← The Human Upgrade: Biohacking for Longevity & Performance
The Human Upgrade: Biohacking for Longevity & Performance
What If You Stop Eating For 72 Hours? : 1375
00:12:08
Loading summary
Transcript10 lines
- [00:01]
Dave Asprey
Giving gifts to loved ones is really good for your Biology studies show generosity improves mood, reduces anxiety, and increases your levels of feel good neurotransmitters like oxytocin. You can make meaningful gifting a breeze this year with my 2025 holiday gift guide. It's not just for biohackers, it's for anyone on your list who wants to look good, feel good and perform better. Real science backs every product on the list. I've tried and tested each one and they deliver real notice results. The holidays are coming fast. Don't risk giving another gift that ends up in a drawer or worse, in the trash. Go to daveasprey.com giftguide to explore the full guide. You'll find something cool for everyone on your list. That's daveasprey.com giftguide Happy Holidays and Happy giving.
- [00:56]
VRBO Representative
With savings over $390 this shopping season, VRBO helps you swap gift wrap time for quality time with those you love.
- [01:05]
From snow on the roof to sand between your toes, we have all the vacation rental options covered. Go to VRBO now and book a last minute week long stay. Save over $390 this holiday season and book your next vacation rental home on VRBO. Average savings $396 select homes only I.
- [01:26]
Dave Asprey
Fasted for three days and here's what happened. I actually starved to death. You probably tried a 16 hour fast. You skip breakfast. You feel good about yourself. Repeat. It's not that hard. It drops your insulin a little bit, burns some stored sugar. But that's exactly the problem. At 16 hours, you're mostly still burning sugar. Your body hasn't flipped the real switch into deep fat burning yet. It's only after 24 hours, 36, 48, even 72 hours without food that the real transformation begins. Because in three days without food, your body can do what no supplement, no diet and no workout plan can achieve. It can turn back your biological clock. Your body has an anti aging switch and a three day fast is one of the best ways to turn it on. But if you do it wrong or you do it too often, you can damage yourself in a couple minutes. I'll tell you exactly how to do a fast and how often. But first you need to understand that none of this matters if you don't know the one thing that's secretly destroying your body right now. The problem starts with how people think about aging. Most of us think wrinkles, fatigue and brain fog past 30, just things that happen. You get older, you get weaker and there's nothing you can do about it. Doctors don't question it either. They measure the number of birthdays you've had instead of the actual condition of your cells. And because of that, decline becomes the default diagnosis. So what do you do? You might reach for creams and treatments, hoping they'll somehow make you younger and feel better. And yeah, they can give you a surface level boost. Some of them actually work. You'll get smoother skin. But those things rarely reach where aging actually begins. Aging doesn't start in your skin. It starts inside your cells. Your cells run on tiny little batteries or engines called mitochondria. They turn food and oxygen into energy. But the problem is, modern life is really hard on mitochondria. Stress keeps your cortisol high all day, and it breaks down your repair systems. And bad sleep means your cells don't get a chance to repair DNA. And if you're eating constantly, having snacks all the time, late night meals, it keeps your insulin high all the time. And when insulin stays high, your body can't switch from storing mode to repair mode. So damaged parts of your metabolism build up. Broken mitochondria stay broken. Inflammation spreads to your brain, your organs, your immune system attacks the wrong things, and it misses real threats. Even healthy eaters feel it. You're working harder, but you're getting less energy. You feel tired all the time. Your brain fog is just unending. And you look older than you should. And that's because your cells are stuck. They can't repair themselves. When you never stop eating, the damage keeps stacking up faster than your body can clean it out. And that's the real cause of what causes aging, inside and outside. So you need to give your body a break from food and let it repair itself. We're talking about a deep metabolic pause to restart repair. Not another pill, not another diet trend, but an actual break, long enough for your body to flip the switch back on. When you do this, your cells activate a process called autophagy, which is when your built in repair switch turns on. Insulin goes down, inflammation goes down, growth hormone goes up to preserve your muscle, and it can repair your tissues. Your mitochondria even start rebuilding. The enzymes that repair your DNA start working again. And in just a few days, the brain fog lifts, gets your energy back, and the engines inside your cells start running like they're supposed to. But most people won't actually experience those benefits with a standard 16 hour fast. And that's because of one common mistake. When you stop eating, your body doesn't just shut down, it moves through multiple Fuel phases. In the first few hours after a meal, you're in the fed state. Your body is busy breaking down food, sending sugar from the meal into your bloodstream and using insulin to move that sugar into cells for quick energy or to store it as glycogen in your liver and in your muscles. You're basically running on the fuel you just ate. Around three to four hours in, you shift to the early fasting state. Blood sugar and insulin levels drop because there's no new food coming in. And your body starts burning the glycogen that your liver stores and