>> Hi.

I'm Lewis Howes, New York Times best-selling author and entrepreneur, and welcome to "The School of Greatness," where we interview the most influential minds in the world to inspire you to live your best life today.

In this episode, Dr. Casey Means, a leading expert in metabolic health and co-founder of Levels Health, joins us to discuss the key signs of poor health and how to fix them.

We dive into the importance of metabolic health, how your mind controls your metabolism, and practical tips for optimizing your well-being.

Don't miss this valuable conversation on boosting your health and vitality.

I'm so glad you're here today.

and let the class begin.

♪♪ ♪♪ So, what is metabolic health, then, for people, and how can they optimize this?

>> Yeah.

So, well, first of all, I think you hit the nail on the head.

There is a movement and a tribe of doctors who are sort of waking up and realizing that we are missing the elephant in the room of modern American healthcare.

And the elephant in the room is that, first of all, the vast majority of things that are killing Americans today are conditions based in our dietary and lifestyle choices over the course of our lifetime, which means that we have huge amount of agency in changing our fate in terms of these diseases.

>> How many diseases would you say are caused by food and nutrition alone?

Our diet.

>> 9 of the 10 leading causes of death in the United States are either not only just caused by food and lifestyle but are directly attributable to dysfunctional blood sugar or are worsened by elevated blood sugar.

>> Wow.

Really?

>> 9 of the 10.

>> What's the 10th one?

Well, to go through the ones that we're, like -- what we're talking about, we're looking at things like Alzheimer's dementia, which is now being called, called Type 3 diabetes because it's so related to blood sugar, heart disease, Type 2 diabetes, cancer is very much driven by blood sugar, chronic kidney disease, which is very much a problem of the small vessels in the kidney becoming narrowed in part because of metabolic dysfunction and erratic blood sugar control.

Chronic lower respiratory infections is one of the leading causes of death.

And we know that people with unstable, elevated blood sugar have much higher mortality, even with something like influenza or pneumonia.

Having high blood sugar actually can get into the fluid of the lung and feed the bacteria that leads to some of these issues.

And of course, with COVID, we've known now, since the very beginning of the pandemic, that having metabolic dysfunction, diabetes, is a key accelerator and driver of mortality and morbidity.

There's some odd ones on there, too.

For instance, suicide is actually on the top 10 list of killers in the United States.

And people with diabetes or metabolic dysfunction actually have higher risk of suicidality.

>> Really?

>> So it's all across the board.

And so what's really fascinating is the way in which, these dietary and lifestyle factors are essentially linking so many of the conditions that are killing Americans today.

And the way we've approached it is, we've looked at these as all isolated silos.

We think of them as all different things, like, "Huh.

We wouldn't treat diabetes the same way we treat cancer, or kidney disease the same way we treat Alzheimer's."

But when we look at these through the root-cause approach that you talked about, and sort of the fancy term for this in medicine is systems and network of biology -- what is the network between diseases rather than how are they all different.

When we treat at that level, it's so much more efficient.

And we can actually generate good health in the body as opposed to just reacting to symptoms and managing conditions.

So I think that's what a lot of doctors are waking up to.

They're sick and tired of being reactive, practicing sick care, practicing, you know, this end-of-the-line medicine, and they want to help generate health in people's bodies.

>> Wow.

Interesting.

>> And that's a totally different way of practicing.

>> Right, yeah.

That's inspiring.

And so what I'm hearing you say is, blood-sugar management or control is one of the key factors of either being healthy or potentially linking to one of these other, I guess, diseases.

Is that right?

>> That's right.

Yeah.

And and what it really comes down to, which kind of gets at your question of, "What is metabolism?

", metabolism is fundamentally the way that we make energy in the body.

So we eat food and, you know, food has, you know, fat and glucose in it and either fat or glucose -- glucose is sugar -- can be used to convert into a type of energy that our cells can use, which is called ATP.

So we take in this substrate, but we have to convert it through our mitochondria in our cells to a form of energy we can use, a currency that our body understands and can use.

That process of conversion is metabolism.

And this is happening in every single one of the 37 trillion cells in our body.

And it has to work properly.

>> So break it down for me then.

Fat or glucose, or I guess carbohydrates, enters the body through the foods we're eating, right?

>> Yep.

>> What happens after that?

How is it processed in the body?

