How To Use Fasting For Longevity And Energy with Joel Kahn, MD

Content By: Ari Whitten

How to use fasting for longevity and energy with Dr. Joel Kahn, MD. Fasting can make you live longer, help you lose weight, heal faster, and increase your energy levels.

Is that all just hype, or is there actually science that backs it all up?

Today, I am talking to Joel Kahn, MD, an integrative cardiologist, who has adopted fasting as a part of his treatment plan for his patients.

Dr. Kahn has been practicing cardiology since he graduated from the University of Michigan, Ann Arbor in 1983.

He is the owner of the Kahn Center For Cardiac Longevity and a professor at Wayne State University School of Medicine and Oakland University Beaumont School of Medicine.

He spends most of his time teaching his patients and students about how they, by adopting a lifestyle that is plant-based and incorporates fasting, can live a life filled with energy and prevent future heart attacks.

In this podcast, you will learn more about

  • How Dr. Kahn helps his patients prevent future heart attacks
  • What the fasting-mimicking diet is
  • How the fasting-mimicking diet can help you lower your risk of cancer, lower your blood pressure, and boost your energy

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How To Use Fasting For Longevity And Energy Show Notes

What caused Dr. Kahn to become a cardiologist (0:26)
How lifestyle is influencing atherosclerosis (1:38)
Who Dr. Kahn typically sees in his practice (3:27)
How the medical system fails at preventing disease (3:34)
Why it is important to identify the root cause of the disease before giving medication (5:35)
How Dr. Kahn lives his life (7:12)
How Dr. Kahn starts treatment of his patients (7:40)
What it was that shifted Dr. Khan’s approach to treating patients (9:36)
How Nutri-Technology can extend longevity (11:45)
Why Valter Longo believes water fasting is stressful for the body and what he did to counter it (12;41)
What Dr. Kahn’s experience is with fasting-mimicking diet is (14:58)
How some high-protein diets can activate the mTOR (16:47)
The benefits of the 5-day fasting-mimicking diet (17:24)
Dr. Kahn’s amazing results of adding the fasting-mimicking diet to his routine (19:47)
What the difference is between the fasting-mimicking diet and other fasting diets is (21:44)
How the 5-day fasting meal plan for people with MS have decreased the symptoms in patients (24:34)
How the fasting-mimicking diet can change cancer cells (25:24)
Who should proceed with caution when wanting to start on the fasting-mimicking diet (26:21)
How the fasting mimicking diet is a form of hormesis (26:51)
How the human being has been developed to undergo period with fasting (29:09)
One of the biggest challenges Dr. Kahn experience with his patients when it comes to the fasting-mimicking diet (30:53)
How Dr. Kahn helps patients release up to 10 pounds of fat by following the 5-day fasting-mimicking diet (32:10)
What the science says about fasting and what Dr. Kahn’s take on that is (33:14)
How to get the best result for the other 25 days (35:28)
How to learn more about the work Dr. Kahn does (36:49)


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Studies Show Intermittent Fasting Promotes Longevity And Energy

Ari Whitten: Thank you, Dr. Kahn for joining me here and I really appreciate you being here and I would love if you could just get started by telling us a bit about your background in medicine and how you got started.

Dr. Joel Kahn: Sure and thank you, it’s a pleasure and I know we’re gonna be hanging out together at a conference soon, which will be a ton of fun.

Ari Whitten: Yeah.

What caused Dr. Kahn to become a cardiologist

Dr. Joel Kahn: I grew up in suburban Detroit, which is where I am standing right now and got into medical school early in Ann Arbor University in Michigan, they have one of these entrance programs, right out of high school you were accepted into a six year program, and I knew I wanted to be a heart doctor.

I had a little murmur as a kid, it kind of fascinated me, it was no big deal, but I was always around equipment and tests.

Actually, two things happened the first day I got into med school at age 18, and I adopted a plant based diet at age 18 because the cafeteria at my dorm was so disgusting.

I didn’t have any ethical issues, I didn’t have any environmental issues, I had survival genes telling me, “Go to the salad bar!” and it’s 40 years later and I still eat plant based and as I got deeper into medicine and all, and hang out with cool people in San Diego and LA that care passionately about animals and environment and the whole explosion of the plant based food industry, and it has become a core of what I do in practice, plus I own a restaurant and this and that, but I went on to training cardiology in Dallas, Texas.

Kansas City I learned about how to put balloons and stents in any artery in your body and 1990, I came back to Michigan to start practicing.

