Keto fasting combines a very-low-carb diet with intermittent periods of fasting—and it has the potential to improve your sleep, cell regeneration, and gut health. Find out more about this lifestyle in this episode of RHR.
In this episode, we discuss:
- How Dr. Mercola got started with keto and fasting
- Three benefits of intermittent fasting
- How safe is fasting?
- Fasting from an ancestral health perspective
- The possible downsides of long-term keto and water fasting
- How to start keto fasting
- Tips on making keto fasting work for you
Hey, everybody, it’s Chris Kresser. Welcome to another episode of Revolution Health Radio. Really excited about the interview this week. I’m going to be talking with Dr. Joe Mercola. Dr. Mercola was trained as a board-certified family physician and treated over 10,000 patients before transitioning to focusing full time on his website 22 years ago. It has been the most-visited natural health site on the web for the last 15 years. He’s had many best-selling books, but his latest book on keto, Fat for Fuel, was the number one book sold in the US when it was launched in May of 2017.
Now Dr. Mercola has a new book out called KetoFast, and I’m really looking forward to talking with him about it because when I read it—he sent me an advance review copy—I was pleased to see that his approach to ketogenic diet and intermittent fasting and fasting is very similar to my own and what I’ve arrived at through my own experimentation and also through working with hundreds of patients in this combination of keto and fasting. And he has a lot of the same concerns that I do regarding ongoing ketogenic dieting in many people and in extended water fasting in many people.
And I really love the way that he’s put it together into a cyclical approach, with cycles of intermittent fasting and ketosis, and I think a safer and more tolerable way of getting the benefits of fasting without doing extended water fasting. So hope you enjoy this is much as I did. Let’s dive in.
Chris Kresser: Dr. Joe Mercola, thank you so much for being here. I’ve been looking forward to this for some time.
Joseph Mercola: Well, it’s a great pleasure to be with you. And I want to, before we begin, thank you so much for representing our views on Joe Rogan and really helping the world understand the truth about natural medicine.
Chris Kresser: Oh, thank you for that. It was, it was arduous, but hopefully worth it.
How Dr. Mercola Got Started with Keto and Fasting
Chris Kresser: So I’m excited to talk about fasting, ketogenic diet, and in particular the approach you’ve outlined in your most recent book. And before we do that, I would love to just hear what took you down this road personally. How did you get interested originally in ketogenic diets and fasting and then how did you arrive where you are now?
Joseph Mercola: Well, I was motivated to start keto because of the buzz about it a few years ago, and I wrote a book, Fat for Fuel, several years ago, which actually, the week it was launched, was the best-selling, the number one selling book in the entire country.
Chris Kresser: Awesome.
Joseph Mercola: By the Nielsen ratings. So I was convinced of the value of that approach metabolically and experienced some side effects from starting it myself, and learning by trial and error, I learned there’s some things that you should not do. And then I came to appreciate that fasting, complete multi-day water fasting, typically five days or so, was one of the most powerful metabolic interventions I’d ever seen and witnessed clinically.
And of course, historically, it’s been used for thousands of years, and virtually every major religion on the planet integrates some sort of approach. It seemed to make sense. So I wanted to follow up on my book Fat for Fuel. It was going to combine that with multi-day water fasting, and that was the intention of the book. And when I started to research it, I realized that I was wrong. So I modified it significantly to obtain the most amount of benefit you can with the least amount of work.
Chris Kresser: Right.
Joseph Mercola: Yeah.
Chris Kresser: And potential downsides, which we’ll talk about.
Joseph Mercola: Yeah.
Chris Kresser: Because that’s definitely been my experience as a clinician too. It’s really interesting that when you look at the research on fasting, it’s like a miracle cure.
Joseph Mercola: Yeah, yeah.
Chris Kresser: You can find studies for fasting for just about every chronic disease and from severe autoimmune diseases to cancer to any inflammatory condition. But of course fasting, we can’t do it forever.
Joseph Mercola: No, no, no you can’t. But the most frequently you can, the better benefits you get.
Chris Kresser: Right.
Joseph Mercola: Let me just interrupt by saying that there is one benefit that I neglected to mention in the book, but I realized after writing it is that the fasting benefits on your sleep are extraordinary. Do you wear an Oura ring at all?
Chris Kresser: I do, yeah.
Joseph Mercola: All right, so then you know that when the days that you’re fasting, oh my gosh. Your readiness score goes through the roof.
Chris Kresser: Yeah, it’s pretty incredible. All that tissue repair, which I definitely want to do a deeper dive into that. But you have a section in your book on the history of fasting, which I think is interesting. Because it’s been around for a really long time. You could say it’s maybe one of the original health interventions.
Joseph Mercola: Absolutely, there’s no question. It’s been used for thousands of years. I mean, we’ve got Plato and Hippocrates promoting it 2,000 years ago. And it started in the US about the 1800s with the national hygiene movement.
Chris Kresser: Right.
Joseph Mercola: It didn’t really become popular until Herbert Shelton started and popularized it in 1911, about 100 years ago. And today we’ve got Alan Goldhamer out in your neck of the words in the TrueNorth clinic in Northern California who had fasted more people than anywhere in North America, at 16,000 people, from anywhere from five to 40 days.
Chris Kresser: Yeah. And then there’s a lot of other benefits too, of course. I think for me personally, just looking at my relationship with food, which fasting illuminates, and not cooking and cleaning, I have to say—I appreciate that a lot on a day when I’m busy—I love food probably as much as anybody I know, and cooking and food preparation, and I’m a total foodie. But I have to say that occasionally I just get tired of the whole process.