BenGreenfield-PerfectHealthDiet.mp3

Hey, folks, it's Ben Greenfield here. And one of the more popular episodes that we ever had@BenGreenfieldFitness.com was when we had Paul Geminet on to talk about the Perfect Health Diet, which in my opinion is one of the better diets out there when it comes to really aligning very, very well with the biochemistry of the human body. Now, Paul is an astro. Was an astrophysicist at the Harvard Smithsonian center for Astrophysics, and he had a chronic illness that led him and his wife to develop a lot of the views of diet and health and disease and kind of fixing the body and supporting the body through proper dietary intake that you're going to find in the book the Perfect Health Diet. Now, what I would caution those of you who are listening in to do, if you'd like, is go back and listen to the first podcast that I did with Paul when he first came out with the Perfect Health Diet. But now what Paul has done is released a second edition of the book. I read it a few weeks ago and cover to cover, didn't put it down, so I was finished. It's a fantastic read. And Paul and I are going to dig into some of the nitty gritty details of this book today and kind of walk you through the Perfect Health Diet and what it means for you and how it can help you. So, Paul, thank you so much for coming onto the Ben Greenfield fitness podcast again.

Oh, Ben, it's great to be with you.

And I guess a good place to start here is this is a second edition. Why release a second edition? Aside from the fact that it's hardcover now, which is very cool.

Well, we've really learned a lot in the last two years. So at about the time we released the first edition, that was also the same time that we started blogging. And our only real experience applying the diet was in ourselves, my wife and I. And since then, probably at least 20,000, 30,000 people have adopted the diet. We've had thousands of reader reports come back. We've had hundreds of chronic diseases get cured. And at the same time, I've been doing probably three blog posts a week for most of those two years. And we've learned a lot. So it was about ready. We had learned how to improve the advice. Some of the advice in the original edition wasn't quite right. And so we were about ready to figure out how to go through everything one more time, just refine it, try to make it really as perfect as we could. And it just happened that Scribner came and approached us and asked if they could publish a new edition. And that worked out really well because I've been getting approached by foreign publishers asking about the rights and. And I didn't really know that much about how to run a publishing business. So I thought it would be a good deal to have Scrivener come out with a very professional version.

Yeah. And it looks great. It's a good book to read or a fun book to read. I always like the hardcover stuff. Even though I read half my books on the Kindle, it's still nice to get the hardcover copy. So anyways, even though I mentioned that people can go back and listen to the first podcast that I did with you to kind of hear your background and your story, which I would encourage people to do. Can you, as a way of introducing people to what the Perfect Health Diet actually involves, walk people through what a sample day of eating actually looks like on Perfect Health Diet? Or what I know you abbreviate in the book as the PhD.

Yeah, well, maybe the easiest way to illustrate is just to say what I do typically, which is I do intermittent fasting almost every day. So I extend the overnight fast to about 16 hours and I eat two big meals within an eight hour window. Typically for me, I don't eat anything until midday. So around about noon I'll go out running and when I get back from that, I'll have lunch and that's my first meal. And it's usually we have some very large bowls and I'll put in rice or potatoes. I'll usually put in some eggs, some vegetables, some leftover meat, coconut milk, some rice vinegar, things like that, and mix it all up, warm it up in the microwave and have that for lunch. And then dinner is the one time that we cook. And we'll have a meat and we'll have a starch and we'll have a vegetable and a glass of wine. So that's a typical day. And if you go to our website, perfecthealthdiet.com, there's a page that describes the diet. And we have our own Perfect Health diet food plate, which is in the form of an apple with a yin yang symbol inscribed in the apple. And the body of the apple shows the design of a meal. And the leaf and stem are pleasure foods like chocolate and fruit and nuts and things like that. And so the yin yang symbol signifies a balance between plant and animal foods. And so we started out, this started out as kind of a paleo diet, and we had good and bad Health effects on a low carb paleo diet. And we just started studying the literature and refining the diet and just kept migrating and eventually got closer and closer to traditional gourmet cuisines. So our food is extremely tasty and delicious, and it's a whole food, natural whole foods diet. And it is paleo in the sense that it excludes most modern agricultural foods. So think of it as sort of a paleo implementation of gourmet French or Dai or Chinese cuisine. Yeah.