How lifestyle is influencing atherosclerosis

Three weeks after I opened, put my shingle up with some other docs, Dean Ornish published this kind of seminal paper called the Lifestyle Heart Trial, showing that a combination of lifestyle features of exercise, social support, mind body practices like yoga and a plant, strong plant based diet.

He documented for reverse atherosclerosis, and “Whoa, I’ve been eating this way, because it was my survival response, but there’s actually …” Nobody knew, there were little suggestions going back decades. Nobody knew that it might be possible to reverse decades of an atherosclerosis life style

Ari Whitten: Yeah, yeah, that’s cool that you were doing it even before Ornish published his stuff-

Dr. Joel Kahn: So, yeah, I think I’m the only cardiologist in Southeast Michigan that read that paper. It was in Lancet, I mean, that’s a premier medical journal. So that was pretty cool. I’m doing this and so I teach some other people what I do and I’m pretty much set and send that. I’ve been in the cath lab, I treat heart attacks, I put in stents, while I’ll talk to you more about your radicchio salad while you’re under my care.

I find when I’m putting needles in people they pay attention to lifestyle recommendations a lot more than in other settings. I have a really preventive integrated cardiology practice, rather unique, using advanced testing on carotids and arteries and use lots of supplements and that stuff. I write books, do blogs and I have fun, but I do have a restaurant in town with my son and a food truck and a food dispensary, so we’re…

Ari Whitten: Oh, fun.

Dr. Joel Kahn: This growing world of health awareness and I think we hit rock bottom, so it’s all up from here.

Ari Whitten: Cool, so for people who are not necessarily aware of what a traditional cardiologist might do, could you maybe elaborate a bit on kind of what traditional cardiologists do and what you’re doing differently?

Who Dr. Kahn typically sees in his practice

Dr. Joel Kahn: Yeah so …

Ari Whitten: Or what you have been doing differently?

Dr. Joel Kahn: The person you rarely see is the person I mainly see. People come in my clinic and I say, “Why are you here?” And they say, “I have nothing wrong with me but heart disease is everywhere, check me out.” Because there is not built into medicine the same early detection philosophy that exists for breast cancer and mammograms, colon cancer, colonoscopy, stool samples.

It just doesn’t exist and there is the ability between blood work and some direct testing that’s become very inexpensive and very accessible.

Anybody age 40 over and a few people under 40 if they’re really high-risk family or diabetic or crazy cholesterol if they wanna know if they’re aging on track or aging inappropriately and aggressively the answer is at hand and for a few hundred dollars everybody can find out.

But it’s not built in and it’s not on billboards and hospitals don’t promote it, generally. So usually, a cardiologist will see somebody. Could be high blood pressure, could be high cholesterol. It’s usually, “I had a stress test, my primary Dr. ordered it and it wasn’t right and I have palpitations or shortness of breath.”

How the medical system fails at preventing disease

Usually, if they really have heart disease, because some of that’s anxiety and other issues, but you’re picking them up at the end of the road if that proves to be heart disease and it’s a bad model. You’re picking people up after five, 10 years of progressive, silent problem.

Dr. Dean Ornish isn’t the only one, I mentioned his name twice now. There was a physician in the ’40s and ’50s, Dennis Burkitt, English physician that lived in Africa most of his career, there is something called Burkitt’s Lymphoma, named after him. He used the analogy that the sink faucet’s on and over flowing. The medical system is great at mopping up the floor, which is patients showing up at the emergency room at the end stage as nobody thinks of turning off the faucet.

It’s my gut feeling with people’s lifestyle and early detection and that analogy still holds unfortunately with all the advancements in medical practice. Something like under 5% of all dollars in the world on healthcare are on prevention and 95% [inaudible].

Ari Whitten: That’s insane.

Why it is important to identify the root cause of the disease before giving medication

Dr. Joel Kahn: You’re falling off the waterfall and doctors are operating, stenting, bypass, lifelong eight prescriptions and all that stuff can have its place. I’m not a total anti-medicine basher, I’m still in that system. I’m a professor at a University, but it’s just logical, let’s go upstream and trying to identify the lifestyle, the genetics, the inflammation and correct all that as well as actually characterize if you already have the problem or not.

Because it’s a silent disease. Heart disease, most people find out the day they have their heart attack or die, that they’ve had a problem for five, 10 years and it was missed, because the system doesn’t teach us to pick it up.

One of the greatest quotes I’ve ever heard, and it’s very provocative, is, “A heart attack after age 80 is God’s will, a heart attack before age 80 is a failure of the medical system.” Really provocative, but that was actually 1955.

