F, 23
I’m 5’4” and weigh 145 pounds. I have a good amount of excess fat. If I had little fat, I would not fast. But since I have excess fat storage that will be metabolized into fuel for my body, how long can I fast before ending up in the hospital?
I would like to go one week. Is that safe? I know it’s not healthy, but is it still safe in regards to my organ health?
a 7 day fast should be healthy as long as you’re taking in electrolytes like salt and potassium. however, i would be careful about having an unhealthy mindset about fasting. it has so many benefits and is not something to use to punish your body :)
Hi -
One week is safe for nearly everyone who is not suffering from some severe illnesses or near starvation already.
The key to doing it in the least disruptive way is to maintain your sodium, potassium, and magnesium electrolytes daily, and probably in higher quantities than you would expect and/or normally consume if you have been eating the standard modern diet based on carbohydrates.
For example, I am much leaner than you, 43M 178cm and 72kg, pretty fit. I just completed a 10 day fast without any problems at all, and felt amazing. That said, I am a very experienced faster, have pretty advanced metabolic knowledge and experience, and have stayed in a ketogenic metabolic state for most of the last 4 years.
The more adapted your body is to using using fats for fuel, and the more metabolically flexible your body has become from training, staying in ketosis most of the time, and sometimes switching between metabolic states, the easier and less disruptive fasting will be. In my case, I am quite metabolically flexible, and can just stop eating pretty effortlessly.
If you are not metabolically flexible, which is the condition of the vast majority of people, fasting will be very difficult for the first few times, and the first 16-72 hours each time. Your body and brain are probably deeply addicted to carbohydrates, and not able to easily switch into other metabolic states like gluconeogenesis (protein and fat converted to glucose for energy), exogenous ketosis (using fat from your diet as energy), and endogenous ketosis (using fat from your body as energy). As a result of staying in a glycolytic state (carbs based energy) for a lifetime, this adaptation back to our default evolutionary state of metabolic flexibility can take a lot of time, effort, determination, discipline and so on to achieve. The good news is that fasting is by far the most efficient way to gain metabolic flexibility, and the most efficient way to start to become more fat adapted.
A good beginner strategy would be like this:
• Days 1-2 stop eating carbs, and restrict your eating window. I’m talking bacon and eggs, not so-called “keto” products
• Supplement 2-3g sodium bicarbonate, 2g potassium citrate (these amounts may be low), and 500mg magnesium citrate
• From there, start fasting
• Work your way up to the prolonged fast: start with OMAD
• Stay as keto as possible for a week, then do a 48.
• Stay as keto as possible, then do a 72
• When you can easily do another 72, try a 5 day fast
• At day 5, if you feel fine and slept well, go another day
• Do the same on day six
• Prioritize sleep - what disrupts your sleep now will be even more disruptive while fasting
• Stay active, but don’t overtrain - a good brisk walk is a great way to enhance switching into and getting deeper into ketosis, whether it’s nutritional ketosis or fasted ketosis
• DYOR and learn the best practices possible - I would look at Siim Land and Dr Fung as two of the best, highest quality, science-based youtubers on fasting best practices
120 HOURS OF FASTING - My 5 Day Fast Guide Step By Step
Keep us posted, and good luck!
I don’t get the supplements idea.I mean, I’ve done 20 days without any supplement at all other than spring water. Am I doing it wrong?I want to do a 30-40 days fast, so I need to know the optimal way.