
September 16, 2019
Dr. Peter Attia – Zero Fasting Live Q+A
Watch the video here
Key Takeaways
- Peter’s fasting routine:
- Time-restricted feeding 4-5 days a week
- A 36-48 hour water-only fast once a month
- A 5-7 day water-only fast once a quarter sandwiched by a week of following a ketogenic diet on each end
- During the water-only fasts, Peter doesn’t consume coffee and tries to strength train every day
- Whether or not coffee breaks the fast depends on why you’re fasting in the first place
- Artificial sweeteners belong in the same bucket
- When breaking a prolonged fast, eat something small/low volume, low in glucose, and preferably higher in monounsaturated fats (as opposed to saturated or polyunsaturated fats)
- Strength training during a fast is very important as it helps to preserve muscle mass
- “Don’t try to trade your health for wealth then buy your health back”
Products & Supplements Mentioned
- During Peter’s water-only fasts, he supplements with:
- Doc Parsley’s Sleep Remedy – Use the code “podcastnotes” at checkout for a 10% discount
- Jarrow’s Phosphatidylserine (typically 300 mg) (which also makes it easier to fall asleep)
- Magnesium – he steers clear of magnesium oxide (as it tends to act as a laxative) and instead prefers something like SlowMag
- L-threonate (it’s a magnesium transporter that allows it to get across the blood-brain-barrier more effectively)
- Peter says it’s helped his sleep, whether he’s fasting or not
- Despite various claims, citrus bergamot probably doesn’t enhance autophagy
- You can measure your ketone levels with a Precision Xtra
- Use these lancets these test strips
Intro
- This is a Q&A with Dr. Peter Attia (@PeterAttiaMD) in partnership with the fasting app, Zero
- Peter is The Peter Attia Drive Podcast – check out the Podcast Notes
- Check out the Podcast Notes from Peter’s first Q&A
- Also, check out the Podcast Notes from the Zero Fasting Q&A with Dr. Rhonda Patrick
Peter’s Fasting Routine
- Time-restricted feeding 4-5 days a week
- A 36-48 hour water-only fast once a month
- A 5-7 day water-only fast once a quarter sandwiched by a week of following a ketogenic diet on each end
Where are we in the cause/effect chain of understanding the relationship between obesity and insulin resistance?
- “I feel less knowledgeable today than I did in 2013… My absolute knowledge has grown, but my relative knowledge has shrunk.”
How has fasting improved Peter’s life?
- Perhaps the biggest benefit of all is psychological
- Having a regular fasting practice makes it 10x easier to avoid eating if he only has access to junk food (i.e. on a long travel day)
Advice for Younger People | Increasing Healthspan and Lifespan
- “Longevity is a compounding sport”
- Remember: Slow and steady wins the race
- The more consistent you can be with the way you sleep, eat, and exercise, the greater the benefit you’ll experience much later on
- “Don’t try to trade your health for wealth then buy your health back”
How do you know if intermittent fasting is effectively addressing insulin resistance?
- The short definition of insulin resistance: the body requires more insulin to get glucose out of circulation into the muscle
- Signs include elevated levels of insulin and/or elevated levels of glucose following the ingestion of glucose
- Average blood glucose and the standard deviation of blood glucose levels are good proxies for glucose disposal capability
- Thus, you’d want to look for an improvement in these two numbers
Does coffee break a fast?
- It depends why you’re fasting in the first place
- If your fasting to lose weight…
- No
- If you’re fasting to improve metabolic parameters often accompanied by weight loss (reductions in glucose/insulin)…
- No
- If you’re fasting to reduce inflammation…
- No
- If you’re fasting for gut rest…
- Yes
- If you’re fasting to increase autophagy (the process by which dysfunctional cells digest themselves)…
- We don’t know the answer because we can’t measure autophagy in humans (yet)
- During Peter’s water-only fasts, he chooses not to consume coffee – “But I don’t know definitively that I should not be consuming coffee. My intuition is the less I’m consuming, the better.”