turns that into glucose, which keeps your brain and muscles powered. And as those stores of glycogen go down, your body starts looking for a backup plan and slowly begins to break down fat, releasing fatty acids into your bloodstream. And that's where a little bit of fat burning begins. Because by about 18 hours without food, most of your liver glycogen is gone. And that's when your metabolism starts to pivot into a fasting state. The 18 hour mark is when you actually do burn more fat. And your liver turns those fats into ketones, which is a really good fuel for your brain. And your brain loves ketones. That's the moment people talk about when they say fasting flips the fat burning switch. But here's the problem. Fat burning doesn't kick in until after your glycogen levels have dropped. And that's why ending a fast after 16 hours is better than not fasting for 16 hours, but it does cut the process two hours short. You've just started dipping into fat free energy, but you haven't stayed long enough to get the full benefits of it. So if your goal is to maximize fat loss or metabolic benefits, breaking your fast too soon means you step out right as the good stuff is just starting. So let me walk you through what happens to your body when you fast for three days in a row. And if that sounds like an enormous lift, it's not as hard as it sounds. Like we just talked about, the first day of a fast is all about burning through the easy fuel. Your body has stored away sugar. Your liver empties its glycogen tank, your muscles empty their glycogen tanks, your insulin levels drop, and your body starts tapping into fat. And that's also the roughest day. Your hunger signals are loud, your mood can swing, you get hypoglybitschy, you get hangry, and you're probably a little bit tired and foggy unless you artificially boost your ketones which makes it painless. You can do this by putting butter and MCT in your danger coffee. Or you can use something called kinetic, which is a ketone drink. Use code Dave at Kinetic ketones are like a premium fuel for your brain. And many people notice their energy stabilizes and their minds get sharper when they're in ketosis. Can happen through the things I just mentioned, or it can happen just by naturally waiting. But if you don't want a day of feeling hangry, that's a hack. Butter, an MCT in your danger coffee or a ketone supplement. But behind the scenes, something important is happening. Your hormones are shifting, growth hormone rises to protect your muscles, and your metabolism begins preparing for a deeper reset. And by the second day, your sugar tank is fully empty and your body makes a powerful shift. It's going to run mostly on fat and ketones and possibly some muscle if you're not doing something to preserve your muscle. Ketones are like premium fuel for your brain. And many people notice their energy stabilizes and their mind sharpens when they're using ketones as fuel. And deep inside your cells, autophagy kicks into high gear. When you do this, inflammation starts to fall, your body starts to break down old, weak immune cells, and it makes room for fresh new ones. You might have felt deprived on the first day, but now on the second day, you strangely feel calm and clear. And by the third day, the magic peaks. Ketones are at their highest and your brain feels completely steady and focused. And more energy goes into your brain than normally does because your body's not worried about digesting food. Stem cells start to wake up and it lays the foundation for a stronger immune system. Once you do start eating again, your mitochondria, they become more efficient, more effective at making the fuel of life. And in your brain, ketones help spark BDNF release, which is a growth factor that sharpens your memory. Oh, and ketones are anti inflammatory too. So to put it simply, this is when fasting shifts from just burning fat to actually upgrading your biology. You feel lighter, clearer, and more in control than you have for years. And you are not obsessed with food. You don't even think about it. So 16 hours without food, it burns sugar. 72 hours without food turns on your body's full longevity anti aging switches. A three day fast reverses aging, sharpens your brain, and it activates stem cells. And it's not even in the same category as a standard intermittent fast. But even a three day fast is useless if you're doing it the wrong way. In fact, if you follow the wrong process, your body can start burning muscle instead of fat and a careless fast can do more harm than good. If you skip electrolytes, things like sodium, potassium, magnesium, it can give you headaches, dizziness, heart palpitations and cramps. You don't want that.
- [09:50]
Your brain is probably underperforming right now. No judgment. Most brains are. In fact, you're probably not thinking as clearly, sleeping as deeply, or performing as.
- [09:59]
Well as you could be.
- [10:00]
Braintap helps you unlock your full potential. It offers More than 2000 in app audio sessions and an innovative headset that together deliver light pulses, binaural beats, isochronic tones, guided visualizations and 10 cycle holographic music to rewire your brain for higher performance. In just 20 minutes you can achieve deep brainwave states that would take hours through traditional meditation. It also helps regulate your sleep wake cycle, making it easier to fall asleep, stay asleep and wake up refreshed without drugs or dependency. This isn't just some trend. Braintap leads with tons of real science. They've conducted multiple studies proving this works. From enhancing memory and focus to accelerating cognitive learning, managing stress and deepening visualization, Braintap is a holistic tool for peak performance in work, creativity and daily Life. Go to BrainTap.com Dave to get $100 off the BrainTap Power Bundle.