That was Dwight Eisenhower’s cardiologist who already had the sense, we should be able to identify people who are on their path to a heart attack. Were just figuring out smoking, cholesterol, blood sugar and this wasn’t just aging, it was at least to a large degree lifestyle related.

So yeah, it’s a failure of the medical system, so it pisses me off. Families suffer, patients suffer, businesses suffer when their executives die, and it could be cut short and it’s not like you have to spend $100,000. It’s accessible. It’s just nobody is teaching it with some exception.

Ari Whitten: Yeah, so how long have you been in practice prior to this?

Dr. Joel Kahn: Med school, graduated in ’83, so in some sense, now that’s 34 years, but fully out 27 years. 1990 …

Ari Whitten: Wow.

How Dr. Kahn lives his life

Dr. Joel Kahn: And I have a vibrant life, I’m really high energy guy. I do about eight things a day. Lot of energy. I contribute some of that to passion and love for what I’m doing. Some of that’s a very clean diet and some mind body yoga and infrared sauna and a good relationship, with a marriage of 36 years, that provides stability and love and support and some great rescue dogs. All the other things, I do grounding and earthing and anything that’ll energize my body and give me some great electron flow, I’m all for.

How Dr. Kahn starts treatment of his patients

Ari Whitten: Beautiful. Now, I know from some conversations that we’ve had outside of this interview, that something was missing in your practice. What was that? What was missing in your practice?

Dr. Joel Kahn: Doctors take a history, do a physical, look at some lab data, EKGs, we have prescription drugs, which I use far less than most cardiologists, but there’s a time and a need and I press some stents. That’s really the menu for standard cardiology. I had added in mind body, advanced lab work, some supplements that are appropriate at times, CoQ10 and others, there’s an unlimited number that could help certain people. Personalized medicine.

When it came to nutrition and diet, I would ask people to explore the world of plant-based life, whether it’s 50%, 80%, 90% or 100% of the way that they select their food.

Watch Forks Over Knives, read a book by Dr. Esselstyn or Ornish or something, and many of them would just get it. They knew they had to clean up their diet. I didn’t have a weight program, I didn’t have a really powerful anti-inflammatory program, and a program I don’t have a name program, I don’t need the name the ones that people pay others who charge, nutritionists, Marie Osmond, when you turn on the TV you can’t help but see the ads.

That’s not something when I’ve ever studied the ingredients I’d ever have in my practice because it’s chemical warfare. Sorry Marie, I love you, I like your brother a little better, but anyways… but anyways, I didn’t have that kind of program and I really wasn’t looking for it, but it sort of fell in my lap about six months ago and it all leads to better health and energy.

To answer your question, I didn’t have that kind of scientifically-based weight management that might merge with my main interest, which was longevity. Hacking your body and your genetics and your metabolism too, to have the best life and the most energetic life.

What it was that shifted Dr. Khan’s approach to treating patients

Ari Whitten: What shifted for you? What did you become aware of that made things shift and how did you change your practice at that point?

Dr. Joel Kahn: Sure. Over the last four, five years my clinic is called the Kahn Center For Cardiac Longevity, it’s a little bit of a bold name. What are you doing that? But because of that and my interests, I’ve been reading the researchers, a Dr. Aubrey de Gray. Some people may know a Ph.D. with the best beard in all of science.

There’s a guy in New York, Dr. Nir Barzilai, who’s a professor of aging, but really, the coolest dude on the street is a professor at USC in Los Angeles, Dr. Valter Longo. V for Valter, he’s an Italian from Genua, still quite young, he’s under 50, and I just have seen his name and read his papers. Very heavy science for 20 years.

In fact, he’s credited some of the most essential pathways that are described that are resulting in aging of cells in models like yeast in mice and humans. He described their varied pathways, so if anybody’s heard of the mTOR pathway, or rapamycin inhibiting the mTOR pathway.

There was no mTOR pathway, DR. Longo described that and showed how that accelerated activity of mTOR and may lead to cell death and aging.

What wasn’t known to me till January, when I was listening to him answer questions. I was listening to a podcast and he was being interviewed and he started talking about his more than decade-long interest in fasting as a tool to reverse the pathways he had identified originally that promote aging, he was looking for a natural non-pharmacologic way to interrupt those aging pathways and I did not realize his mentor 22 years ago was one of the docs in the Biosphere 2, when they locked themselves up, and although I don’t know that they planned a fast, they had so little food and they came out anorectic, but they actually had one of the best experiences in fasting or best or most scientifically studied, actually human experiences for fasting …

Ari Whitten: Oh I didn’t know that.

