “feast” at night within a 4-hour eating window.
The Warrior Diet was one of the first popular “diets” to include a form of intermittent fasting.
This diet also emphasizes food choices that are quite similar to a paleo diet — whole, unprocessed foods that resemble what they looked like in nature.
The Warrior Diet is about eating only small amounts of vegetables and fruits during the day and eating one huge meal at night.
6. Spontaneous Meal Skipping: Skip Meals When Convenient
You don’t actually need to follow a structured intermittent fasting plan to reap some of the benefits.
Another option is to simply skip meals from time to time, such as when you don’t feel hungry or are too busy to cook and eat.
It’s a myth that people need to eat every few hours or they’ll hit “starvation mode” or lose muscle.
The human body is well equipped to handle long periods of famine, let alone missing one or two meals from time to time.
So, if you’re really not hungry one day, skip breakfast and just eat a healthy lunch and dinner. Or, if you’re traveling somewhere and can’t find anything you want to eat, do a short fast.
Skipping one or two meals when you feel inclined to do so is basically a spontaneous intermittent fast.
Just make sure to eat healthy foods during the other meals.
Another more “natural” way to do intermittent fasting is to simply skip one or two meals when you don’t feel hungry or don’t have time to eat.
The Bottom Line
There are a lot of people getting great results with some of these methods.
Intermittent fasting is not for everyone. It’s not something that anyone needs to do. It’s just another tool in the toolbox that can be useful for some people.
Some also believe that it may not be as beneficial for women as men. It may also not be a recommended choice for people who have or are prone to eating disorders.
If you decide to try intermittent fasting, keep in mind that you need to eat healthy as well.
It’s not possible to binge on junk foods during the eating periods and expect to lose weight and improve health.
Calories still count, and food quality is still absolutely crucial.
For more details on intermittent fasting, read: Intermittent Fasting 101 — The Ultimate Beginner’s Guide.
- Intermittent Fasting Could Be Part of a Healthy Lifestyle, Studies Show
- Does Intermittent Fasting Boost Your Metabolism? - EcoWatch