The 12 Levels of Intermittent Fasting

What is Intermittent Fasting?

Simply put: intermittent fasting (IF) is the abstinence from caloric intake (food and drink) over a time period. IF is nothing new or revolutionary. Don’t be fooled by the marketing. It has been a part of the human experience for a very long time. It is just now that it is becoming ‘known’ - scientifically verified - for its benefits.

Evidence is beginning to show that caloric restriction, that is, the absence of glucose and fats from food over a time period triggers a metabolic response that increases fatty acid oxidation (fat burning) and ketone production (alternative fuel used by brain and body), while at the same time preserving lean muscle mass.

It is not just fat loss where the benefits of IF stop. IF alters certain biochemical processes and signalling pathways in the body. This optimises human physiology by slowing the ageing process and onset of disease.

Hormesis is another benefit of IF. A hormetic response is where a beneficial biological effect results from exposure to a stressor. The hormetic effect is dose-dependent; meaning too little equals no effect and too much equals a bad effect. Exercise is a prime example, whereby you expose your body to a mild stressor - lifting weights - and the body compensates by repairing and building the muscle back stronger. But if you try to lift too much weight you risk serious injury.

IF triggers hormesis by promoting cellular autophagy (cell recycling and damage repair) and by boosting your body’s ability to protect itself from future exposure to more intense stressors.

It is through these foundational physiological processes that all the subsequent and marketed benefits of IF stem from. Depending on what particular benefit you want to enhance will determine, which method/level you will choose. So if you want to give IF a go keep reading and pick a level and give it a try.

The 12 Levels

If you’re new to fasting, I would start at the bottom and work your way up. The bottom level is easy, and with ease, it can be integrated into your lifestyle. However, as you go up the levels, the difficultly to adhere and integrate into your life increases. Especially if it is the first time you have tried fasting or you’re starting from a metabolically impaired position i.e. overweight, unhealthy, and hormones out of whack.

If you have fasted before, which levels have you tried? Which fasting method do you prefer? Do you go between different levels or stick religiously with just one?

If you like to gamify goals, treat each level like a pursing a trophy. Try each method out and let me know how you found it, and I will send you digital Trophy.

There are many other fasting methods which I have not included, such as:

· Types of juice fasting;

· Fasting Mimicking Diets;

· Protein Modified Fasting (PSMF).

This is because I don’t consider these methods ‘proper’ fasting, because you won’t reap the full benefits associated with fasting. They are more a form of caloric restriction than fasting*. Which is fine if you want to lose weight. But why - when you can hit two birds with one stone by properly fasting.

Eat, Stop, Eat

This is an OG IF method. It was popularised by Brad Pilon in his book Eat, Stop, Eat, which is well worth a read. It is a newbie-friendly method of IF, as all it entails is 2 x 24-hour fasts a week.

Classic Example: Fast from Monday dinner to Tuesday Dinner. And then fast from Thursday dinner to Friday dinner.


This is a simple and classic method of IF. I first came across this method on Lean Gains many years ago and it is probably the best IF method. This is because it can be adhered to the easiest long term and fits in with a variety of work and training schedules.

With the 16/8 method, you fast for 16 hours and eat within an 8-hour window.

Classic example: Eat between 12:00 - 20:00 and fast between 20:00 and 12:00.


This is a very similar method to the 16/8 IF method, just with a smaller eating window by 2 hours.

Classic example: Eat between 15:00 - 20:00.

The Warrior Diet

This method was made popular by Ori Hofmekler, in his book The Warrior Diet and is roughly a 24 hour fast. The method allows for up to 500 calories to be consumed during the day in the form of low carb vegetables and fruits. In my opinion, it acts as a nice way to ease into OMAD and the book is a good read if stories of heroics and lore motivate you.

OMAD - One Meal A Day

Very simple method and one I like; especially for fat loss and when I need to focus on a task. You just eat one meal a day, usually dinner. Some might find it difficult if they need to consume 3,000 plus calories in one meal, but when cutting on 2,000 calories per day, it feels good to tough through the day and indulge in one big meal.

Alternative Day Fasting (ADF) or 36/12

Alternative Day Fasting was popularised by James Johnson in his book, The Alternate-Day Diet, and is a very simple IF method to comprehend - one day you eat, the next you don’t - repeat ad infinitum. This method can be made a bit more difficult by extending the fast one more night to make it a 36-hour fast. This method is better for fat loss than for performance.