How Nutri-Technology can extend longevity

Dr. Joel Kahn: [crosstalk] interested, and then he kind of walked away from fasting researched to concentrate on his basic molecular biology. About a decade ago, brought his early interest in fasting back to ask the question, “Can you create an ideal?”

He calls it nutri-technology. Using nutrition as a technology to interrupt these pathways to promote healing, regeneration, rejuvenation, high energy and maybe extend life, so he was playing around and found he can make yeast live 10 times longer by changing the chow, or whatever you feed yeast.

He could make mice live nearly twice as long, by changing the constituents of what they fed them. No drug, no gene therapy, no [inaudible], nothing, just food. Then he took a leap of faith to say maybe these pathways are human pathways and will respond too, and lo and behold in the last three, four years a flurry of publications that show you can create a diet that …

Why Valter Longo believes water fasting is stressful for the body and what he did to counter it

And in fact, one of his leading principles is that extreme stress is not where he wanted to be. Water fasting, which some people find extremely useful and there’s clinics and a whole kind of philosophy of using water-only fasting for one or two or three weeks, medically supervised, there’s probably four, five, six dozen doctors around the country certified in that.

Probably the most famous place is True North Clinic in Santa Rosa, CA, Dr. Allan Goldhammer.

Longo’s philosophy is too stressful, not appropriate for the elderly, not appropriate for the frail. He’s just not a big fan, your white cells go down as you fast, he was worried about what long-term water fasting does to immune function. That was his perspective. He was looking at a way …

He created a menu, that gave the biochemical and metabolic benefits of complete fasting yet you could eat a sizable amount of calories. It actually it’s called a fasting mimicking diet.

Get the benefits, get the weight, get the fat loss, get the inflammatory benefits, yet you can function, you can eat, you don’t need medical supervision, and lo and behold it was already a business that USC had incorporated and launched as kind of a start-up and I jumped in. I said, “I gotta get this, I gotta do this.”

I’ve been using this, it’s basically five days a month of a prescribed menu that actually comes in a box and the other 25 days a month do what you want, which, again, Longo’s philosophy was doing something two days a week or every other day it means your whole life is dominated by this focus on this specific fasting, but here you can do five days dedicated to your health, longevity, rejuvenation and 25 days eat whatever you define as healthy.

It’d probably not a good idea to have to Burger King everyday if you’re really [inaudible] longevity. Maybe one day will see a little better menu there, but it’s not so awesome right now.

It’s become very easy. It’s the easiest thing I’ve ever done. I’d seen some phenomenal results personally in energy, vitality, vibrancy, but I have now several hundred patients that will attest and many thousands that have been enjoying this, plus a whole bunch of interesting branches, where fasting-mimicking diets are taking off or other disease conditions and just well being.

What Dr. Kahn’s experience is with fasting-mimicing diet is

Ari Whitten: I would love to get a little deeper a far as your experience with it and the results that you’ve been seeing in your clinic, but I’m actually really curious on the mechanisms of how it’s possible to still eat, but still kind of create this fasting physiology and get a lot of the benefits of that physiology.

My understanding and I know there’s some debate among various researchers on this. Some people are really, really strict and say, “If you consume anything other than water, you’re disrupting fasting physiology.” Other people are a little looser, I would say I’m a little looser as far as saying, maybe certain things like herbs or greens or squeezing some lime into water is not gonna disrupt fasting physiology to a significant degree, but this is kind of another step beyond even something that I had considered, which is that it’s possible to consume a pretty significant amount of food and pretty sizeable variety of different foods and yet still get the benefits of fasting, so how does that work?

Dr. Joel Kahn: You know, it was a decade-long experience of testing and very frankly I know there hasn’t been any human experiment. Take a group of humans and a five-day complete water fast. Take a group and do a five-day fasting mimicking diet and see. It may be that you’re getting 60% to 70% of the benefit versus a water fast, it may not be. I don’t think that’s actually been tested. I think it was more, he thought that was off the table, it was something not very practical. You can’t sell a box of nothing to a person and call it a start-up from USC, that’d be a great idea, the fasting box.

You open it and it’s empty.

Ari Whitten: The over head is low.

How some high-protein diets can activate the mTOR

Dr. Joel Kahn: I think part of it and I’m jumping into water that I’m familiar with, but probably not the world’s expert on. A part of it is the macronutrient mix. Certain high protein diets tend to activate mTOR pathway. High-protein diets tend to activate what’s called the Ras PKA pathway, another pathway Dr. Longo described, and it’s particular to amino acids, methionine, and leucine, which some people are using in sports supplements, brand chain amino acids supplements, and it’s naturally gonna be in many animal products, meat products.