And I would say for the listeners who are listening in the. The way that I'm eating now is very much influenced by the perfect health diet. Probably a few of the things that I do is about five days a week or so I eat even a lower carbohydrate intake in terms of not including some of the fruit and starchy vegetables and rice that is in the diet to keep myself a little bit more fat adapted, so to speak, for some of the endurance racing that I do. And then I also tend to throw in a little bit more of like the engineered meal replacement stuff, like super greens and stuff that I need just because of the number of calories that I'm burning during the day with my training. But the actual basis of my personal diet is very, very much influenced by this book, my previous discussion with Paul, and also his current fleshing out of the details of the perfect health diet. And, you know, one of the really important things that you get into, Paul, is optimal macronutrient ratios, ratios of carbohydrate and fat and protein. And the way that you go about describing what the optimal macronutrient ratio is for humans is you say that compared to apes and other mammals, we humans have lost our guts. What do you mean when you say that we've lost our guts?

Well, that's a really important point. You know, it's very interesting. You know, both my wife and I are scientists. And, you know, one of the things that naturally occurred to us when we're thinking about, you know, what's the right strategy for figuring out the optimal human diet? Well, if you have the right strategy for figuring out the optimal human diet, it should work for animals, too. You should be able to go to a cow and say, what's the optimal cow diet? And to a cat and say, what's the optimal cat diet? And, you know, the same biology that determines that ought to work in every case. And what we realized was that all of these animals have essentially identical nutrient needs. And the reason is because their cells have the same structure. You know, they're lipid cell membranes containing proteins and water and electrolytes, things like that. And so since every animal has the same nutrient needs, it's a little surprising at first that they have very different diets. But it turns out what evolves in animals is the digestive tract. So every animal has a different digestive tract. And the design of the digestive tract has the purpose of transforming different diets, different foods, into the mix of nutrients that an animal needs. So a cow has all these, has rumens and foregut, digestive apparatus to convert plant foods into fats so that it ends up delivering a high fat diet to its body. Whereas an animal like a cat or a tiger that's already eating an animal based fairly high fat diet doesn't need to have any of that machinery. Instead, it has a sizable liver for converting protein, manufacturing glucose from protein and things like that. So every animal is a little bit different. It turns out when you compare the size of the digestive tract to the size of the body, humans have an extremely small digestive tract. Animals in general have much bigger bellies than we do. The reason is we're basically accustomed to eating a diet that's very close to the mix of nutrients that we need. So at least in the Paleolithic when we were hunter gatherers and were gathering both plants and animal food, we would end up getting just about the right mix. Now, unfortunately, things have changed and people get a quite different mix because what's cheap to produce with agriculture is different than what was available in the Paleolithic. So the main significance of the fact that we've lost our guts, we don't have that much digestive tract machinery, is that if we really want to be healthy, then it really pays us to eat a diet that's pretty similar to our optimal diet and that's not far removed from breast milk. So you might have noticed that the composition of breast milk is the same in every mammalian species, at least very similar. And the reason for that is that babies tend to have immature digestive systems. So the mother can't afford to provide a milk that needs a lot of transformation in the digestive tract. So they all come very close to that universal set of nutrients that mammals need to be healthy.

Gotcha. So what this comes down to is that if you look at, say like a gorilla, they can take all that vegetable matter that they eat and convert that into fatty acids because their gut is so big and humans just can't. We don't have the capability to do that. The 30 banana a day type of diet doesn't work so well for humans when it comes to, like, the macronutrient ratio is what it comes down to.

Yeah, that's exactly right. So, yeah, the gorilla diet is basically 60% fiber that gets, you know, 60% of their calories come from fiber that gets converted by bacteria to short chain fatty acids. Whereas humans, the most we can, we're physiologically capable of getting from fiber is about 6% of energy. And, you know, most populations are around 1%. So, you know, we're just not designed to eat anything like the kind of diet that gorillas and chimpanzees can eat.

Right, yeah, it makes sense. Now as you go on and you talk about macronutrients in the book, after you lay down kind of the basis for how a perfect human diet would really actually be close in terms of carbs and protein and fat to breast milk. And I know that you don't actually condone drinking your breast milk in the book, at least for people other than babies, you launch into protein. And you specifically have an interesting discussion in the book where you, where you talk about the toxicity range for protein. Now we have a lot of listeners who are athletes beating up their bodies and they're trying to hit certain protein ranges for muscle repair and recovery. So for those folks, what is the toxicity range for the amount of protein that they should take in on a daily basis? And how did you arrive at that value?

