Last Update: August 25, 2022
Mark Sisson is a household name in healthy living circles, and for good reason. He’s credited with turbocharging the growth of the primal/paleo movement back in 2009, and his original blog, Mark’s Daily Apple, has been the top ranked blog in its category for more than a decade. He has authored numerous books, including Primal Blueprint, The Keto Reset Diet (which made him a New York Times bestselling author in 2017), and The Keto Reset Cookbook. He’s also the founder of Primal Kitchen Foods, a go-to favorite for those pursuing a paleo or keto diet.
We sat down with Sisson here at Thrive Market HQ to learn about his approach to keto. Watch the video for the full interview, and keep reading for some highlights.
I started eating in a paleo way maybe 15 or 20 years ago. I adapted that to my own term: primal blueprint. So now we talk about eating primally, which is basically getting rid of sugars, processed foods, industrial seed oils, things like that, and coming down to a list of real food. Meat, fish, fowl, eggs, nuts, seeds, vegetables, a little bit of fruit, maybe some starchy tubers once in a while.
That was the primal way of eating, and I basically thrived doing that for 15 years. I felt no need to alter my diet in any way, shape, or form. My muscle mass was good. My energy was good. I slept well. My performance was great in athletics. I wasn’t hungry. So I thought, why should I shift things around?
But I’m always chasing performance, and about six years ago, I started reading a lot more about this ketogenic diet. I started paying attention to some of the people in the keto space who were demonstrating excellent results, and I thought, if that’s something out there for me to try, and I’m into experimenting on myself, why don’t I do that?
So I did a little more research, and then I spent two months in a deep keto dive. I was in ketosis for two months. And lo and behold, I noticed a number of benefits that I didn’t think I could accrue, because I was already fine. But I noticed that my energy level improved a little bit. I noticed that I got better sleep, even on shorter hours. I noticed that I was not only losing a little bit more body fat—and I don’t have that much body fat to lose—but I was maintaining and even building a little bit more muscle.
So I thought, if I’m seeing these sorts of results from my point of view, which was “everything is fine, I don’t need to change,” how critical might this be to people who are stuck on their journey, who have had less than rousing success, shall we say, eating traditional paleo or primal ways? Or heaven forbid, on their standard American diet? So, that was the genesis of my looking at doing a book on the ketogenic diet, but one that was a kinder, gentler version.
One of the things I’d noticed about people in the space was that they might be getting great results, but there were reports of sort of extreme efforts to get there—suffering through the keto flu, not feeling that great for a long period of time, hoping that they would emerge on the other side with the results they were seeking. And it seemed to me that there might be an easier way to adopt this way of eating, and to get the benefits that we’re all seeking.
And that really became the main focus of the Keto Reset Diet—to use a ketogenic diet, a ketogenic way of eating, as a means of resetting your metabolism. So not necessarily thinking that you’re going to spend the rest of your life in ketosis, but to use ketosis and time spent in a ketogenic eating strategy to reset your metabolism, to create what we call greater metabolic flexibility. That means the ability of the body to extract energy from whatever substrate is available, whether it’s the fat on your plate of food, the fat stored in your body, the carbohydrate on your plate of food, the glucose in your bloodstream, the glycogen in your muscles, or the ketones that your liver produces. Maybe even the amino acids, in times of scarcity. This metabolic flexibility became kind of my main focus in the goal for the Keto Reset Diet. It is a reset, not necessarily the rest of your life.
So many people today consume a diet that is very high in carbohydrates, very high in processed foods, high in sugar, high in industrial seed oils, and relatively low in healthy fats. All of these elements of that standard American diet can manifest themselves in weight gain, inflammation, lack of energy, increased risk for certain diseases—and that’s not a great position to be in if you’re somebody who’s seeking more energy, and a longer life, and a disease-free life.
So, the problem—among many other problems, but the main problem—is that most people haven’t tapped into their skill of burning fat efficiently. We’re all born with this default setting that allows us to be metabolically flexible, and allows us to derive a lot of energy from our stored body fat. However, early on in our development, our parents will feed us mashed peas, mashed potatoes, crackers, soft carbohydrate foods, and we very quickly get into a pattern where we’re eating a lot of carbohydrates. We’re filling up our glycogen stores, and we’re filling up our fat stores from the excess carbohydrate.
But because we have all this sort of short term energy available in the form of glucose, we never really get a chance to tap into our stored body fat. And so, over time, we develop this physiology that depends on a regular feeding of carbohydrate. Our brain thinks that it only can thrive on glucose. Our workouts are sort of orchestrated around carbohydrate loading, depleting the carbs, and then refilling them later on. And all of this leads to what I call a sugar burner mentality, or sugar burner paradigm, which is: We become really good at burning sugar, carbohydrate, glucose, and not very good at all at burning fat.
The idea of creating metabolic flexibility is one of tapping in to that innate ability that we all have to be efficient and effective at burning fat, creating ketones, using ketones to fuel the brain instead of needing to have glucose or carbohydrate at every meal, two or three, four or five times a day sometimes.
This metabolic flexibility then allows you to have energy at all times, whether or not you’re eating, whether or not you skip a meal. Also, because you’re burning body fat and not burning carbohydrates and stored glucose and glycogen, there’s a reduction in inflammation. That manifests itself in the loss of retained water, for instance.