The benefits of the 5-day fasting-mimicing diet

This is a very low protein mix. It’s actually, there’s no added sugar, very low added sugar. Just everybody would agree that’s where we need to be, but it’s a relatively low carbohydrate, a solely complex carbohydrate.

But it is actually a surprisingly high natural fat content. 60, 70 maybe plus percent of calories from olives, walnuts, [inaudible], there’s no oils. It’s soup mixes, it’s bars, nut bars, it’s actually bags with fiber, six green olives from southern Spain.

It actually, you will get ketonic if you measure it, but third, fourth, fifth day from eating 800, 900 calories a day, but it’s a plant-based play because it’s plant-based.

It’s a plant-based play, they may be mimic a bit the physiology of a low carb diet that most people are gonna be doing with animal products. Some data that if you’re gonna do that, plant-based may be a better player.

There’s been some studies out there for a while called eco-Atkins from a researcher in Toronto, David Jenkins, that talk about benefits of a plant-based ketosis. Plenty of other data that there is a difference between animal protein and plant protein, but it’s low protein overall.

So some of it is the specific ingredients that it’s a Mediterranean style diet. For example, there’s many teas, but there’s only hibiscus, spearmint, and lemon. There’s quite a bit of data, the antioxidant power of hibiscus being unique over other teas. It’s in fact, it’s even higher antioxidant than green tea, there is no green tea in this.

Spearmint, there’s some data about its antioxidant power and cognitive-boosting ability. It’s not unique to this program, but spearmint’s included. And you know, why spearmint and why isn’t there matcha?

Because he played with these in animals, found differences.

So I mean, there’s quite a bit of spice lot of data, ginger, and turmeric, and such, activating anti-inflammatory pathways. It could have been a bust, and then the human study was done. It could have not mimicked whatever was found in yeast and mice, but indeed it did quite closely in fact, and we can compare those results that I’ve tested myself plus more importantly, there’s a randomized study that was published in February this year in a premier peer-reviewed journal, it’s pretty definitive on what you might expect as results.

Dr. Kahn’s amazing results of adding the fasting-mimicking diet to his routine

Ari Whitten: Yeah, please. So, tell us a bit about what those results were and what your clinical experience [crosstalk].

Dr. Joel Kahn: Well, I’ll start with me first, just briefly. I know one doesn’t mean much if there weren’t science behind it, but I’ve been plant-based vegan for 40 years, I always carried a few extra pounds, I was a chubby kid, I wore a husky bah mitzvah suit. I think I’ve learned in the last five months if you view excellent food as a source of nutrients, you might want to overeat them because then there’s more fiber, more magnesium, more you know, more quercetin in my onions, and you know, too much.

Plus, there’s kind of this philosophy in the plant-based world that it’s not about restriction, it’s about abundance. We all know there’s some chubby vegans, and they’re not all eating chick-nuggets, some of them are just eating real, quality, whole food plant-based and maybe just overeating.

I’ve lost 22 pounds in five months, and it was without an effort. I’m just telling you. I call myself the FMD whisperer. I just talk about this stuff and I think I lose a pound. But it’s interesting because it’s really not … and nobody’s probably going to lose 100 pounds even if you did it over and over. That’s unknown.

This is a program where a 350-pound person who wants to do it every four weeks, are not tested. When I talk to the team that put this together, they say probably not going to happen, but I think for many people, the 10, 15, 18-pound weight loss is very, very doable, and I’ve had patients lose 10 pounds in five days. I don’t think it’s water weight, it’s really …

So, that’s one, and lots of energy. Great sleep. Whether my skin is more glowing or not, I don’t know, people tell me that. They have data that that’s actually a reasonable application.

It’s a gluten-free menu too, for those who care about that, and a lot of people care about that. I’ve seen my LDL drop, [inaudible] C-reactive protein was already low but it dropped. I didn’t measure it all the time, but the published data.

What the difference is between the fasting-mimicking diet and other fasting diets is

The last thing is, well, I’ll tell you right now, they have data, and why is this different than the fast diet in England, the 5:2 diet, or once a week?

So, Dr. Longo’s data is if you were to restrict calories and become suddenly ketotic in the calorie mix that he’s created, on the third, the fourth, the fifth day in a row, you’re getting some responses you don’t get twice a week or once a week, including a drop in IGF-1, a tumor marker often associated with breast cancer, prostate cancer, colon cancer. IGF-1 drops, and I documented that on myself. I was low, but it dropped more after three cycles, three months.