Yeah, well, every nutrient has a range of healthy consumption. And every nutrient, there's an amount that is too much. And so for protein, what happens with protein is we have no storage reservoir in our body for protein. So all the protein you eat is either utilized to make our proteins within tissue or it's burned for energy. And when it's burned for energy, it releases nitrogen molecules which form ammonia. And ammonia is toxic. Ammonia is removed through conversion and to. Uric acid. And the name escapes me. Urea. And, you know, so the urea goes out in the urine and anyhow, but we have a limit on how much nitrogen, how much ammonia we can dispose of that way. And so basically, you successfully eliminate all of the nitrogen without toxicity when you're eating about 600 calories a day of protein, which is about the amount in a pound and a half of meat. And from that point on, the more protein that you eat, you start generating a little bit more ammonia that your body isn't really good at disposing of. And that can lead to various problems, including kidney stones or gout or other issues. There's also Issues with the gut bacteria. If you eat too much protein, the digestive tract doesn't absorb it as much. And so you leave more protein for gut bacteria. And that tends not to be such a healthy thing. So you don't really want to eat in excess. Generally speaking, if you eat 600 calories a day of protein, that'll be enough for just about any athlete. From that point, the benefit, you should focus more on carbohydrates as a way to promote muscle recovery.

Gotcha. So basically it looks like in the book that you say that the body's ability to convert ammonia to urea peaks with a protein intake of 230 grams per day. But the levels of ammonia become significant at a much lower calorie range than that. So basically it comes out to about 30% of the daily dietary intake being protein.

Yeah, right. So it's fairly safe to get up to around 30%. And it starts to get, you know, by the time your protein intake is over 40%, then you're basically running out of the ability to dispose of the protein safely. And so every additional bit of protein that you get is poisoning you.

Right, right. That makes sense. I know a lot of folks tend to exceed those values, but we'll get into your discussion on f fat here in a second because I know that as it probably comes to no surprise to people, since I'm adhering to a lot of your dietary concepts, you do encourage fat consumption. But before we talk about a little bit, a little bit about fat, I want to touch on carbohydrates and glucose. So you talk a little bit about glucose needs and specifically how some of what we need for our daily carbohydrate for our daily glucose, in terms of what our brain and our kidneys and whatnot needs, part of that can be supplied by the conversion of ketone bodies into glucose. Now how exactly does that happen, the conversion of ketone bodies into glucose? And kind of my follow up question to that would be based off of the fact that we can convert some fats into glucose. What would our recommended carbohydrate intake be for the average person who's going to be following the perfect health diet?

Diet. All right, well, it is possible to convert some ketones into glucose if you supply a donor source of carbon like citric acid, say from lemon juice. But it's not really a major pathway in the body for most people. But ketones can substitute for glucose, so the brain and neurons can utilize ketones instead of glucose. So your glucose utilization goes down. So when you're making ketones, you don't need as much glucose. And so that's the major reason why ketones help you do okay on a lower carb diet. So basically people, if you're not producing many ketones, then the optimal carbohydrate intake is probably around 25 to 30% for adults of energy. And for very young children it's higher, it's more like 40%. So that's why your young children will tend to have a sweet tooth, carbohydrate tooth. And you can, if you reduce your carbohydrate intake well below 25 or 30%, then it's a good idea to support production of ketones by eating a lot of coconut milk or MCT oil, things like that, that make it easier for your liver to produce ketones. So you don't want your brain or your nerves to feel like they don't have enough energy. So if you're going to, if you're going to cut down carbohydrates very far, then it's good to help your body manufacture some ketones. So the best way to do that are short chain fats like in coconut milk. And if you give yourself a little bit of branch chain amino acids, that helps support it too.

Yeah, because those branched chain amino acids can be converted into, into ketone bodies as well, right?

Yeah, that's right. So leucine goes entirely to ketones when burning that for energy. And branch chain amino acids also help support the metabolism of ketones generally. So any ketogenic diet will be a little healthier if you have a few extra branch chain amino acids around.

Now, for those of us who are out there running and who are athletes, you know, you talk about the body's basic natural glucose needs in the book, like the minimum amount of glucose that's necessary. And I think a lot of people kind of make a mistake, like with a low carbohydrate diet in terms of undercutting even what is naturally required by the body. Now, part of this is related to joint pain and joint injury. Can you talk a little bit about how getting adequate glucose could potentially help your joints?