- [10:59]
American Giant Representative
With the state of today's economy, it's more important than ever to invest in products that last for years to come. As the seasons shift and get cooler, make sure your closet is stocked with durable layers that stand the test of time. From American Giant American Giant's clothes work harder and are wearable season after season. Their greatest hoodie ever made is made from the highest quality materials that are cut and sewn right here in the United States. So you're investing right back in your local community. Choosing American Giant means taking a stand for American manufacturing and hard working Americans. Something other mega corporations don't care about. From fleece to knit, all in a range of colors for versatile daily wear, American Giant delivers everyday pieces designed for everyday life. Feel the difference of quality Made to Last Clothes from American Giant Get 20% off your first order with code STAPLE20@ameran-giant.com that's 20% off your first order at american-giant.com with code STAPLE20.
- [12:00]
Dave Asprey
If you push yourself to train hard when your glycogen is low, your body is going to break down muscle tissue for fuel, which means you can end up skinny, fat and looking weird and and it doesn't feel good to work out during a long fast. And it's more stress than your body needs. So if you end your fast recklessly by binging on pizza, sugar, junk food and alcohol, it is a shock to your digestive system that spikes your insulin beyond belief, creates the inflammation you just spent three days clearing up. You could add in some bad sleep, some unmanaged stress to the mix. Your cortisol rises and that suppresses the autophagy that you want wanted to have, and it accelerates aging instead of slowing it. So a sloppy fast can actually push your biology backwards and that leaves you more depleted than when you started. So you can prepare your body ahead of time. You can support it with minerals during your fast. Keep your activity restorative rather than strenuous. And you can break your fast with a little bit of wisdom and knowledge. And you get that regenerative power without the damage. So preparation begins the day before you fast. You cut back on carbs, remove alcohol, hydrate deeply, make sure you have enough minerals in the system. I like Minerals 101 from Sup Grade Labs. It's one I formulated. You want to have lots of minerals when you're fasting. And once the day begins, stay consistent with two or three liters of water a day, always with electrolytes or at least some high quality salt. Choose light activities like walking, gentle yoga, or if you feel up for it, sauna. Instead of this high intensity exercise, get some extra sleep, make it a priority, make it dark before you go to bed and when you're asleep. And take some magnesium at night along with those electrolytes so you have better recovery. And when it comes time to refeed, start small bone broth, gently cooked protein, eggs, wild salmon, grass fed beef and some cooked vegetables. The following days are about bringing your body back into a higher level performance mode. Pay attention to your energy, your mood, your digestion, and avoid the temptation to eat tons of junk food. Just bring back in the normal healthy foods that you like. And remember a three day fast is powerful enough that you should only repeat it a few times a year, maybe once a quarter. Give your body time to rebuild stronger between resets. Just because a three day fast is beneficial doesn't mean that doing it once or twice a month is going to be beneficial. Your body needs cycles, it doesn't need constant stress, it doesn't need constant comfort. And most importantly, throughout your fast, monitor how you feel by paying attention to your energy, your heart rate variability and your mood. And pay attention to how you feel because your body is a miracle, and everyone's biology is unique. Some people feel a rush of energy on day two, others feel calm and centered, and some people just feel weak and restless. And none of those responses is wrong. They're signals. Your body's speaking in its own language, and it shows you where it's healing, what it's having trouble with, and how it's adapting. And I know this because I've taught 100,000 people how to fast with my Fasting challenge and wrote two New York Times books about fasting. And it's changed my life dramatically. So I'm not just saying these things. I have studied these things. I have lived these things. And I've taught lots of people how to do it. It really does work. And we spend our whole lives adding things. Supplements, routines, superfoods. And sometimes the most powerful thing you can do is just subtract you remove food for 72 hours and watch your body remember what Mother Nature designed it to do. Heal. Rebuild. Regenerate. And the answer isn't out there. It's already inside you. You just have to get out of the way and let it.
- [15:46]
Podcast Disclaimer Narrator
A human Upgrade Formerly, Bulletproof Radio was created and is hosted by Dave Asprey. The information contained in this podcast is provided for informational purposes only and is not intended for the purposes of diagnosing, treating, curing, or preventing any disease. Before using any products referenced on the podcast, consult with your healthcare provider carefully, read all labels and heed all directions and cautions that accompany the products. Information found or received through the podcast should not be used in place of a consultation or advice from a healthcare provider. If you suspect you have a medical problem or should you have any healthcare questions, please promptly call or see your healthcare provider. This podcast, including Dave Asprey and the producers, disclaim responsibility for any possible adverse effects from the use of information contained herein. Opinions of guests are their own and this podcast does not endorse or accept responsibility for statements made by guests. This podcast does not make any representations or warranties about guest qualifications or credibility. This podcast may contain paid endorsements and advertisements for products or services. Individuals on this podcast may have a direct or indirect financial interest in products or services referred to herein. This podcast is owned by Bulletproof Media.