Stem cells, so, white count tends to fall during the fast, but the sixth day, five days on, the sixth day, you’re supposed to slowly re-feed with some soups, with some juices, kind of soft foods for the sixth day. Re-feeding’s important. They’re actually, your white cells start to go back up and when you do the proper analysis, I haven’t done it on myself, but published does, it’s a population of very young white cells including some stem cells showing up in your blood stream that have the potential to go to places of injury and heal, repair, rejuvenate injured tissue.

Personally, I had a terrible plantar fasciitis, that just would not go right. Two months gone, no shoulder pain, I don’t know what it is but it’s gone. These sound kind of religious, so you know, move away from my personal experience.

The published data is blood pressure, and my blood pressure dropped 20 systolic, and I was struggling at age 15 and a half. I would have to sneak in a little ramipril and Advil. Anybody I’m on a prescription drug is right now I’m drug-free. My systolic pressure has dropped 20 points with food. Very remarkable. I really didn’t think that was gonna happen.

The published data in 100 patients randomized or standardized on this five-day program once a month for three months is C-reactive protein, blood pressure, cholesterol, blood sugar. Maybe more importantly, total body weight down, visceral fat down, lean body mass not down, in fact, lean body mass up a little bit in these studies, measured [inaudible] skin and other things. Then IGF-1 went down and stem cell production up for a few days on re-feeding and afterward.

But with generally reported increase of vitality, increased energy, good sleep, and you’re not really hangry, ’cause 800 to 1,000 calories a day is enough, maybe you know, you’re probably not going to want to do the workout that they … or light walking, or a light treadmill walking workout, but lots of energy, lots of ability to function.

Unlike a water fast, where you’re probably going to really want to have five days where you’re nearly non-functioning. Well, this is for most people, not super humans like you. [crosstalk] five-day water fast, instead do a workout.

How the 5-day fasting meal plan for people with MS have decreased the symptoms in patients

There is some ancillary data that’s fascinating. There’s some animal studies where models of multiple sclerosis have shown that actually with a slightly lower version of this program, but the same calorie mix, no protein, no added sugar, complex carb relatively low, high healthy fats, that they’re actually documenting regrowth of myelin sheaths on exons, and decreased symptoms, and a human trial that so far has only shown improved symptoms of multiple sclerosis. They haven’t done nerve biopsies to match what we’re seeing in animals.

There’s animal studies and a human trial on cognitive function, executive function, EDMP production, all favoring improved cognitive function after three cycles, so that’s …

How the fasting-mimicking diet can change cancer cells

Maybe one of the coolest differentials is there have been studies both basic and now human, that there’s a differential response to cancer cells and normal cells to this plant-based ketotic fasting-mimicking diet.

Cancer cells actually seem to change their physiology to be more sensitive to chemotherapy and there’s a higher kill off cancer cells and a lower kill of healthy natural cells you’d like to actually kind of separate the populations based on the response to the stress of fasting or ketosis.

There’s a four-day program if you’re getting chemo for breast cancer and you eat this program during that, you may get less side effect and more response, and there actually are products being developed being Chemolieve I think it’s called for chemo, and MS and brain diseases, so a really exploding field of this nutri-technology, and you know, flipping a metabolic switch using ketosis, but eliminating the sort of risk.

Who should proceed with caution when wanting to start on the fasting-mimicking diet

Who shouldn’t do it? Underweight people shouldn’t do it, type 1 diabetics, be very concerned about. Type 2 would have to be work with their physician, be very knowledgeable, probably shouldn’t take the medicines because blood sugar drops and they may get quite symptomatic by lowering their diet and developing some ketosis, so gotta be very, very careful on those, but on my advanced heart failure patients, I’m going to … It is still a stress, they’re going to get a little bit ketonic and it may not be right for them.

How the fasting mimicking diet is a form of hormesis

Ari Whitten: Yeah, you know, I’m glad you mentioned that because one of my big areas of interest and a huge focus of my work is this concept of hormesis.

Dr. Joel Kahn: Yeah, this is all a hormetic play.

Ari Whitten: Right. And for those that don’t know, this is the concept of a temporary metabolic stress basically inducing adaptations in the organism that actually confer benefits. So, increased resilience to stress, and that can translate on the cellular level to things like an increase in the cellular antioxidant and anti-inflammatory defense systems, increase in mitochondrial size and power, and a number of other different potential types of benefits depending on the specific type of stress.

One of the things that seems to be interesting, and that even I don’t really understand that well as someone who’s really delved into the hormesis research really deeply is this idea that hormesis mechanisms seem to kind of induce this response in the body where it almost relearns how to heal.