Yeah, well, that's important because, you know, roughly, roughly speaking, close to half the protein in your body exists outside of cells. And you know, Collagen is like 30% of the protein in your body, and that's all outside of cells. And you know, this material is basically the, it's called the extracellular matrix and it's basically a scaffolding for your body that cells Fit in. And when I give talks and when I talk about this, I show some slides where people are working on how to make artificial tissues for transplantation, like how to construct a new liver. And the problem with organ transplants is they get rejected because the cells inspire an immune attack, because they're recognized as foreign. And what they're experimenting with is they take a liver and they use detergent to pull away all of the cells. So they dissolve the cell membranes and then the cells just wash away and you're left with this extracellular matrix. And then they put in some of the sick person's own stem cells, and the stem cells will build up a whole liver and blood vessel network and so on. Because the extracellular matrix has the scaffold, it tells the cells where to go, what kind of cells to put where. And they've actually made organs like this and transplanted them into mice. And they work for a few weeks maybe, you know, so it's not ready to go in reality. But you can actually look at these organs with, you know, the cells removed and see the structure. And so the extracellular matrix is extremely important. And that's composed of a mix of protein and carbohydrate connected with some sulfur sulfate based side chains. And so that's the structure of collagen and the proteins in there. And then you have some lubricants like hyaluronic acid, which is mostly composed of glucose. And your body is constantly producing this in order to lubricate the joints. The joint tissue is mainly composed of the extracellular matrix, which is a large fraction of it, is made of sugars, carbohydrates, and then all the lubricant in the fluids is composed to a great extent of carbohydrates. What happens is, if your body is really starved of carbohydrate, then it gives priority to the brain. So your brain gets as much as it needs and everything else kind of shuts down. So you shut down producing this joint lubrication. You shut down a lot of wound healing. So if you wear down the joint tissue, you don't replace it as readily. And so for someone like an endurance athlete, you don't want to be starved, totally starved of glucose, because you won't repair these joint injuries. And, you know, it may not have any immediate effects, but after 20 or 30 years of running, I doubt it would be good for you. So you sort of, you know, you definitely want to at least a few days a week, supply yourself with plenty of glucose. You know, either eat a Steady amount around what we call the natural carb intake that meets your body's needs. Or else if you want to introduce some intermittency, have some low carb days, but have some higher carb days as well.

Right, so you're kind of reloading those carbohydrate levels. And based off of this, in terms of the average daily carbohydrate, we talked about protein being about 30, 30% in your perfect health diet on an average day. About what percentage of the diet is comprised of carbohydrate?

Well, I would say for a typical person, not an athlete, I would recommend around 30% carbs, around 15% protein is typical, and about 55% that.

Now, weren't we just talking about 30% protein as being, or is that where you top out in terms of toxicity?

Yeah, so 30% protein is safe. So I would say a safe range for protein is 10% to 30%. But I think only athletes, especially strength athletes, would want to be at 30% protein. Most people, 15 to 20% is great.

Gotcha. Okay, so you also, when talking about the problem with cutting carbohydrates too low, with getting down, you know, some people are getting, you know, in the range of like 30, 40 grams a day, and sometimes less. You say that a low carb diet could also increase the risk of hyperglycemia, which seems to kind of be counterintuitive. How exactly could a low carb diet increase the risk of hyperglycemia?

Yeah, well, what happens is the body has very sophisticated mechanisms. So, you know, in the Paleolithic, we couldn't guarantee getting food all the time. We couldn't guarantee what kinds of food we'd come across. And so the body has mechanisms to cope, at least for a short time, with extreme diets. And when you're on a very low carb diet, it basically channels the glucose to the brain and the nerves, which are the most important critical organs that have to function well all the time in order for you to survive. Whereas other things like repairing the extracellular matrix somewhere, you can get by putting that off for a week or two. So, you know, so the body just shuts down certain uses of glucose and directs things elsewhere. And when it shuts down all the other parts of the body from using glucose, we call that insulin resistance. You know, so basically, even if you give insulin, they won't take it up because they're under the impression that the brain needs it. And so what happens is, if you eat, if you're starving yourself of carbohydrates, and then you eat a large amount of carbohydrates, then it will take, there'll be a lag before your tissues figure out, oh, we don't need to be conserving glucose anymore. And so the initial rise in blood glucose will be higher because you have fewer tissues taking it out. And then the other phenomenon that can happen is after fasting you can actually get elevated blood glucose if people aren't perfectly healthy. So it's very common for people to have hormones not operating quite rightly. So you see this particularly in diabetics and people like that. And very often diabetics, if they eat an extremely low carb diet, will have very high fasting blood glucose. And if they eat a little bit more like 20% carb diet, then their fasting blood glucose will be much lower. So if the liver has enough glucose stored and it's glycogen and then it can control blood glucose much better. If carbs are really scarce, then your body has all these hormones that it releases to help manage it, including stress hormones like cortisol from the adrenal glands, other hormones, thyroid hormones get adjusted. So there's all kinds of things going on. And if your body, if you have some kind of diseases, so they're not coordinating quite as well as they should, then you can get some very high fasting blood glucose.