Through the cells, through the mitochondria, how is it processed?

>> Yeah.

So, looking at carbohydrates, for instance, they go into our digestive tract, they're broken down and absorbed into the bloodstream, broken down into simple sugars, like glucose and fructose.

These go into the bloodstream, and let's say we're talking about glucose, which is blood sugar.

This signals to the body, particularly in an organ called the pancreas, to release insulin, which is a hormone.

That hormone allows you to take that sugar out of the bloodstream through the cell membrane, into the cell.

Once it's inside the cell, it's broken down even further and then goes into the mitochondria to go through a chemical processing that then creates ATP, which is this molecule that can be then used to essentially power all the millions of cellular processes that are happening every second.

>> So ATP is the power, is the fuel?

>> It's the fuel.

It's the battery in our body.

>> Okay.

And so the way it's processed is, it's based on the foods we eat, whether it be fat or sugar that comes through.

Does that determine how the quality of the energy, or what does that mean within?

Is it all equally the same when it converts to an ATP or...?

>> Well, I think the way to think about it is to really focus on the mitochondria.

This is the energy factory of the cell.

This is the powerhouse of the cell.

And the thing that people really need to understand is that our diet and our lifestyle in the modern Western world -- so past 50 to 100 years -- so much of it is actually damaging the mitochondria of our cell and creating problems in that conversion process.

So for instance, when we eat too much sugar -- okay?

-- and these days, the average American -- >> Is eating a lot of sugar.

>> Like 100 times more than we were like 100 years ago and through the rest of human history.

It's like this massive overload of this substrate.

What that does is, it causes stress on the mitochondria and creates damage.

And one analogy I sometimes use is, imagine you had a factory that was making something like cheese, and, like, all of a sudden, you get like 100 times more of like the raw product, like milk, delivered to the factory.

The workers would be like, "We don't know where to put this.

We can't work."

Like, they go on strike.

There's nowhere to store it.

There's no refrigerators.

It would all go bad.

All of a sudden, you actually produce less cheese even though you have more substrate, you know?

And so it's like we are giving so much of the substrate to the body that it's gumming up the system, it's breaking down the factory, and creating problems.

And the molecular way this is happening is that, each time you have these glucose spikes from eating these refined products or added sugars, your body's releasing more of that insulin.

It's saying, "Okay, more glucose in the bloodstream, so we have to produce more insulin to get it out of the bloodstream.

And over time, the body sees all this insulin circulating, and it's like, "We can't bring more of this into the cell.

There's too much."

And so it actually puts up a block, which is called insulin resistance, which is that cellular process that leads you towards problems like diabetes.

And so what's happening now is the body -- >> And that's why you're storing fat or you're storing other dead cells that you don't need to keep in the body, I guess, right?

>> Right, because insulin is the signal saying, "Tons of glucose around for energy, so we don't need to burn fat for energy."

So insulin is also a block on fat burning.

So it's this chemical signal saying, "Too much glucose around," blocking it from getting into the cell, and also telling the body not to burn fat.

So, of course, for people who are dealing with trouble losing weight, insulin is the hormone we really, really need to be thinking about.

And so we reduce our insulin sensitivity.

Now we have lots of glucose circulating in the bloodstream, but it's not able to efficiently get into the cell.

And then you've got all these other things that can hurt our mitochondria.

And, really, a mitochondria energy-centric view of health can really help us.

Some other things that can hurt the mitochondria are oxidative stress.

So you know, you talked about this a little bit on the podcast with David Perlmutter, but aside from glucose, eating too much fructose -- this comes with sodas or fruit juice or things that have really high concentration of fructose -- it's not going to actually stimulate insulin in the way that glucose does, but what it does is, it goes into the cell, and it's converted into something called uric acid.

And that uric acid creates oxidative stress, which is sort of this sort of damaging reactive molecule in the mitochondria and creates mitochondrial damage.

So now, again, you've got more trouble processing energy through mitochondria.

Environmental toxins are actually a huge problem, as well.

They can directly damage the machinery of the mitochondria.

So we're thinking about things like pesticides and a lot of the fragrances in our personal care products and a lot of the, you know, fragrances and chemicals in our home-care products.

These things actually go into our bodies, damage our mitochondria, make it difficult to produce energy effectively.

Chronic stress can damage our mitochondria through cortisol and through our stress hormones.