I was discussing with this researcher here in San Diego, UCSD, this lab for mitochondrial medicine, he does a lot of research on mitochondria obviously, but some relating to hormesis, and one of the things he talks about is this idea of, you’re teaching the body, or re-teaching the body how to heal itself again, and through this temporary stress.

As I’m listening to you describe some of the mechanisms that they’ve identified with this fasting as far as you get this temporary drop in blood cell count, and then you sort of revive the white blood cells, they’re younger, and then you get stem cells floating around, and it’s an interesting phenomenon, right? That by inducing this temporary stress, the body kind of regenerates, and heals itself.

Dr. Joel Kahn: Absolutely, it’s fascinating. When we exercise, as you know, some people will talk about having injury and repair, and ultimately end up stronger at the end of the road if you don’t hurt yourself by regular exercise, and you know, whether it’s cryotherapy. There’s a lot of different things that I’ll do to induce a hormetic response.

I think this food program is a mild to moderate stress, purposely designed not to be extreme.

How the human being has been developed to undergo period with fasting

What’s really interesting is the universality of it, that actually the responses are very similar in a single cell organism called a yeast or a small mammal called a mouse through the complex human beings that we are, and they are primitive, but we are adapted to undergo periods of deprivation, starvation, and activate these pathways of protection and we don’t in our current society, because we overeat, and we under exercise, and bringing them back in.

I think this is the real caveman play. Rather than a complete fast, we use this scientifically studied, fasting mimicking diet. We really are bringing out this caveman reflexes that are universal. Very good.

Ari Whitten: Yeah, absolutely. There’s some interesting …

Dr. Joel Kahn: Can you imagine if you can regrow myelin sheaths and then that’s a mouse model with some supportive data from human symptom response, it’s got to be verified with MRI and other mechanisms, but God, that’s real restorative, you know.

Ari Whitten: Yeah, absolutely. It’s quite a paradigm shift for people to wrap their head around this. First, the idea that doing something which is “stressful”, given how much negative stigma we associate with the word “stress”, we have to wrap our head around the idea that something that’s stressful for our body temporarily is actually conferring health benefits, and then you know, beyond that, it’s just kind of an amazing thing that you’re doing something that’s stressful, that’s conferring health benefits and yeah.

It’s kind of a remarkable phenomenon.

One of the biggest challenges Dr. Kahn experience with his patients when it comes to the fasting-mimicking diet

Dr. Joel Kahn: You and I and 2% of the population have heard the word “hormesis” not being pompous about it, but yeah, there’s a great opportunity to teach and there’s different tools we have to kind of activate those pathways. I again, I just can’t talk about the simplicity of this. The toughest thing for all my patients, finding five days they’re not eating out, they’re not going out, they’re not at the country. Wherever they are, they can dedicate five days to eating a prescribed proof program like this.

Ari Whitten: Right, yeah. You know, I spaced out there a second ago. I was going to say something and I forgot, but what I was going to say is, the first thing is, you have to wrap your head around this idea that doing something that’s stressful has benefits, and then what you were getting at is that we’re biologically adapted to these periods of food scarcity or food absence.

Then, it kind of … You’re creating a paradigm that says the absence of a stress is actually a stress. The absence of a stress is actually a pathological stressor. By always feeding yourself and avoiding this temporary stressor or having food scarcity, you’re actually creating a pathological, chronic stress on the body. It’s kind of a weird flip of things.

How Dr. Kahn helps patients release up to 10 pounds of fat by following the 5-day fasting-mimicking diet

Dr. Joel Kahn: It gets into, you know, many people are aware that it may be of value just to go 12 hours a day without eating, 14 hours a day. We’re always breaking down, metabolizing, catabolism, we’re not going to ever give our body a chance to repair, which is also counterintuitive.

You’re telling me, you know, eating a kale salad at 10:30 at night is actually not good for me? It may actually not be optimal that time of night if you’re having to rev up your metabolism and we’re going to eat at seven in the morning. These are counterintuitive, but they’re very powerful very primitive and just for those of you watching, have you ever seen this model, Ari?

Ari Whitten: Yeah.

Dr. Joel Kahn: This is five pounds of visceral fat. This is the average weight loss you get with five days of fasting-mimicking diet, but some higher. I’ve had people lose 10 to 12, some lose two or three, but one, it’s very heavy, and two, this is such a powerful little tool that I use to motivate people, and they succeed, and it’s one of the first times it’s succeeded with flipping the switch that promotes health.