Yeah. So it sounds to me like the people who are eating very, very low amounts of carbohydrate would actually be the worst candidates to throw in like a high carb meal or something like that because their body's going to rebound so significantly in terms of their glycemic response.

Yeah. So at least the first meal that they eat, but then they'll handle the second meal better and then the third meal better.

So, you know, for say like somebody eating a low carb or a ketogenic diet, it sounds like they would benefit from really making sure that if they are going to have a high carb meal, that it's timed around a period of insulin sensitivity, such as the post exercise window.

Yeah, I think that would be a good time to do it. You know, you can also, if you, if you take a little bit of fruit beforehand, that can have a sort of catalytic effect. It helps the liver store some of the carbs that you eat. So yeah, there's various things you can do. There's also things you can do to slow down the rate at which the carbs are digested. So if you eat your carbs as part of a meal which has Vegetables for fiber, which has fat and which has an acid. So acids really help to slow down the rate of entry of carbohydrates into the body and help you manage blood glucose better. So things like vinegar, lemon juice, fermented vegetables will typically contain acids, like lactic acid, for instance. And you know, so those things can really improve your glycemic control.

Gotcha. Okay, cool. So we've talked a little bit about protein, protein toxicity ranges and your recommended kind of 15 to 30% of protein intake. We talked a little bit about carbohydrate and how it ranges, but it's right around, it comes out to right around like 15% to, depending on how active you are, up to around like 30% again. Right. Is what it seems like from what I'm getting in your book.

Yeah, I would say for adults like 25 to 30% carbs is usually pretty normal. You can go lower. So our ketogenic diet recommendations are down around 10 to 15% carbs. And then for athletes, if you're kind of a high intensity athlete, like a sprint athlete, then you may want to go closer to 40% carbs. So it's, you know, there's some variability and younger children need higher carbs. So 40%.

And I think what's important to explain to people is that, you know, I don't know about you, Paul, but a guy like me, like, I don't actually sit down and calculate this stuff. I just eat meals that are comprised of a balanced range of nutrients, particularly using a lot of the foods that you describe in your book and hopefully get a chance to get into some specific foods too. But yeah, I don't want people to think they have to stress themselves out counting this stuff. And as much as paying attention to kind of the approximate quantities, the general idea of being able to picture in your head about that 25 to 30% protein, 15 to 30% or 25 to 30% carbs, 15 to 30% protein and some fat. But in terms of fat, I think you have an interesting point in the book. You talk about a high fat diet being able to help you put produce more muscle. I think some people have a hard time wrapping their heads around how fat could help you make muscle. Now what's your argument there?

Well, so biologically, what's really going on? The way your body really wants to work, it doesn't want to burn food for energy, it wants to burn tissue for energy. So if you think of a cell, imagine that you're eating one meal a day the way the Cell wants to work is, you know, most of the day you're not eating. And instead of pulling the energy it burns from the blood, what it does is it is it pulls from its own internal constituents. Cells have their own glycogen reservoirs that it can pull for glucose. They have their own protein that it can burn. They have their own fats on all the membranes in the cell, and they can pull fats off those. They have their own little adipose tissue called liposomes, that about 1% of the energy in a cell is just these little fat droplets inside the cell. So they have all these resources. So a cell is like a miniature person, and they just draw down those resources over the overnight fast. And then when you have a meal, you know, so the cell sort of shrinks in the overnight fast. And then when you have a meal, it rebuilds itself. So the healthiest way to eat is actually reproducing, you know, giving the cell back all of the things it wants to rebuild itself, you know, so cells sort of cannibalize. Your body cannibalizes itself during a fast and then rebuilds itself after a meal. And the thing that best supports building tissue is to provide the macronutrients in exactly the same proportions the cell is composed of, because those are the proportions that the cell will deplete during fasting. So the diet that's just the right diet on general principles, also happens to provide just the right mix of stuff to build new tissue. So if you think you're building new tissue, you need to recreate new cells, new extracellular matrix from the ground up. That's what you provide, and that's what will make the construction of muscle the easiest. Whereas if you give a totally different mix, it's like if you're trying to build a building and you get all of the pieces that you need for the building in just the right proportions, then the building team can construct a building with nothing left over. But if you gave them three times as much plywood as they need, then they build the building, and they still have all this plywood left over. Well, that's what happens in a lot of people's diets. And what happens is the extra stuff that's left over has no place to go except to adipose tissue, you know, and so their body composition just isn't as good.