So it's interesting to think about how all these different aspects of modern life fundamentally feed down into damaging this precious part of our cell that creates energy.

And when we have -- >> The mitochondria.

>> The mitochondria.

And when we have problems creating energy in our body, this can happen in any cell type.

Again, 37 trillion cells, dozens of organs in the body where this is showing up most prominently in the body is where you're going to see symptoms.

And this is why metabolic dysfunction and blood-sugar dysregulation can look like so many different things.

It can masquerade as so many different symptoms.

And in the conventional system, we see those all as separate.

But when we think about it as this is actually just where a fundamental core problem is showing up in different cell types.

And so if you can address that, you can potentially kind of melt a lot of things away.

So just as some concrete examples, if metabolic dysfunction is showing up in the blood vessels, well, if it's sort of most prominently showing up in the penis, that could look like erectile dysfunction.

If it's happening in the heart, it could look like, you know, heart disease.

If it's happening in the liver, it could look like fatty liver disease.

If it's happening in the ovaries, it could look like polycystic ovarian syndrome, which is the leading cause of infertility in the United States, which is a metabolic problem.

And if it's happening in the brain, it could look like Alzheimer's dementia.

And so it's got all these different faces but fundamentally is rooted in a core dysfunction in how our body is converting food to energy.

And a lot of that has to do with this chronic over nutrition, overloading ourselves with too much to process, gumming up these systems, and then the many other lifestyle factors like toxins, stress, sleep deprivation, and sedentary behavior that can also hurt the mitochondria.

>> Right.

So, blood-sugar management and metabolism management, is that right?

Is that the main things we should be thinking about?

>> Yeah.

>> How does blood sugar and metabolism work together.

>> Yeah.

So, the way that those sort of things link up is that, if your blood sugar is quite erratic, like, let's say it's going up and down in big spikes and valleys... >> Every day, yeah.

You're having lots of sugar.

You're, yeah, eating poorly.

You're stressed.

You're overwhelmed.

>> Yeah.

And the majority of foods on the shelves in our grocery stores now have added sugar -- like well over 60%.

So it's not unusual for an American to be on that blood-sugar roller coaster.

Up, down, up, down, up, down.

And that's called glycemic variability.

And that process of glycemic variability is very damaging to our metabolism through the mechanisms, you know, we spoke about of causing insulin resistance, by stressing the body to make too much insulin over and over.

But those high blood-sugar spikes, in their own right, can cause damage, as well.

When your blood sugar acutely goes really high, like after eating a Pop-Tart or eating a pastry or something like that, or a big bowl of pasta, that spike can lead to inflammation.

It can lead to oxidative stress because of the way that it's overwhelming our systems and creating free radicals.

It can also cause a process called glycation, which is where sugar sticks to things in the body.

And so if you can imagine, if your concentration of blood sugar is really high, it's kind of going to just stick to things more, like your blood vessels and proteins.

And that's not good.

That's like a signal for the body that something's wrong.

And so all of these things kind of coalesce to just creating problems.

So the more that we can minimize our glycemic variability and go from spikes and valleys to more gentle, rolling hills, the better we're going to basically be treating our cells.

And it's not just -- it's not just the sort of, like, cellular optimization we're trying to do.

It's also the way you feel.

I think a lot of us have had that experience where we have a really high-carb meal, a big dessert, and we feel like we kind of have a crash afterwards.

It's like that post-meal crash.

We feel lethargic.

Like, we may need to have another cup of coffee.

Or even feel jittery after it, like a big, high-carb meal.

That's -- We really understand how that works.

The body sees a huge load of glucose from a high-carb meal.

The body then surges out that insulin, overcompensates, soaks up all that glucose, and you crash.

And in that crash state is when we feel fatigue, potentially some anxiety.

And it's when people usually feel cravings.

So by learning -- >> You want more.

>> You want more to bring yourself back up because you've kind of crashed.

>> It's just up and down.

>> Vicious cycle.

And I think the majority of American bodies are on that cycle.

Because you think about what we eat, it's, like, breakfast -- it's cereal, juice, toast, Pop-Tarts, pastries, you know, sweetened coffee beverages.

That's all refined sugar and refined grains.

Then you go to lunch and it's bread, tortillas, wraps, chips, you know, all of that stuff.

And then you go to dinner.

Pasta, potatoes, whatever.

