Skip to Content

Tim Ferriss Fasting Technique – 3 Day Protocol

Tim Ferriss Fasting Technique – 3 Day Protocol

Some of the links in this post are affiliate links. This means if you click on the link and purchase the item, we will receive an affiliate commission from the vendor at no extra cost to you. These business relationships allow us to keep bringing you great EatMoveHack content. All opinions remain our own.

Tim Ferriss is a “superhuman” of sorts when it comes to entrepreneurship and, well… life. In fact, he is one of the top gurus in the “lifestyle design” space due to his famous book, The 4-Hour Workweek. In it, he shares his process for creating a business that only requires 4 hours of work per week.

One could say that he knows a thing or two when it comes to work-life balance. So it’s no surprise that he has the advice to share about health as well as business.

In one of his books, Tools of Titans, he reveals his own tools for staying healthy and in shape. The foundation of his routine involves something called intermittent fasting

In this guide, we’ll walk you through Tim Ferriss’ fasting routine so that you can acquire some of those superhuman benefits for your own life.

Who is Tim Ferriss?

Tim Ferriss is a serial entrepreneur and author of the highly regarded book, The 4-Hour Workweek (as well as several other award-winning books). He also runs a podcast, The Tim Ferriss Show, and is an angel investor.

His first business was BrainQUICKEN, which he ran for 9 years and then sold to a private equity firm. He is also a public speaker and continues to share his advice for living a healthy, successful life.


  • Born July 20, 1977, in East Hampton, New York
  • Received his BA from Princeton University in 2000
  • Started his career in Sales while growing his own internet business (BrainQUICKEN)


  • Awarded as one of Fast Company’s “Most Innovative Business People” 
  • Recognized as one of Fortune Magazine’s “40 under 40” 
  • Runs a podcast, The Tim Ferriss Show
  • Author of five #1 New York Times and Wall Street Journal bestsellers (The 4-Hour Workweek, Tools of Titans, Icons, and World-Class Performers) The 4-Hour Chef & The 4-Hour Body
  • He is an investor/angel advisor for multiple companies, including StumbleUpon, Evernote, and Shopify
  • Was the first American to hold a Guinness World Record in tango

Tim Ferriss’ book – Tools of Titans

In Tim Ferriss’ latest book, Tools of Titans: The Tactics, Routines, and Habits of Billionaires, Icons, and World-Class Performers, he shares his own tools for “optimizing” his lifestyle. 

Beyond practical business advice and tools, he also talks about his diet and health routine. One of his tools for hacking his health is his intermittent fasting protocol.

He further goes into his preferred method for optimizing the process of fasting. In his typical “80/20 Principle” style, he aims to get the most benefits in the least amount of time.

Tim Ferriss’ Intermittent Fasting & Caloric Restriction Technique – Overview

Tim Ferriss’ fasting program is conducted over a 3-day period and consists of long periods of intermittent fasting. It’s an aggressive protocol, especially if you’ve never fasted before.

What is intermittent fasting?

According to the health information site Healthline, intermittent fasting is one of the most popular health trends today.

It involves a cycle of eating and fasting (not eating) for certain periods of time throughout the day (or over several days). 

There are many different fasting methods. Some people only fast in the morning by skipping breakfast. Some people skip lunch. Some people fast for the entire day.

However, most of these methods don’t include information on what to eat or what not to eat; they just pertain to when you eat.

Tim Ferriss has his own intermittent fasting protocol that includes a 3-day eating/fasting cycle. He adheres to this protocol due to its countless potential health benefits.

What are the benefits of intermittent fasting?

Tim Ferriss lists some of the many benefits associated with intermittent fasting. These potential benefits include:

  • Increased autophagy (cleaning out of damaged cells) — which amongst other things, plays a vital role in inducing pre-cancerous cell death
  • Immune system regeneration
  • Reduced inflammation
  • Increase in neurogenesis (production of new brain cells)

Other benefits commonly cited are weight loss, lower risk of Type 2 diabetes, a decrease in inflammation, and cancer prevention.

Tim Ferriss’ “Slow Carb” Diet

Tim Ferriss also asserts that people who follow this regimen and sticks to a “slow-carb” diet, can lose up to 20 pounds in 30 days (without any exercise).

Compared to the traditional low carb diet, his slow carb diet supports the idea that carb consumption is okay, as long as they are the right kind of carbs.

People still need sufficient calories in order to have energy throughout the day, and slow carbs (as opposed to quickly-digested carb foods) are more sustainable, according to Ferriss’ theory. 

Check out our post on Tim’s Slow-Carb Diet.

