 Another crucial one, I'll talk about that more, bones, joints, tendons, all right, that gives us extracellular matrix, the connective tissue that holds all of our cells together. Seafood, good for omega-3 fats. Liver is really crucial. So I'd say liver and egg yolks are the two things you really don't want to miss and then the bones, joints, tendons. A few other things, shellfish will fill in some key nutrients. Starches are really pretty crucial. They're valuable for electrolytes like potassium. They're valuable for fiber. You really need the fiber from starches in order to be of good health and they're also valuable for as a carbohydrate source. Fermented vegetables, really important. They provide beneficial bacteria. I'll talk about that more. Colorful vegetables, but really all vegetables, green leafy vegetables, seaweeds, orange plants like carrots, they're all good for you and you want to get a diversity. Now, in terms of animal foods, what's a very common mistake? People only pick one part of the animal and eat that over and over, you know, so they say, oh, I like ribeye steak. So the only part of the cow I'm ever going to eat is ribeye steak and I'll have that steak over and over again. People tend to like muscle meats. We're in that habit. But in fact, different nutrients appear in different parts of the animal and if we're going to be well nourished, we need to provide all the parts of ourselves to our body. And why is that so crucial? Well, I think it's good to think about our ancestral environment and the necessity of fasting. All right? Now, fasting is something we all do overnight, every night while we sleep. All right? And it's a very natural part of our physiology. But think about the natural environment. Here's a quote from a Jesuit missionary who was among the Indians of Canada in the 1630s and he said, I saw them in their hardships and their labors suffer with cheerfulness. I found myself with them threatened with great suffering. They said to me, we shall be sometimes two days, sometimes three without eating for lack of food. Take courage, Chahine, let thy soul be strong to endure suffering and hardship. Keep thyself from being sad, otherwise thou wilt be sick. See how we do not cease to laugh, although we have little to eat. All right? So it's very common among hunter-gatherers, you might go three days without food. All right? And it's similarly with animals. All right? Animals don't have food available every day. What happens to our bodies when we fast like that? Well, we can actually see this in cells. If you put cells in culture and you starve them for three days, what happens? The cells just shrink in size. All right? So all of these cells, they cannibalize themselves and they shrink in size, but they're still fully functional. So everything the larger cell can do, the smaller cell can do. All right? And that's how we maintain full functionality. Our bodies, after a fast, we're designed to cannibalize ourselves, shrink our bodies, but we retain full functionality. So we can still go out and hunt fight whatever we need to do. And this is very basic to biology. And what's the implication for us? In fact, it's crucial to our health to go through this fasting and feeding cycle, because when we're fasting, cannibalizing, that's actually a very smart process. What happens? Our bodies look around for everything in our bodies that we don't need, like bacteria, viruses, like damaged mitochondria, damaged things. We don't cannibalize the healthy tissue, we cannibalize the unhealthy tissue. If you never fast, you're never clearing up those infections, those damaged materials. All right? And then what happens when you feed, you reconstruct everything and you grow yourself back. All right? And when you feed, what's the point of feeding? You need to give yourself the nutrition, you need to rebuild all that tissue. And if you're, and the mistakes people make in diet, they never fast, so they're never cleaning things up. And then when they feed, they're eating things like those cookies that don't give them the nutrients they need to rebuild whatever they cannibalize. And so they're gradually breaking down their bodies and damaging their health. And the thing people most overlook is this exercise of matrix material. So here are experiments if you take tissues and you rinse them with detergent that washes away all of the cell membranes. And then you rinse them with water so that all of the proteins that were inside the cell and the DNA, it all gets flushed away. What are you left with? Well, it still has the shape of an organ. And in fact, it has so much information, this extracellular scaffolding is so sophisticated that if you put stem cells on it, you can regrow the organ and have a functioning organ. So every stem cell, when it hits the extracellular matrix, it knows, all right, this was extracellular matrix for a nerve cell, I'm going to become a nerve cell. This was extracellular matrix for a blood vessel endothelial cell, I'm going to become an endothelial cell. All right, so there's a lot of information in that extracellular matrix. It has a lot of complex molecules. And it has a very different chemical structure than the rest of your body. And you need to eat that extracellular matrix. And the best sources are basically connective tissue. And so things like these bones, joints, tendons, but people don't eat those nowadays because you need to make soups and stews and you need to cook them for a while for those to become edible. And people don't take the time. Another key aspect of diet, you need to listen to your brain, listen to its desires, follow them. The brain is very closely programmed to like and get pleasure from things that are good for us. All right, when we eat good food, it's a pleasurable process. All right, and we have, for instance, a specific hunger for salt, and animals will go to great length. So here's some elephants who have mined 700 feet into the side of a mountain along a salt lick in order to get salt. And there's very little salt in that park in Africa. And so all of the animals go there even though there are predators waiting to prey on them. But they all brave the predators in order to get the salt because they need it. And similarly, we develop hunger and cravings for whatever our bodies are lacking. My wife used to