And then it's dessert.

And it's like, if you're not -- if you're just going along the normal American cultural treadmill of what's normal to eat, you're on a glucose roller coaster, and that means that your day might be highly labile, in terms of the energy, mood, performance, cravings.

And so learning just simple ways to balance out that glucose roller coaster can be an amazing life hack and really a superpower for essentially getting your day under better control, making you feel better in the moment.

>> Yes.

>> And, of course, creating the cellular conditions to set you up for long-term longevity and health and prevent that whole downstream insulin-resistance cascade that we know is related to so many causes of death in the United States.

>> So, let's speak to people that are listening and watching who maybe have active lifestyles, they like to work out, so they need energy for working out.

They're driven, they're passionate in their careers or entrepreneurship.

They have a lot of friends and activities they like to go to, so they need energy throughout the day.

How can they get the energy without the glucose roller coaster happening?

What are the best foods to be eating throughout the day?

How many times should we be eating?

And does it really matter -- or, does it really depend on each individual's body type?

>> Mm.

Yeah.

So, I think, for the type of person you're describing, the key concept you want to think about is achieving metabolic flexibility.

>> Okay.

>> So, metabolic flexibility means that we are able to use different forms of energy to make, you know, ATP based on what's available.

And what I mean by that is, if there's sugar around, we can efficiently burn sugar to make ATP, but if there's not, the body's fine.

It's like, "Cool.

We've got fat to use for energy."

The average person is not metabolically flexible, and the reason is because they've been on the glucose roller coaster.

Their body is so used to seeing glucose that those pathways are super active.

And they're constantly on that sort of, like, craving hit.

They want more of it.

They haven't really given -- Because glucose is the preferential fuel the body will use, it's the first thing it's going to grab.

It's kind of like that easier thing to use.

It will never go and burn fat if there's glucose.

It will not burn significant amounts of fat if there's glucose readily available.

So, something that we can do, essentially train our bodies, is to give it opportunities to burn fat.

So this is where you start thinking about things like time-restricted feeding or fasting, or potentially doing a fasted workout where you're actually kind of intentionally keeping your blood-sugar levels in the low normal range, signaling to -- And, of course, the downstream effect of that is going to be insulin will be low, because if you're not having a glucose spike, then insulin will be low.

And that insulin being low takes away that signal to not burn fat.

So now your body's like, "Cool.

Insulin's low, glucose is low.

I'm going to tap into my fat storage."

>> So that's when it starts to burn the fat.

>> Exactly, exactly.

>> So if you work out in the morning without eating, you're more likely to be burning fat.

Is that what I'm hearing you say?

>> That's right.

And there's actually a lot of athletes that are using this type of metabolic science to their advantage.

There's a whole community of endurance athletes now that are doing low-carb training, and the purpose of that is that they don't want to be super dependent on glucose during their event, where they're just like, every half-hour, having to take a GU or a bar or an energy drink or something like that and have these big spikes throughout their event.

Instead, they've actually trained their bodies to use fat during an endurance workout.

And there are literally marathoners now who will run the entire thing fasted because they can so efficiently burn fat.

But that's not -- Those pathways have to be kind of worked and developed to be able to do that, and that's metabolic flexibility.

>> So how do you train metabolic flexibility for yourself?

>> I would say the key thing is to minimize these excessive glucose spikes to give your body an opportunity to be in more in the stable, healthy, low range for more time of the day to keep insulin in a lower and healthy range so that your body knows to burn fat.

One way that you can do this, you know, is, of course, with a continuous glucose monitor, which are becoming popular now, where you see what spikes your glucose, modify it, and try and get to a more stable range, or measure your ketones, which a lot of people are doing now.

And this is a finger-prick device, or there are breath monitors.

You can also check in your urine.

And ketones are a byproduct of fat burning.

So if your ketones are super low or zero, it means you're not burning really any fat.

And if your ketones are higher, like above 0.5 or up into the 1s and 2s, you are proving to yourself that you have gotten to a state where your glucose and insulin are essentially stable enough that you're burning fat for energy.

And so something I like to see if I'm tracking these things is, okay, if I've kept my glucose quite stable and low for a couple days, based on the choices lifestyle, I start to see ketones rising up.

And that, to me, is proof of metabolic flexibility.