48hr fast / The Snake Diet

This method was popularised by Cole Robinson, who is a bit of character and if you are easily offended, I would stay away from his videos. However, he has a solid method, with a great community, has a plethora of success stories, and sells a decent salt/electrolyte product. He doesn’t set a clear schedule to the IF method, but it’s basically: fast for 48 hours as often as you deem necessary to achieve your goals and your diet should be deliberate and intentional eating.

72 Hour Fast

This timeframe is also utilised in the Snake Diet - so follow the links and advice above. Personally, I have felt great benefits from a 72-hour fast and think it best for its spiritual and cellular autophagy benefits.

However, I don’t do them often. Roughly once every 2 - 3 months or after a period where I have been unable to maintain an optimal diet due to traveling, work commitments, or too much socialising.

5-day Bone Broth Fast

Technically this is not a fast, as you will be consuming calories by drinking bone broth. This method has many health and digestive benefits. It is a great way to start an elimination diet due to digestive or autoimmune issues. Compared to other fasting methods, a bone broth fast is more hassle, as you have to source bones and cook the broth.

On a side note: If you want to start making bone broth regularly - invest in an electric pressure cooker.

5 Day Fast

I could be wrong, but I think Elliot Hulse popularised 5-day fasting - either way - he has a good little series on 5-day fasting which is worth a watch. Like a 72 hour fast, this fast is more for improving health, mental clarity, and self-discipline. There are weight loss benefits - you will lose weight - but I wouldn’t recommend using 5-day fasts as your primary means of losing weight.

Unlike the prior levels, a 5-day fast can pose some health concerns, so please consult you, doctor, before giving it a go. And I would defiantly recommend the consumption of electrolytes during the fast.

7 Day Dry Fast

Dry fasting is abstaining from the intake of all food and water. It’s extreme but it is effective.

This method has been popularised by Dr. Sergei Ivanovich Filonov in his book, Dry Medical Fasting: Myths and Reality.

Filonov argues, during a dry fast your body significantly up-regulates its detoxification pathways to the level of triggering stem cell proliferation. As paradoxical as it sounds, by starving the body of water more robust cells cannibalise weaker cells through a process of phagocytosis. As the weaker cells are cannibalised, the more robust cells absorb the cell’s metabolic water, which hydrates the cells on a much deeper level than consuming water by itself.

On top of that, one’s immune system benefits from dry fasting, when the body is deprived of exogenous water, it wisely rations what endogenous water it has and uses it for only healthy cells. This means weak cells, bacteria, viruses, and parasites will suffer from a lack of water and begin to die off. It will also give significant rest to the digestive system and people with compromised gut walls will see benefits as microvilli will be able to up-regulate healing - remember the adage ‘health begins in the gut’.

I would not recommend trying this as your first fast and it is only for people who have done many of the prior fasting levels. Dry fasting for this length of time can have adverse effects on health and the effects can impact people very differently depending on one’s overall health. The environment you are in will also have an impact such as the heat. If dry fasting for this length of time is done incorrectly severe dehydration and death are possible.

14 Day Fast

This is some fasting length and is better done as a wet fast than a dry fast. As mentioned with other extended fasts, there are benefits and there are also health risks and fasts this long are best done under medical supervision.

382 day fast

I only know of one person to have done this and he is a bit of a ‘man, myth, legend’ in the fasting world, as he fasted for a total of 382 days. I think this is only possible if you are as this man was - grossly obese. If you do not fit that criterion, I think you would be better served by one of the other IF methods. If weight loss is your goal, but you are like this man - stubborn and disciplined and have access to long-term medical supervision, you would like to make celebrity status completing this mammoth fast.


Some IF methods and the authors of those IF methods often claim that their method is best for fat loss, or sports optimisation, or disease preventions, or anti-ageing. I don’t think anyone can truly make that claim but its part of the marketing and selling of the idea.

If one thinks you can utilise IF for three months, then return to a SAD diet and have boosted your life by five years, one is sorely mistaken. If you are after the short-term benefits of fat loss, mental clarity, and a bit of cellular autophagy you will see the benefits of three months. But for the life-enhancing and disease prevention aspects, long-term adherence will be needed. IF is really down to trial and error. It is about finding which method suits your goals, your lifestyle, your psychology, and physiology the best.