- If your fasting to lose weight…
- In summary – “I don’t know the answer to this question and I don’t know anyone who does”
What about non-nutritive sweeteners like aspartame, saccharine, and sucralose?
- “I think they probably belong in the same camp as coffee”
Major in the Major, Minor in the Minor
- If you’re already fasting, you’re getting 97% of the benefit
- Don’t worry about the 1-3% difference you’d obtain in your physiology by avoiding coffee/artificial sweeteners during a fast
More on Measuring Autophagy
- As mentioned, it’s not currently measurable in humans
- Ideally, in the future, we’d be able to look at a series of biomarkers and determine the extent to which you’re undergoing autophagy
- We know what happens when we fast, so we’re not too far off:
- Glucose decreases
- Insulin decreases
- Free fatty acids decrease
- Some amino acids drop to 0 (like methionine)
- Some amino acids drop and plateau (like leucine)
- Uric acid increases
- “My suspicion is that there are ~25 different biomarkers out there that would then get layered into an algorithm to give someone an autophagy meter if you will”
- We know what happens when we fast, so we’re not too far off:
Sleep Supplements During a Fast
- Many report trouble sleeping during a prolonged water-only fast
- This isn’t solely due to hunger, but perhaps more so due to higher cortisol levels
- There’s an evolutionary reason for this – our ancestors probably treated periods without access to food as a state of hyper-alarm
- This isn’t solely due to hunger, but perhaps more so due to higher cortisol levels
- During Peter’s water-only fasts, he supplements with:
- Doc Parsley’s Sleep Remedy (which contains a very small dose of melatonin: ~20 micrograms)
- Use the code “podcastnotes” at checkout for a 10% discount
- Jarrow’s Phosphatidylserine (typically 300 mg)
- Doc Parsley’s Sleep Remedy (which contains a very small dose of melatonin: ~20 micrograms)
- Note – be careful with long-term melatonin supplementation (it downregulates your melatonin receptors)
- And as a general rule, only use sleep supplements when you need them (i.e. to fight jet lag)
What else does Peter supplement with during a water-only fast?
- Magnesium
- In general, most people are magnesium deficient
- Magnesium also tends to get depleted during a fast (or with general carbohydrate restriction)
- Peter supplements with magnesium every day, but when fasting does so at a much higher level
- During a fast, he’ll stay clear of magnesium oxide as it tends to act as a laxative and instead prefers something like SlowMag
- L-threonate (it’s a magnesium transporter that allows it to get across the blood-brain-barrier more effectively)
- Peter says it’s helped his sleep, whether he’s fasting or not
What should you eat when breaking a prolonged water-only fast?
- From a physiologic perspective, meals low in glucose will produce less of a glycemic spike (which you want to avoid)
- Eat something small/low volume
- Why? – During a long fast, your stomach contracts
- Eat something nutritious – you’re looking to refeed the cells that survived the fast and you want to provide them with the best nutrients possible
- Eat monounsaturated fats as opposed to saturated fats which, especially if shorter chain, can lead to a very upset stomach
- Also, avoid omega-6, polyunsaturated fats as well which are junky anyway
Should you exercise during a prolonged water-only fast?