People will describe going long periods of time without needing to eat, and so that sort of ability to free yourself from the tether of hunger, appetite, and cravings, and to be able to just live your life without having to think about when the next meal is, and having to adjust your schedule around eating times, versus when it’s really convenient to have, say, a meeting, or when it’s convenient to travel. All these things become very empowering when you achieve this metabolic flexibility.
There are many different ways to get into ketosis and to go keto. Probably the most convenient one is to just adjust your macronutrient levels to where you’re consuming 70 percent of your calories in the form of healthy fats; maybe 5 to 10 percent in the form of carbohydrates, depending on your daily caloric needs; and getting adequate amounts of protein.
Adequate amounts of protein for most people is anywhere from 50 grams a day to maybe a maximum of 130 grams, even for the most ardent bodybuilder athlete type. So, that protein requirement is fairly narrow. The carbohydrate restriction is what really what governs this, because for most people, that’s 50 grams of carbs or less. It will pretty much guarantee that your body will start to make these adjustments. When you get above 50 grams, then the body really doesn’t get the message that we’re going to be restricting carbs for a long period of time.
One of the more popular terms in the last five years is this term, intermittent fasting. What does it mean? For some people, it means just going from dinner at 8 p.m. one night to not having breakfast until 10 a.m. the next morning. That’s hardly intermittent fasting—that’s just having a late breakfast.
I do this compressed eating window of 18, 19 hours not eating. I don’t really even consider that intermittent fasting. I think for me, the real fasting aspect of this … [is] fasting to the point where you clearly are encouraging your body to go in and tap into additional body fat stores, where you’re encouraging the body to take advantage of this window and repair damaged tissues.
If you go long enough without eating food and without refilling those energy stores that way, the body turns on certain genes that cause what we call autophagy, and autophagy means “eating self.” It’s basically where a cell will look at damaged proteins and damaged fats within it, and because there’s no other source of energy available, will consume those for energy, and in so doing, clean house, and clean up the debris within itself. There’s even research that suggests that there’s some DNA repair, that certain genes turn on that proofread genetic material, that when it finds damaged strands, will make effort to repair that damage.
In the scientific circles in which I run, we’ve had a saying for the last 20 years: Basically, the less sugar you burn in a lifetime, the healthier you will be and the longer you’ll live. So, the more that we can reduce our dependence on glucose as a means of locomotion, even as a brain fuel—clearly within limits—the better we can become at having metabolic flexibility and burning fat and making ketones, using ketones, offsetting the need to take in carbohydrates to fuel the brain. I think that we trend toward ideal body composition, we trend toward better sleep habits. We probably trend toward a decrease in inflammation, which may manifest itself in terms of heart disease in some people, arthritis in other people. Getting a hold on our inflammation is a critical component of this living better that can come with living a ketogenic diet.
People talk about the flu, and for a lot of people, it’s real. It’s a feeling they get when they embark on a keto eating strategy. The way it happens is, the brain is sort of used to getting a regular supply of glucose every few hours, day in and day out. And if you don’t get that regular supply, you get hangry, right? Or you get moody, or depressed, or you start yelling at your spouse, or whatever it is. That’s a brain that’s become used to a regular supply of glucose, and hasn’t built the metabolic machinery yet to burn ketones.
When you start going into ketosis and you restrict glucose, the brain is going, “Whoa, where’s my glucose? How am I going to function?” And there are some hormonal manifestations of that almost immediately. It’s almost like a stress response. To a brain that’s used to getting glucose and now doesn’t get glucose, there’s the tendency to secrete hormones that cause the adrenals to release cortisone and epinephrine, and kind of take emergency action, some of which is to tear down muscle tissue, to send the amino acids from the muscle to the liver to become glucose, so the glucose can be used to power the brain.
And this is a transition period for a lot of people—a couple of days where, again, the brain hasn’t yet become used to burning ketones, doesn’t know how to do it, but as it becomes more and more comfortable, and as the liver starts pumping out these ketones, you get past that hazy brain fog, and that hangry couple of days, and then you emerge into this wonderful light and clarity, and great energy. But it’s not pleasant for a lot of people.
In the Keto Reset Diet, one of the ways that we use to sort of circumvent this keto flu is that we spend three weeks just getting rid of the crap. Just going what we call primal. So you’re not keto yet, but you can be getting rid of extra sugars, sweetened beverages, pies, cakes, candies, cookies, breads, pasta, cereal. I know it sounds a little bit daunting. You’re getting rid of the industrial seed oils. But you’re not restricting calories, so you’re not allowing yourself to go hungry ever. That’s one of the secrets: Just don’t let yourself get hungry. Surround yourself with healthy snacks.
And then after three weeks, the brain and the body have already started to get used to the fact that there’s not going to be 300, 400 grams of carbs every day. At most, there’s going to be 120, 150. And that’s plenty of carbs for anybody, regardless of what your activity level is, or anything else.
At the end of three weeks, then we say: Now, if you can wake up in the morning and you have enough energy to go a couple of hours without eating breakfast, that’s a sign that you’re burning fat. If you have enough energy to go do a workout, and not have a pre-workout meal or a post-workout meal 20 minutes after, that’s a sign that you’re getting better at burning fat.
Ready to start your keto journey? Shop Mark Sisson’s keto kit on Thrive Market now!
For more, check out our ultimate guide to the keto diet!
Download the app for easy shopping on the go
By providing your mobile number, you agree to receive marketing text messages from Thrive Market. Consent not a condition to purchase. Msg & data rates apply. Msg frequency varies. Reply HELP for help and STOP to cancel.