Tim Ferriss’ 3-Day Intermittent Fasting Protocol

In Tools of Titans, Ferriss breaks down his 3-day fasting protocol, which starts in the evening (of the day prior to the first day) and ends in the evening of the third day. 

His regimen involves intermittent periods of fasting, and of consuming certain supplements and water. Again, this is an aggressive protocol and may be difficult for those who have never fasted before.

His entire 3-Day process is outlined in his book, Tools for Titans, but the below information is pulled from his podcast transcripts and this health blog as a supporting resource.

Pre: Evening

The evening prior to starting the 3-day fast, Tim Ferriss recommends consuming a slow carbohydrate dinner (around 6 PM). That is the last meal of the day before bedtime. Then, the next morning, the real routine begins.

Day 1: 12 Hours 

On the first day of the fast, he has broken into two periods: Morning and Daytime. He covers the exact protocol he follows on the first day.

Image of whole roasted coffee beans Tim Ferriss' recommendation


  • Drink caffeine to start off the day (Ferriss recommends black coffee or tea with coconut oil)
  • Go for a 3-4 hour walk within 30 minutes of waking up; bring a bottle of water with you with some added salt (prevents cramping)

The long walk serves the purpose of using up your glycogen stores. This forces the body further into ketosis.

The faster you reach ketosis, the less time you feel the negative effects of hunger. Walking also helps reduce muscle wastage.


  • Consume exogenous ketones or MCT oil 2-3 times throughout the day

What ketones should you use? Ferriss primarily uses KetoCaNa & KetoForce as exogenous ketone sources. Both these products contain 11.7g of Beta-hydroxybutyrate per serving.

Dom D’Agostino, a leading authority on ketosis, and one of Ferriss’ regular podcast guests, also use another product called Keygenix PRIME. It comes in powder form and contains Beta-hydroxybutyrate mixed with MCT powder. The mix of ketone salts and MCTs provide both a quick burst of energy and a longer-lasting ketone release.

MCT oil covers a range of MCT fractions; C8, C10 & C12. To induce maximum ketone production from MCT oil, you want pure C8 oil (also known as caprylic acid).

This can be found in Bulletproof Brain Octane. Keep an eye out for MCT oils that have low levels of C8, and are mostly C10 and C12. Whilst they are technically MCT oils, they won’t raise ketones as well.

The intention of these ketone sources is to provide your body and brain energy until your ketone levels elevate naturally. At which point, the feelings of hunger will reduce and you will feel like you have more energy.

Day 2: 24 Hours

Day 2 consists of more fasting along with the consumption of more ketones and MCT. 


  • Upon waking, test blood ketones. You can do this using a home ketone meter. You want to be at 0.7mmol or greater.
    • If you’re at 0.7mmol, you’re good to go.
    • If you’re below 0.7mmol, go for another extended walk and then take the test again.


  • If you need a boost during the day, feel free to consume exogenous ketones or MCT oil. Once you reach ketosis, these can be omitted.
  • Ferriss also recommends adding sodium to your water throughout the day. Himalayan sea salt or even SaltStick electrolyte pills work great for this.

Day 3: 36 Hours

Day 3 is the final stretch of Tim Ferriss’ intermittent fasting protocol. If your stomach is growling at this point, just know that there is only 1 day left of fasting and then you can return to a regular (healthy) diet.


  • Day 3 follows the same protocol as Day 2. Add exogenous ketones or MCT oil as needed until you reach ketosis. Add sodium to your water to sustain you throughout the day.


  • On the final evening of Day 3, you can break your fast! Again, Ferriss recommends following a slow-carb diet rather than hopping right into the junk food.

For longer fasts, Ferriss says some care is needed on the “re-feed”. But for this 3-day fast, you can eat whatever you find to eat that qualifies as healthy and, preferably, slow-carb.


Tim Ferriss Supplement Recommendations

Ferriss references several different types of supplements throughout his fasting regimen. These are vital to keeping your energy up throughout the day, even as you are battling hunger. On the list include BCAAs, creatine, and protein powder.


For your BCAA ( Branch-Chain Amino Acid) Ferriss recommends Dom D’Agostino’s favorite BCAA product, Xtend. It’s keto-friendly, sugar-free, and contains 0 calories.


Ferriss’s favorite creatine powder is Kre-Alkalyn Efx. It includes a “Ph-correct” formula with a ph of 12.

Protein Powder

Ascent is a sponsor of Tim Ferriss and is his favorite brand of whey protein powder for post-workout recovery. On Ascent’s website, Ferris is quoted as saying, “If you want cleaner, purer, less processed protein that you can trust — which I certainly do — then Ascent protein is the option for you.”