Gotcha. So basically, muscle is able to store some amount of fat. One way to increase the number of muscle cells is to make sure that you get adequate fat, is what it sounds like.

Yeah. And it's not only that they can store fat inside them, but they're composed of it. So over half, you know, if you took a cell and cannibalized it completely, over half of the energy inside would be from fat in the cellular membranes. And that also brings us to the issue of fatty acid mix. So most of those fatty acids are saturated or monounsaturated. So you have a pretty small component of polyunsaturated fat. So you don't want to eat too much polyunsaturated fat in your diet. The more saturated fat that you eat, the more your body is going to be able and eager to construct muscle.

So that means somebody who wants to put on muscle and it wants to avoid that protein toxicity range that we talked about by not getting more than 30%, which frankly a lot of people trying to put on a muscle exceed. They're going to benefit from saturated fat sources like coconut oil, like butter, like a good raw form of yogurt, or non commercialized dairy. Stuff like that.

Yeah, yeah. If you want a really good body composition and to build muscle easily, then higher saturated fat is the way to go. And that's why breast milk and milk of all species is very saturated fat rich. It's just the best for building tissue.

Gotcha. So I want to talk a little bit now that we've hit on proteins, carbs and fats, sugary foods, and you have a ranking system that's kind of unique for sugary foods. And we talked about fruit just a little bit bit. You talked about how if you're on a low carb diet and getting in a high carb meal, that fruit can mitigate some of that insulin response. But when you're ranking fruit and other sugary foods, you choose what's called a potassium to fructose ratio to define how good or bad for your body that sugary food is going to be. Why do you choose the potassium to fructose ratio? What's significant about that?

Well, it's a little bit arbitrary. So, you know, we're not saying that's a perfect measure, but, you know, basically you want some kind of measure of nutrient status. You know, so one of the things we look to fruits, berries, vegetables for is micronutrients. And potassium is an important nutrient for the body. Most people get too little of it. It's a very important electrolyte. And, and so that's one nutrient. And it's present in all plant foods. And we rely on plant foods for it. Mostly the low calorie plant foods like vegetables and fruits and berries. So that's sort of a good indicator of nutrient density. And then fructose is the most harmful thing in a lot of fruits and berries and vegetables. So we don't really want to eat a lot of fructose. It doesn't do us much good. It tends to, It tends to be bad for our gut flora and bad in other ways. So the potassium to fructose ratio is just taking a measure of something, an index of what's good on the nutrient side and an index of what's bad on the toxins side and saying we want to get the highest ratio of nutrients to toxins that we can. And, you know, so I thought that was just an educational way to kind of look at these fruits and berries and other plants and see where they came out. So some things come out really high, like tomatoes, potatoes, some things come out really low, like apples and pears. And you know, I understand heritage breeds of apples and pears are much better, but most of the grocery store ones have been selected for sweetness and they just have a lot of fructose, very little nutrition.

Okay, interesting. So the fructose to potassium ratio, I think that's a useful chart in the book. And just to clarify, in terms of fructose, you and Robert Lustig and lots of other folks out there seem to be somewhat against fructose consumption. But I do know that you eat fruit and you've got fruit recommendations in your book and starchy carbohydrate recommendations in your book. So in terms of what you think would be an okay amount of fructose, if you were going to paint a picture of the average person's perfect health diet, especially far as, let's say, both their consumption of fruit or natural fructose based sources, as well as some of these starchy foods, what would it look like in terms of how much you'd be consuming each day?

