Tim Ferriss 3-Day Fast Method [2024 Update]

Tim Ferriss’ ‘4-hour’ self-help philosophy and book series made him world famous. His advice on productivity, lifestyle and health optimization has touched millions. The Tim Ferriss Show became the first business/interview podcast to clock more than 100 million downloads and now exceeds a billion. 

While Tim’s views on productivity launched him to global prominence, his conversations today increasingly revolve around health and wellness. One of his pet topics is intermittent fasting – specifically, the 3-day fast method. We delve into Tim’s explanation of this fasting technique, motivation and any additional tips he shares on how you can make it work for you.

Philosophy

Tim regularly refers to himself as a human guinea pig due to his now long-running habit of testing out different theories on improving health and wellbeing then sharing the results with his audience. He has been on some type of intermittent fasting for a while now. Fasting is of course not a new practice even in its more modern non-religious health-centric form. For years, its most ardent advocates have highlighted the health benefits of fasting as evidenced by multiple studies.

As far back as 2017, Tim explained during an interview with Business Insider that he did a 3-day water fast once a month then a longer 5-10 day fast twice or thrice a year. He confirmed that his objective of fasting is the physical and cognitive benefits which initially involved managing his struggle with Lyme disease. Over time, the end goal of his 3-day fast has become to stimulate ketosis, the state of the body using ketones (produced from stored fat by the liver) instead of blood sugar.

Protocol

Tim breaks down the entire schedule of his 72-hour fast in his book, Tools of Titans. In a nutshell however, it involves the following routine. Day 2 has the most elaborate explanation as it covers the actions that you’d repeat on Days 3 and 4. 

Day 1 (Thursday)

• Thursday Evening – He will typically kick off his 3-day fast on a Thursday night and end it on Sunday night. 
• Low Carb Last Meal – A low carb dinner will usually be his last solid meal before the start of the fast.

Day 2 (Friday)

• Sleep Longer – Sleep can do some of the work for you so the more the better. It also helps you avoid the low mood that sometimes bedevils the transition from regular eating. Tim targets 9-10 hours of sleep. 
• Morning drinks – On waking up, take an unsweetened caffeinated beverage like coffee or tea (if required) as well as MCT oil or exogenous ketones. Take MCT oil or exogenous ketones throughout the day every 3-4 hours (Tim does caprylic acid (C8) and KetoCaNa). Consume as much as 4 tablespoons of fat (i.e. coconut oil in coffee or tea) or exogenous ketones. The ketones help plug the gap that would otherwise be occupied by your everyday standard meals.
• Walking – Do a brisk 3-4 hour walk no more than 30 minutes after waking up. Carry a bottle of cold water with a couple of pinches of salt and a small amount of unsweetened lemon juice. The combination of walking and regular hydration speeds up your body’s transition to ketosis (i.e. the body uses ketones instead of glucose as an energy source). Salt helps prevent cramping and headaches.
• Keep your mind occupied – As you do the walk, Tim recommends that you either take in the nature around you, listen to podcasts or make phone calls.

Day 3 (Saturday)

• Sleep longer.
• Repeat the brisk walking and regular hydration cycle of Day 2.

Day 4 (Sunday)

• Sleep longer.
• Repeat the walking and hydration cycle of Day 2 and Day 3.
• Break the fast in the evening at about the same time as it started. Anything solid should do – what you eat during your regular meals. Healthy whole foods are ideal. 
• If you prefer, you can continue on the ketogenic diet to maintain ketosis.

Conclusion

While adhering to the core principles of the 3-day fast is key to success, there is room for flexibility. Depending on what works for you, you could opt for time-restricted feeding, fasting for just a day per month or week, or combining different fasting methods. Whichever method you choose, Tim emphasizes that getting your doctor’s consent is crucial especially if you have not fasted before.