AMA #13: 3-day fasting, exogenous ketones, autophagy, and exercise for longevity

**Peter Attia** (0:11)
Hey, everyone, welcome to a sneak peek, Ask Me Anything, or AMA episode of the Drive podcast. I'm your host, Peter Attia. At the end of this short episode, I'll explain how you can access the AMA episodes in full, along with a ton of other membership benefits we've created. Or you can learn more now by going to peterattiamd.com forward slash subscribe. So without further delay, here's today's sneak peek of the Ask Me Anything episode.
Welcome to another edition of Ask Me Anything AMA episode 13 I'm joined again today by my head of research, Bob Kaplan. In this episode, we talk about a bunch of things. It was supposed to be rapid fire, but we on the first question got so far off the rails. And I think it literally took up half the time, but it was basically a question about seven day versus three day water fasts. And then that evolved or devolved, depending on how you think of it, into all things related to fasting, how you cope with them, all the things that you would measure, what's happening physiologically, the use of exogenous ketones, et cetera. We then pivoted off to some other topics, such as favorite resources that I have for staying up to date on information as it relates to medicine, health, longevity. We talked a little bit about exercise and specifically how one might craft an exercise program around longevity.
I hope you enjoy this episode of AMA 13

**Bob Kaplan** (1:43)
Hey, everyone. Welcome to another Ask Me Anything or AMA with Peter Attia. Peter, how you doing?

**Peter Attia** (1:50)
Doing well, Bob. How are you?

**Bob Kaplan** (1:52)
Living the dream. Ready to ask you some questions.

**Peter Attia** (1:54)
I'm nervous, man. You got that look in your eye that says you've got questions to make a fool of me or something.

**Bob Kaplan** (2:01)
Well, we're just gonna do a rapid fire and see which ones stick.

**Peter Attia** (2:04)
Okay, rapid fire, meaning you're gonna be on the stopwatch or?

**Bob Kaplan** (2:07)
Yeah, we could do a two-minute drill if you want, and then we'll just go over if we need to.

**Peter Attia** (2:13)
Defeats the purpose. Okay, go for it.

**Bob Kaplan** (2:15)
All right.
First question. Any early observations from your new three-day-per-month fasting regimen?

**Peter Attia** (2:25)
So I guess for folks who maybe aren't familiar, I'll give a bit of background.
For a great deal of time, I would do a seven-day fast once a quarter.
And around Thanksgiving last year, I decided to try something different, which was more frequent fasts that were shorter. And so being completely arbitrary, I was like, well, if I was fasting seven days every quarter, three days a month is almost the same in terms of total aggregate fast time. By the way, Bob, this is not gonna be a two-minute answer, just FYI.
So I decided, well, what if I could do three days a month? And I think part of the rationale was two-fold. One, the seven-day fasts are quite intrusive, just in life in general. I've done enough of them that I can pretty much sail through them, but it's seven days of not eating, not drinking. And I just thought, well, every time I do one of those, I notice that by about the second day of the fast, my glucose levels really start to normalize, as in low levels of glucose. My ketone levels really start to rise. I started to suspect that maybe around day two and day three is when some really interesting metabolic stuff is going on and basically figured, well, what if we just did a slightly less extreme version where we got some of the benefit that we got from the seven-day fast, but maybe not all of it, but revisited that more quickly. So anyway, that was the rationale for it. So actually, by total coincidence, I'm on day one of this month's fast, and we're recording this on, what is it, March 2nd today. So this is the March fast.

**Bob Kaplan** (4:09)
And when was your last meal?

**Peter Attia** (4:11)
My last meal was Sunday evening.
So I will break the fast Wednesday evening.
So now having done one, two, three, maybe four or five of these shorter fasts, they're definitely easier. And that's saying, even though the longer fasts, you get more and more used to them, you have periods during those longer fasts where you're, at least for me, I'm just sort of dragging, I'm kind of wearing it. I'm just not my normal self. For the three day fast, I seem to skate through them a little bit easier. That's one thing. I think the other thing is my exercise tolerance seems higher because obviously I'm not subjected to the same degree of glycogen depletion. So today, for example, not that today's workout counts because it was basically the first day after having a dinner. So this doesn't really a fasted workout, but I suspect I could do the type of work that I did today, which was two hours and super intense, lots of sled work, lots of dead lifts, lots of compound movements. I could do that easily through a three day. Whereas in the longer fasts, I still try to do those activities each day, but I really have to reduce the volume. And I just find that during the three day fast, nothing really seems to happen. I will say this, Bob, I have not done a lab test on myself at the end of a three day. So that's kind of an important thing I still need to do is do a blood test.