Yeah, well, in terms of the macronutrients, which nobody thinks in terms of, but just for background, I'll give it to you. We think we said something like 30% carbs is probably a typical diet diet for most people. And it would be good to get about 25% of energy as glucose and 5% of energy as fructose. So basically five times as much glucose as fructose. And so when you translate that to plant foods, you find that means that you need to eat some starches because starches are entirely glucose. But most sugary plants are closer to 50, 50. So if you're going to keep the fructose down to 5% of energy and the glucose up at 25%, then you need to get most of your carb calories from starches. So things like white rice, white potatoes are really good. We have a bunch of others, what we call safe starches. But it turns out in terms of plant foods, most of the sugary plants have as many calories per pound as the starches do. So like white rice, white potatoes are pretty close to 500 calories per pound. A lot of the fruits and berries are more like 200 calories per pound. So it actually works out pretty well if you just try to eat each day like one pound of our safe starches and one pound of kind of sugary plants, which could be fruits, berries, or they could be things like beets or carrots, which are also sugary. It turns out it's probably beneficial to get that modest amount of fructose, so it helps the liver regulate glucose better. Our basic advice is eat each day, try and eat about one pound of a safe starch, about one pound of a sugary plant food, then as many low calorie vegetables as you like. So those would be things like tomatoes, mushrooms, onions, garlic, spinach, you know, seaweed, any kind of vegetable. Just eat as much of those as you like. Don't count them as a calorie source.

Gotcha. So you're definitely not saying, oh, don't go, no, fructose, it's. It's evil. But it sounds like it'd be the equivalent of right around more like two. Two or so pieces of fresh raw fruit.

Yeah, yeah, I think, you know, two or three pieces. I. I typically eat maybe one or two. You know, I think, you know, two or three fits our diet.

Yeah, that's one area. You know, even though I follow a lot of the concepts of your diet, I have nothing against fructose, but I personally probably have the equivalent of about two pieces of fruit a week. It's just not a huge part of my diet. I tend to do a lot more the starchy vegetables than I do the fruits. But I have other sources of fructose in my diet, such as some of my engineered sports fuels and stuff like that. So a few other things that I wanted to touch on with you. You talked about basically in the book a little bit about hunger and weight loss, and you specifically touch on trying to lose weight and why you need to be careful with a low daily calorie intake. Now, if you are trying to lose weight or shed fat, what do you think the lowest daily Calorie intake should be for folks. And why?

Well, what I recommend is. Well, first of all, what I recommend is being very well nourished in order to lose weight. So you know, we think being malnourished is a major cause of hunger and appetite. It's a major cause of, you know, people failing on their diets. It's a major cause of yo yo weight regain. So you know, often a diet will work great and you can lose weight easily on it for a month or two or three. But then you get malnourished in something and you get hungry and you start eating and your weight balloons up. And so it's really important to keep your body well nourished, you know, give it everything it needs to function properly. And you know, basically the design of our diet, we go through every nutrient and we try to figure out what's the optimal amount to give your body. And during weight loss you don't need to give your body as much fat as you normally do because you're pulling fat out of adipose tissue as you're losing weight. So you have those inner stores of fat that you can call upon. But other things generally you still need to provide in diet. And even some fats you need to provide, there's lots of fat associated nutrients. So things like choline and other compounds that help you make cell membranes, things like the fat soluble vitamins like vitamin A, vitamin D or things that are associated with fat like folic acid and some other things. So there's a lot of things that there's a lot of reasons why you can't really be well nourished unless you're eating some fat, unless you're eating some plant foods, getting some carbs, getting some protein. In order to maintain optimal nourishment while you're losing weight, you pretty much need around maybe 1300 calories. So something like 500 carb calories, 300 protein calories and 500 fat calories with the fat calories coming from well chosen sources like eggs, liver, you know, nourishing foods. So you know, so I think once you get down to about 1300 calories, you know, then if you want to lose weight faster, I would say go out and do more exercise. You rather than cutting food intake even more.

Now what about hunger? Do you think that during that time of a low daily calorie intake, if we're going to cut as low as 1300 calories while trying to shed fat, is it normal to be hungry, to lie awake at night biting your lip, to kind of Feel constantly like you have to eat, or what's your feeling on hunger?

No, I think if you're eating well, you should have minimal hunger. So you may have a mild discomfort feeling of desire for food, but it should be something that it's very easy to resist, and you can easily get distracted from it. So if you get busy at work, then you forget that you're hungry or you go exercise, and the exercise suppresses hunger, you know, so that's the kind of level of hunger that I'm talking about. It shouldn't be something that, you know is constantly in your thoughts. And, you know, basically I interpret hunger. You know, hunger is the brain's understanding that you're malnourished and that you need food in order to be healthy and function properly. And our brain evolved all these mechanisms for detecting that you need food. So it's usually not a dumb. You know, the brain is usually not making a mistake. So if you're getting hungry, there's probably something that you need that you're not giving yourself, and it's worth your while to try to figure out what that is. And if you are supplying everything you need and the only thing you're missing is a little bit of fat, which is already present in adipose tissue, then your brain won't feel hungry. It'll just say, all right, take that fat out of the adipose tissue, release it from our fat cells and leave it there. Then we have everything we need. So it won't make you hungry and you'll be gradually losing all that extra fat.