have an iodine deficiency. Whenever she saw an all-you-can-eat crab restaurant, she wanted to go in and she would eat like 40 crabs and I would be stuffed after 12 crabs. But, you know, she could keep eating because her brain told her, oh, you really need this. And we didn't figure it out that it was an iodine deficiency until later. All right. So what does that mean? It's very important that you put together your food in the most delicious proportions. All right. And so which cuisines do you want to emulate? Well, basically any elite royal cuisine of the past, any fancy cuisine that was created for the richest audience, you know, people for whom money was no object and they just wanted the optimal flavor, you know, like classic French cuisine. And so here are some quotes from Julia Child. The only time to eat diet food is while you're waiting for the steak to cook. Fat gives them flavor. If you're afraid of butter, use cream. And the big life-changing event for her that got her into the diet field was I had my first French meal and I never got over it. It was just marvelous. We had oysters, lovely dry white wine, lovely scalloped potatoes, and with a lovely creamy buttery sauce and roast duck. If you look at her, you know, she wouldn't necessarily look like she's tremendously healthy. You know, she was overweight, but she lived to 93. You know, she was quite a bit healthier than, you know, that was probably at least 15 years ahead of average life expectancy then. All right. And it turns out classic French cooking, just about perfect macronutrient ratios, just about perfect proportions of carbs, fat, and different types of things. All right. So when you're thinking about putting together your food, try to make your food delicious. All right. And now one thing I'd like to do is look at obituaries from centenarians and super centenarians. And what's the most common thing you find about diet? It's that they love to cook. All right. The best thing you can do to make yourself live a long time is to learn to cook and learn to enjoy cooking. And why is that? If you're cooking for yourself, you're working with natural whole foods, plants, and animals. And when you cook for yourself, you want to make things delicious. All right. And so you're going to follow those innate brain preferences toward the right proportions, the right mix of foods. So if you're cooking for yourself and you're good at it, then you're almost automatically going to generate a very healthy diet. All right. So that's my quick summary of the optimal way to eat. Now, let me go on to the second area, lifestyle. All right. Now it turns out when you look at centenarians, super centenarians, lifestyle is just as important as diet in extending lifespan. And so if you've read Dan Butler in his Blue Zones books, all right, he goes around the world looking for places where people live a long time. And they don't find a lot of consistency in their diets. All right. So it's hard to find some dietary thing that makes these places stand out. But what does make them stand out? Well, there's a lot of islands. All right. And there's a lot of remote places. All right. A lot of places that got civilization late. They didn't get electricity. They didn't get automobiles. And so what do people do? They're also often in warm places like the Mediterranean, all right, where people don't need air conditioning or heat, get a lot of sunshine. Okay. So these people, they're living very natural lives. They're living outdoors, they're walking lots of places. It's expensive to import food. So they're eating locally grown foods and fish, a lot of seafood. They get a lot of exercise. It's dark at night. They get a lot of social interactions with their neighbors. So it's a very non-industrial lifestyle. And what is the optimal lifestyle? Well, it's very similar to that. It's also very similar to the lifestyle of an animal. All right. So how does an animal live? Well, it gets up in the morning, it goes outdoors. But it was already outdoors, so it hasn't gotten anywhere. But it does find its friends, it interacts with them. It at some point decides it wants to go to the gym and fetch some food. Now the gym happens to be its cafeteria. So it has to get some exercise in order to get its food. When it catches its lunch, it eats it. When it's done eating, grooming, exercising, then it relaxes with its family, with loved ones. And then it gets a good night's sleep. All right. So this is the essence of the healthy lifestyle. And we need all of these elements in our lives each day in order to be completely healthy. Now all six of these things share a common feature. They entrain circadian rhythms. All right. Circadian means on a 24-hour cycle like the sun, the day-night cycle. And all of these things are meant to be rhythmic parts of our lives. All right. And all right. So what happens? Our body has lots of clocks. Every cell has a circadian clock, its own internal clock. We have a trillion cells in our body. All of those trillion clocks need to be synchronized in order for us to have good health. All right. So we have to make sure each of those cellular clocks is working. All right. It's not like the grandfather clock that stopped ticking. And then we have to make sure they're all keeping the same time. Right. It's like in the spy movies. All the spies have to get together, synchronize their watches. If they're going to work together successfully. If our cells are going to work together successfully, they have to synchronize all of their clocks. And if you achieve that, then you'll gain at least six years of life expectancy. All right. So that's a really big gain. What happens if you fail to do it? Well, we have all these different ways of doing it. And it turns out just screwing up any one of them is pretty terrible. All right. So if you look at people who get sleep loss, either because they do night shift work, or they have sleep apnea, which obstructs their breathing and wakes them in the middle of the night, here's the list of diseases they get. And they lose about six years off their lifespan. All right. But totally different way of entraining circadian rhythms is exercise. All right. That's something we need to do in the daytime. And it establishes good circadian rhythms. And what about people who never exercise? What happens to them?