- Peter recalls a study:
- Two groups of men were calorically restricted by 50%
- Both groups were “exercised like crazy” (similar to ~2 hours of very intense exercise or ~3 hours of modest exercise)
- Men that received testosterone supplementation gained muscle mass
- The other group failed to lose muscle mass
- Exercise is VERY important during a fast
- On the cardio side, pick and choose your battles
- Repeated bouts of extremely high-intensity exercise (like with a Tabata) are very difficult during a fast as your glycogen levels are depleted
- For this reason, this type of exercise is off the table for Peter during a fast
- A step just below the above in intensity (like the pace a runner or cyclist would use during a race) also becomes difficult during a water-only fast (Peter estimates even well-conditioned athletes are ~50%, if not more, dependent on glycogen during this phase of exercise)
- This is known as the “functional threshold power” state
- Peter doesn’t do much of this type of cardio, fasting or not – he much prefers shorter bouts of ultra-high power output or longer battles with zone 2 cardio (below)
- Below the above, we have zone 2 cardio
- Zone 2 is the highest level of output at which you can carry out a conversation (more accurately, your lactate levels must be < 2 mmol)
- Peter typically does four zone 2 workouts a week
- Zone 2 cardio is completely doable in the fasted state, but Peter much prefers to replace his typical zone 2 workouts with strength training sessions (he tries to lift every day during his fast)
- Repeated bouts of extremely high-intensity exercise (like with a Tabata) are very difficult during a fast as your glycogen levels are depleted
- The takeaways:
- Er on the side of lifting more than doing cardio during a fast
- If you do cardio, adjust your expectations in regards to your capacity to produce glycolytic power
- Also, adjust your expectations when lifting
- Strength typically doesn’t diminish during a fast, but your stamina and recovery time between sets will
- Adjust your expectations in general:
- “When I’m fasting, I’m only in the gym for about an hour as opposed to my normal 90 minutes”
- In a sense, strength train during a fast only for as a physiologic stimulus for mTOR
Peter’s Workout Routine
- Lift – Monday, Wednesday, and Friday
- Zone 2 cardio – Tuesday, Thursday, and Saturday, and Sunday
- Tabata workouts on his Peleton – sprinkled throughout
Fasting for Women
- “I would say, based on my clinical experience, in general, it’s harder for women to fast than men. I don’t know why that is.”
- Perhaps there’s an evolutionary reason – it’s much more difficult for women to ovulate or lactate while fasting
- “For women who are trying to get pregnant, I don’t think fasting, I don’t think ketogenic diets, I don’t think anything that signals energy reduction makes sense”
Hot/Cold Therapy During a Prolonged Fast
- “Few things feel better than a sauna during a water-only fast”
- Why? – During a prolonged fast, people experience hypothyroidism
- Thus metabolism slows and you walk around at a lower body temperature (this is why Peter loves fasting during the summer)
- Why? – During a prolonged fast, people experience hypothyroidism
- Cold therapy tends to increases norepinephrine in the brain which enhances mood
- There’s no reason you can’t take a cold shower or bath during a fast
Are there long-term negative effects on metabolism if you time-restrict your eating daily?
- “I don’t think we know the answer yet”
- As a precaution, Peter only time-restricts his eating 4-5 days a week
- He recommends his patients do the same (and on the days they don’t time-restrict, he advises them to focus more on what they eat)
- Peter spent 6 months in 2014 doing eating only 1 meal per day and didn’t notice any negative consequences
Fasting with Hashimoto’s Disease
- Hashimoto’s is a form of hypothyroidism
- Peter’s advice – 100% speak with your endocrinologist or whoever’s managing your hormone medication before fasting
Does citrus bergamot activate autophagy?
- Some people say it does
- “I have never seen a credible piece of evidence to suggest that it could in any way, shape, or form increase autophagy”
- It does have some efficacy at lowing cholesterol – “Though I’m not a fan at using it at all”
- “I’m not a fan of this supplement in any way, shape, or form”
Are there benefits to fasting even if you don’t enter ketosis?
- Definitely yes
- Ketosis = having a blood ketone level of 0.5 mmol or greater
- If you’re frequently eating carbs, your ketone levels are 0 mmol
- When most people wake up in the morning, their blood ketone levels are ~0.1 – 0.2 mmol
- During a prolonged water-only fast, you’ll enter starvation ketosis with a ketone level of 4-7 mmol
- You can measure your ketone levels with a Precision Xtra
- At the end of the day – “It’s a huge mistake to turn fasting into a ketone contest. The idea that the success or failure of your fast is predicated on how high your ketone levels get is total nonsense.”
Additional Notes
- Peter wears a Dexcom G6 continuous glucose monitor
- Peter much prefers glass-bottled Topo Chico to plastic-bottled Topo Chico
- Peter uses both the Lactate Plus and the Lactate Pro to measure his lactate levels during and after doing zone 2 cardio