What the science says about fasting and what Dr. Kahn’s take on that is

Ari Whitten: Beautiful. You know, one last question for you. I’m an advocate of various types of intermittent fasting, and I’m kind of, I would say, loose with my recommendations, meaning I didn’t have one specific intermittent fasting type protocol that I said, “This is the right way to do it, this is the only way to do it,” because I’ve looked at the evidence as it stands right now, and there just isn’t a consensus about, you know, oh, the 5:2 is the best way, are doing a daily 16 hour fasting window, or doing whatever type of variation of fasting, and there’s so many different ones that we can talk about.

There isn’t this consensus that says this is the best way to do it because we’ve tested them all versus each other.

So I’m kind of like, do what works for you, just incorporate some kind of principle of occasional fasting in whatever way that’s sustainable for you. After listening to you talk about Dr. Longo’s research and all the experimentation that went into it, I’m wondering if you and if they are pretty convinced that this method, this approach to fasting, is the best way of doing it.

Dr. Joel Kahn: I think the answer would be number one, it’s probably the most scientifically supported right now compared to others. There’s data, and the Calorie Restriction Society has some published data following I don’t know, about 50,000 people that dedicated… but it’s again, you can’t have 25 days of a same diet in that kind of program. The beauty of this is, would you give up five days a month of a somewhat restricted menu, have 25 days a month, you eat enjoyable but sensibly, and have no restriction. I think it’s a much more doable program, and it’s the most scientifically supported.

Is this the pinnacle and we’ll never improve upon in well-met form and in fasting-mimicking diets and in [inaudible] activation, create [inaudible]? The answer is all these things would have to be studied separately, so I think it’s pretty unique right now that it’s a non-prescription, non-pharmaceutical food play that has really 20 plus years of research behind it. I don’t know how we can do better than that.

How to get the best result of the rest of the month

I will say what’s really interesting, last comment I have to offer, what do you do the other 25 days, and I’m not talking vegan, paleo, Mediterranean, you know, put any label on that. Do you do intermittent fasting on those 25 days? Do you eat eight hours a day and get some sleep not eating? I think there is, I’ve experienced this strongly and my patients report it to me, I’ve not gone five days eating 800 calories a day very often. I do Yom Kippur, I don’t do any, and I’ve done a lot of days of one day, so to be able to go five days in relatively less food creates a viewpoint and a freedom and a psychology that, “Hey, I don’t need so much the other 25 days,” so many, many people have started to apply two meals a day for the other 25 days, not restricted. Not limited, not a specific calorie and macro-nutrient combination.

I know Dr. Longo eats breakfast and dinner and skips lunch routinely. He has part of his, in the long term play, in between using this program. Dr. Nir Basali in New York does lunch and dinner, and a lot of people are limiting that, so I’ve adopted all that, and it may be exactly right to use some of those other varying plans over the 25 days to maintain the benefit, maintain the right … ‘Cause I’ve been able to keep that off without going back to this program very often.

How to learn more about the work Dr. Kahn does

Ari Whitten: Beautiful. Well, thank you so much for sharing all the research around this, and if somebody wants to start doing this, or somebody wants to learn more about your work, or more about this approach to fasting, where should they go?

Dr. Joel Kahn: I’m found at my website,,, and probably the best site would be I mean, the start-up, which it’s not my business, is Prolon,, FMD for Fasting-Mimicking Diet, or frankly Google Valter Longo, he has been giving a series of talks all over the world, a couple of podcasts, very, very interesting 20 plus year history of how he got to here, and how he got clinicians like me to just introduce it in practice as, “Before you’re going to get a blood pressure drug from me, you’re going to do this,” and people are seeing the same results I did. That’s fairly revolutionary introduction of what we should be doing is optimizing lifestyle before committing to lifelong prescription medication in many cases.

Ari Whitten: Absolutely, and I think that’s a good note to finish on. Thank you so much, Dr. Kahn, it was an absolute pleasure interviewing you, and this is great stuff that I think my audience is going to love, so thank you.

Dr. Joel Kahn: Keep up the energy work.

Ari Whitten: Yeah, and I look forward to hanging out with you in a couple of days.

Dr. Joel Kahn: All right, thanks.

Ari Whitten: All right, take care, man.



To learn more about the work Dr. Kahn does go to check out his website.

You can find out more about the company that offers the 5-day Fasting-mimicking diet meal package  US based individuals, go here. UK based individuals, go here.

If you want to know more about weight loss and how that can influence on your energy levels, go check out my interview with Dr. Susan Pierce Thompson: Fatigue while dieting? Here is why, and how to fix it.

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