When I fast, I don't drink coffee—at least for the first five days. Sometimes, as a treat, on days 5-7 of those longer fasts, I'll drink a black coffee... Truthfully, I think I do it just to break up the boredom. A black coffee has never tasted so good as it does on day 5 of a water-only fast.

You have this corset that is holding you together that is beneath your muscles, and it's called fascia ... It's inside that fascia that all of your organs exist, and that's the place where you don't want to see any fat. Where this fat typically shows up is around the liver, around the kidneys, around the spleen, around the gut. That fat is incredibly associated with metabolic disease.

David [Sinclair] and Charles [Brenner] basically go back and forth about two different molecules, NR and NMN, as precursors for NAD. And again, I would say say no disrespect to them, but that's like rearranging the deck chairs on the Titanic compared to exercise.

The data for the efficacy of NR and NMN as a tool to boost longevity is nonexistent at this point in time ... The interventions testing program at the NIH... unequivocally showed that NR did not work. So, if there are benefits to NR and NMN, we haven't seen them yet. And I would argue that if they do exist, they're not going to be that big. They're certainly not going to be on the order of what we see with exercise.

If the purpose of your fast is caloric restriction and weight loss, I don't see how coffee is breaking that

I think that fasting is just such a powerful tool .... I think of it as one of the most powerful drugs we have in the entire toolbox of medicine.

I just can't get enough of the machinating and arguing about this supplement versus that supplement ... You shouldn't be having those arguments until you have your exercise house in order. You shouldn't be arguing about this nuance of your carnivore diet versus this nuance of your paleo diet versus this nuance of your vegan diet until you can deadlift your body weight for 10 reps.

I try to lift heavy as possible during a fast and I do so every day as a way to stimulate mTOR in the muscle [and prevent muscle loss]

I was kind of joking about this with Andrew Huberman the other day, which was I wish they would just create a rule that says, you're not even allowed to argue on Twitter about a molecule until you're exercising 10 hours a week.

The definition of what breaks a fast is as subjective as the definition of, 'What is sex?'

The overarching principle of nutritional biochemistry is you have to be malleable, you have to be empirical, and you have to assume that, if it [a diet or nutritional approach] doesn't work and you've tried it correctly, that's okay—there's another approach.

I wouldn't put sauna as valuable as exercise ... An hour of exercise, I think, is better for you than an hour of sauna if you're really playing the game of of inches.

Sleep is probably one of the most potent drivers of immune function. Sleep deprivation renders people susceptible to a downtick in immune function.

The narrow conception of happiness that most of us have by default is something we’re tying to defend against all of the other things in life that are threatening to undermine it. The one obvious point is that it’s not a safe play. It’s perpetually under threat. Any joy you can feel, by virtue of it having arisen, based on some causes and conditions, is going to pass away.

Exercise is the single biggest elixir for brain health. And it's amazing how much more powerful it appears to be than nutrition, even sleep. And those things are very important, but exercise is in a league of its own.

The difference in risk between a person whose VO2 max is in the top 2.5% for their age and someone who's in the bottom 25%... It's a 5-fold difference in accruing risk of all-cause mortality.

ApoB, remember, is the concentration of LDL and vLDL particles. And what do they carry? Cholesterol and triglycerides. So, anything that reduces cholesterol and reduces triglycerides is going to reduce ApoB. Triglycerides are generally driven by carbohydrate intake. So, more insulin resistance, more carbohydrate intake, more triglycerides.

If you look at low muscle mass versus high muscle mass, what is the improvement? And it's pretty significant. It's about 3x. So, if you compare low muscle mass people to high muscle mass people as they age, the low muscle mass people have about a 3x hazard ratio, or 200% increase in all-cause mortality.

My framework around nutrition is that there are three big levers you can always be pulling with food: dietary restriction, time restriction, and caloric restriction.

Many of the things you think you want, you'll find you don't want all that much if you pay attention to what it's actually like to gratify those desires

If you're sleeping and you're mouth breathing, it is sending a message to your brain that your energy requirements are significant ... This is a physiological state you don't want to be in when you're trying to rest and recover.

The inability to see the six-pack of abs is really an issue of either too small rectus abdominis muscle group and/or too much subcutaneous fat surrounding the rectus abdominis muscles. No six-pack equals one of those two things or a combination of them.

If you tell me you want to live to be 100, you're going to need to keep your ApoB below 30 mg/dL.

You want ApoB to be as close to the level as it was when you were born. So, we start developing heart disease when we're born. That's just the way it is.

You can absolutely be in ketosis and gain weight. You can absolutely be [a] 'fat burning machine' and still accumulate fat.

Where we are today [April 17th, 2020], it's clear to me that the likelihood that this [COVID-19] is going to kill over a million Americans this year is exceedingly low.

In our practice, we think 40 is the age at which a person should have their first colonoscopy if they have no history of colon cancer. About when I had my first one was 40 or 41.

One thing you discover when you learn to meditate is that negative emotions have a very short half-life

What's the most prevalent cause of death globally? Cardiovascular disease ... If you go to 2019, 18.6 million people died of heart disease. Number two, cancer, 10 million. Nothing is in the zip code of atherosclerosis.

When I get into a sauna, it's hot ... We run it at about 198 degrees Fahrenheit. My typical routine is 15 minutes, and then a cold plunge, and then 20-25 minutes.

That's where we're probably seeing the biggest deficits are these women that show up with no muscle mass eating no protein, doing very little strength training. I mean, to me, that is a recipe for a shorter life, but more importantly, a lower quality of life.

I only care about ApoB ... I care about the causative agent of atherosclerosis. ApoB is the thing that drives atherosclerosis.

Mass cannot be created from nothing, and mass cannot disintegrate into nothing. So, if a fat cell gets larger, there is a net accumulation of fat in that cell relative to how much goes out of it. And the converse is true.

Recent studies indicate that COVID-19's fatality rate is closer to influenza's than expected.

About three years ago, I was becoming more and more interested in this idea of zone 2 training ... The definition of zone 2 is the highest level of output you can produce while keeping lactate below 2 mmol.

With MDMA, my first experience on ecstasy, I had this epiphany that this is what consciousness was like when it was no longer encumbered by my self-concern