In Tim Ferriss’ new book Tools of Titans he puts forward a method to optimize the process of fasting. In his typical 80/20 approach his formula aims to get the most benefits, in the least amount of time.
His recommended fast is conducted in a 3 day period, spanning Thursday evening to Sunday evening.
You stop eating Thursday night. Friday morning you go for a long walk to push you deeper into ketosis. Friday and Saturday you consume a moderate amount of exogenous ketones and MCT oil (as you see fit), to give you a boost while you’re keto adapting. And Sunday evening you break the fast.
Here’s the process in more detail if you don’t have Tools of Titans to hand:
- Eat a low carbohydrate dinner around 6pm. Make that the last meal of the day. Go to bed as normal.
- Drink some caffeine if needed, then get out the door and walk within 30 minutes of waking.
- Bring at least 1 litre of water, with some added salt (to prevent headaches/cramping), and sip as you walk.
- Walk for 3-4 hours(!). Filling up/buying more water as needed.
- Arrange phone calls for this time, to make the time productive.
- The idea behind the walk is that you use up your glycogen stores, forcing your body to move quicker into deep ketosis. The quicker you get into ketosis, the less time you spend feeling sub-optimal, and the less potential muscle wastage.
Friday Day (post walk)
- Consume exogenous ketones or MCT oil 2-3 times throughout the day.
- Tim primarily uses KetoCaNa and C8 (Caprylic Acid). Other sources Tim has mentioned are Quest Nutrition MCT Powder and high quality MCT Oil.
- This provides 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.
- Upon waking, test blood ketones. You are aiming to be at 0.7mmol or greater. Make sure to use a ketone blood testing kit like the Precision Xtra because urine testing strips (the cheaper option) are not accurate enough.
- If you’re at 0.7mmol, great, proceed normally with your day.
- If you’re under, consider going for another extended walk, and then re-test.
Saturday & Sunday Day
- Add further exogenous ketones, MCT oil or fat if you need a boost. Once you are deep into ketosis they can be omitted.
- Incorporate some salts in your water throughout the day. This can either be in the form of table salts, or via a specially formulated solution such as SaltStick electrolyte replacement pills.
- Break your fast. Tim suggests for longer fasts, some care is needed on the re-feed. But for this 3 day fast, it doesn’t matter as much. Eat what you find to eat.
Tim Ferriss now aims to do this 3 day fast process once per month. With a 5-7 day fast once every 3 months.
If you’d like to talk more about fasting, or share your experience doing this one, join this open Facebook group on the subject.
If you enjoy Tim Ferriss’ work, you may also enjoy this post on Rhonda Patrick’s recommended supplements.