Read: Tim Ferriss Supplements – What He Takes and Why

Tips for Following Tim Ferriss’ 3-Day Fasting Regimen

Tim Ferriss’ fasting protocol is scheduled for one 3-day fast, once per month. He also recommends a 5-7 day fast once every 3 months. 

Here are some additional tips for how to make the most of his intermittent fasting routine:

Tip #1: “That which gets measured gets managed”

In one of his podcast episodes, Tim Ferriss states that those following his protocol should get regular DEXA (body composition) scans to track their body fat and muscle mass. This will give you information on how your body is responding to fasting and being in ketosis.

Tip #2: Do weight training

Ferriss recommends doing weight training as an exercise in order to increase muscle mass and maximize the benefits of ketosis.

Tip #3: Ease into the “slow-carb” diet first

The intensity of the 3-day fasting routine is not lost on him. It’s not for everyone. So before jumping head-first into the fasting protocol, he recommends trying out the slow carb diet methods first.

That way, you have less of a risk of losing control and eating unhealthy foods when you are not fasting. It may also help curb your cravings during fasting.

Final Thoughts

Tim Ferriss’s 3-day fast is a very strict regimen, even for the most seasoned of fasters. 

If you’re just dipping your feet into intermittent fasting, it’s recommended that you try fasting for shorter periods of time in order to see how your body responds.

Switching from a Standard American Diet to hardly eating at all for 3 days is a big leap, and it may take time for your body to adjust.

Before you start on this, make sure to get all the information about the diets, supplements, and biohacks you plan on trying so you stay safe and get your ideal body.

This page was originally published in May 2018 but has been updated to reflect new information.

If you enjoyed learning about Tim Ferriss’ fasting in greater detail, you may also enjoy:


David Pedersen

Thursday 11th of April 2019

Hi Tim,

Been doing the Keto eating for about 3 weeks, decided to do a 3 day fast for the first time. Wondered if drinking coffee with one tablespoon MCT Oil + one tablespoon Butter, once a day is not breaking my fast??

Appreciate the article.

An American

Thursday 31st of August 2017

Some proponents of fasting such as Martin Berkham assert that as long as you stay under 50 calories, you are still in the fasted state.

From the evolutionary point of view it would make sense. If you were wandering across a desert for days, without much to eat, you would still find the occasional bug (full of fat) or worm to put in your mouth. Since it would not give you nearly enough calories, you would stay in the fasted state.

A teaspoon of butter contains 33 calories. Put one into your coffee and drink it slowly, taking an hr or so. This allows you for two cups, and you are still in the fasted state.

I did this during my last 5 day fast: 1 coffee in the morning. My ketones were off the chart and reached 6mmol/L with blood sugar level in the 68 mg/L range or so.

Hope this helps


Wednesday 10th of May 2017


Afraid I'm not Tim; this is just his method.

But to answer your question...

Technically yes, consuming any form of calories breaks a fast. By the strictest definition.

However, assuming the aim isn't the vanity of "I did a 3 day water fast", and instead you're optimizing towards a health goal, then it matters less.

With the method above, TIm is aiming to transition as quickly as possible into ketosis. And he includes exogenous ketones as part of the "on ramp" into ketosis to reduce the sub-optimal feeling whilst one isn't eating, and wants their ketone production to ramp up.

The coffee + MCT + butter combo doesn't contain any carbohydrates, so won't slow down your transition into keto.

(one thing to mention is that any milk you add does contain small amounts of carbohyrdate in the form of a sugar called lactose)

So I'd say go for it. Once you hit keto, you'll get the therapeutic benefits associated with it.


Friday 2nd of November 2018

One thing I have noticed with an extended fast is that it not only helps me physically reset but it helps me to mentally stay on track and not go askew.


Friday 31st of August 2018

Great article, have done several medium to long fasts and always wondered why I didn't get into deep ketosis..... now I have an idea ! Thanks for posting.

Geoff Robinson

Friday 27th of July 2018

Starting the Ferris style three day fast later today - in the poscast/book tools for titans he mentions putting lemon juice in the water. Is that needed and does it have any effects pr venting ketosis / autophagy?


Tuesday 10th of April 2018

Hi, I started this fast almost exactly 24 hrs ago. I did everything to the T yesterday - had a cup of coffee, took a brisk 4 hour walk within 30 minutes of waking, drank water with himalayan salt throughout my walk, drank a couple bottles of water with Kegenix Prime and had two table spoons of Bulletproof brain Octane Oil in herbal tea post walk/before bed. My ketones levels are now at a mere 3.4. Why?! I generally eat a very healthy slow carb diet and I'm only 15 lbs over my goal weight. Can you help me make sense of this? In the mean time, I will go on another long walk hoping to achieve ketosis (5mmol+). Thanks!