And I can test things like, "Okay, if I do the Peloton ride first thing in the morning after not eating, does it increase my ketones later in the day?"

and start to do some experiments like that.

And another thing that people can do is ask their doctor to do a fasting insulin test.

It's not a test that's normally done on a regular yearly panel, but it's a really powerful test because, again, if insulin is quite elevated, it's going to be kind of that block on fat burning.

And if insulin is a low and healthy range, it's a signal that your body's probably likely very insulin sensitive.

You're not far down that insulin-resistance pathway.

I like to see it between about 2 and 6.

And, shockingly, the reference range in a lot of labs will say that, like, anything under 25 is normal.

But that would be very, very, very elevated.

And so you want it to be tight and low to know that you're just giving your body that opportunity to burn fat and to work those different pathways.

>> So many people are talking about fasting or intermittent fasting these days.

Is it different for men and women on the ways to fast in order to burn fat, or is it the same for both?

>> You know, I would say it's different for every single person.

>> Sure.

>> You know, and definitely for different genders.

But it's different day to day.

You know, I think intermittent fasting and time-restricted feeding it can be a stress on the body, you know?

And so I tend to think of it as, you know, we've got a certain capacity within the body to manage different stressors.

And we know that certain stressors can be helpful in building adaptations in the body to help us improve -- so, like, cold exposure, heat exposure, fasting, high-intensity interval training.

But there's also stressors in our life that are maybe somewhat out of our control, like work stress or family stress or things like that.

And we don't want to overload our body.

And so, you know, if a woman is potentially in a part of her cycle, for instance, where her body's also already quite taxed... >> You wouldn't do it then.

>> You wouldn't do it then.

And on a day that I'm -- I don't have as much sleep, on a day that, you know, I might be doing a big podcast or something like that, like today, you know, I'm probably not gonna add, you know -- I'm going to be thinking very deeply about food, though, because you also don't want to be eating a big meal and then crashing -- right?

-- during that time when you have to perform.

So it's more about keeping things -- keeping things really stable and not being highly fluctu-- you know, fluctuating.

So I think about more that way.

I think that fasting is great if you're otherwise very well-resourced with sleep, with resilience, psychological resilience, not putting your body probably under intense physical stress during that time.

I tend to do more like zone 2 workouts, you know, sort of low-intensity during fast so as not to add too much stress.

>> Stress to the body, yeah.

>> And, ultimately, too much stress can lead to breakdown.

And so kind of like bringing those things -- just thinking of everything in a really holistic picture.

>> If you stress the body too much, does the blood sugar go up?

What does that do to blood sugar and metabolism?

>> Yeah.

Stress is -- has a fascinating relation with blood sugar.

So, psychological or physical stress can both cause blood sugar to acutely go up even if you're fasted, even in the absence of any glucose.

>> Really?

>> And the reason for this is that any stress signal to the body will release stress hormones, like cortisol and catecholamines like noradrenaline, epinephrine, things like that.

These signal to the body that there's a threat, and the body has trouble interpreting the difference between a physical or a psychological threat.

And so it's going to produce the same stress hormones.

>> So if there's an event that happens in life -- let's call it something we witness or something we see or something we hear or experience -- we think of a thing that causes a stress hormone to go to the body.

Is that what I'm hearing you say?

>> Yes.

>> There's a thought that we have associated with the event, or the stressful -- or the thing that we think is stressful.

>> Yes.

>> And then that causes a stress hormone to enter the body.

Does it go throughout the entire body?

Does it go to the heart?

What happens?

the blood sugar up?

>> Exactly.

>> We hope you enjoyed this episode and found it valuable.

Stay tuned for more from "The School of Greatness," coming soon on public television.

Again, I'm Lewis Howes, and if no one has told you lately, I want to remind you that you are loved, you are worthy, and you matter.

Now it's time to go out there and do something great.

Continue on the journey of greatness with me.

Please check out my website, lewishowes.com, where you'll find over 1,000 episodes of "The School of Greatness" show as well as tools and resources to support you in living your best life.

>> The online course, Find Your Greatness, is available for $19.

Drawn from the lessons Lewis Howes shares in "The School of Greatness," this interactive course will guide you through a step-by-step process to discover your strengths, connect to your passion and purpose, and help create your own blueprint for greatness.

To order, go to lewishowes.com/tv.

♪♪ ♪♪ ♪♪