Yeah, it makes sense. And in terms of something kind of related to that, you touch on fasting a little bit in the book. Are you a fan of that? And if so, do you kind of have an optimal fasting scenario for people? A lot of folks out there do intermittent fasting and wonder how long they're supposed to do it, that type of thing. So what do you recommend as far as that goes?

Yeah, I'm a big fan of fasting. You know, it's not for 100% of people, but I think probably at least 90% of people should be doing intermittent fasting. I personally don't recommend fasting longer than, say, 23 hours. And I think, you know, what I do is typically 16 or 17, sometimes 18 hours, you know, but basically 16 hours is what I. What I aim for, and I do it every day. So one of the important points here, there's a couple of important points. One of them is if you fast too long, you'll end up Doing more harm than good. So, you know, fasting depletes protein within the body. You have no protein store. So it's not like fat, where if you're missing fat, you're not going to become deficient in fat for a while. With protein, you become deficient very quickly, and the first place you become deficient in are basically the liver and the kidneys, and you lose your ability to detoxify toxins and you become much more vulnerable to environmental toxins and to infections. And so, you know, typically one thing that happens is that a lot of aspects of immunity, immunity is closely tied to metabolism and food. And in a long fast, a lot of aspects of immunity either get suppressed during the fast when resources are scarce, or during the refeeding when your body is trying to rebuild protein supplies. And it turns out the same process by which you cannibalize protein is the way you destroy bacteria and viruses within cells. So if you go through a long fast and then you start refeeding, then your bacteria and viruses get a, you know, a free pass for a few days or even a few weeks. And that's why when people refeed after famines, then you often get very high rates of disease like malaria, tuberculosis, things like that, not during the fast, but during the refeeding. And so, you know, very long fasts are, tend to be health damaging, but shorter fasts are extremely healthy. And another aspect of this is that food influences our circadian rhythms, and circadian rhythms are extremely important in health. And so you want to, if you can eat during daylight hours. And one of the nice things about intermittent fasting is that if you time your meals properly, they can support and enhance your circadian rhythms. And that can really improve health over the long run and probably longevity quite a bit also.

Yes, when it comes to the whole fasting, hunger and weight loss component, it sounds like one of the keys that you're saying is to make sure that you at least, least allow your body to be in that state of nutrient balance and make sure that the foods that you are eating are of a high quality.

Yeah, that's right. I think especially when you want to lose weight. If you're like a young child who eats a lot of food in comparison to body weight, then you don't have to be as selective for high nutrient density. Kids can eat a lot of muffins and stuff and still be healthy, but if you're an adult already, your calorie intake is down, and then if you're on a weight loss diet, your calorie intake is down even further. It's pretty hard to get all of the nutrients you need to be fully healthy. So you really have to make a focus if you're on a weight loss diet at eating nutrient dense foods.

There are in your book a variety of supplement recommendations and a lot of other topics that we barely even had time to scratch the surface on. But you know, I get a lot of questions from people about what diet I endorse and what diet I recommend. Am I a paleo diet guy, you know, am I a vegan vegetarian type of guy? And you know, just so people listening in know this book with a few modifications to support the active lifestyle and then also some attention to the ketogenic portion of the book. Especially for people who I coach, who are like endurance athletes who I need to kind of turn into fat burning machines before getting them into to a little bit higher or moderate carbohydrate based intake. This is a diet that's very, very close to what I personally follow. And so for those of you who are asking me that question wondering, grab the Perfect health diet and read through it because that's going to give you a very good basis of understanding. And hopefully what we went over with Paul today got you introduced to the basics behind the diet. But I'd still recommend you grab the book and check it out. I'll link to the book in the show notes, of course, and if you have questions, comments, feedback, you can leave them there. Over@BenGreenfieldFitness.com Paul also has a great blog. And your blog is what again, Paul? Perfecthealthdiet.com Paul's is perfecthealthdiet.com it's one of the blogs that I personally follow, so I hope that was helpful for everybody. And Paul, you're just a wealth of knowledge and I want to thank you for coming on the call today.

Thank you for having me, Ben.