
In this conversation, Rob explains why sugar is so damaging and explains that just like alcohol, our bodies can cope with sugar in small amounts. But in excess will end up in the liver and ultimately trigger us to get sick.
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Dr. Robert Lustig
We underwent a revolution back in the 1930s 40s with antibiotics where we thought a pill could treat everything. Now we're undergoing a revolution where we realized that was a mistake. It's Time to Rethink Health it's time to rethink health care. You can't fix health care till you fix health. You can't fix health until you fix diet. And you can't fix diet until you know what the hell is wrong. And what you thought was wrong was basically propaganda for the last 50 years.
Rangan Chatterjee
Hi, my name is Rangan Chastjee. Welcome to Feel Better. Live More. My guest on this week's podcast is Dr. Robert Lustig. Now, Robert is a professor of Pediatric Endocrinology at the University of California, but he's also a leading public health expert who for years has been eloquently exposing the myths of modern medicine and the food industry. One of his great passions is communicating how sugar and ultra processed food is fueling the chronic disease epidemic that we are all facing today. Obesity, type 2 diabetes, metabolic syndrome, heart disease, and so much more in Robert's view, are primarily caused by the foods that we are eating. In his latest book, Metabolical, he outlines what he calls the Hateful eight the eight root causes in our body that underlie all chronic disease and explains how food can impact every single one of them. In our conversation, Rob explains why too much sugar can be so damaging and explains that just like alcohol, our bodies can actually cope with sugar in small amounts, but in excess that sugar will end up in our liver and ultimately trigger us to get sick. Rob's decades of clinical experience and research has led to his bold and compelling assertion that the answer to all chronic disease can be found in real food. And in our conversation, Rob explains exactly what he means by that term. Now here's advice to all of us when it comes to eating is to protect the liver and feed the gut. And I think these six words are a really elegant way of summarizing the nutrition advice that all of us should consider taking on board in order to improve our health and well being. We cover so many different topics in this conversation, including why sugar sweetened drinks are so disastrous for our health, but also why diet drinks can also do just as much damage, if not more. We also talk about something called tofi t o f I thin on the outside and fat on the inside. And fascinatingly, Rob outlines the three different types of fat gain that we can all experience subcutaneous the fat that we can see visceral the stress related fat that we often get around our middles and liver fat. And really importantly, it's only the first of these three patterns that you are likely to notice. But it's the latter two which we really need to fix, especially as they're already appearing in kids. Yes, this conversation is full of mind blowing facts and insights, but it's also really, really empowering. There are simple practical tips that all of us can use to improve our own lives and the lives of the people we love. I hope you enjoy listening. And now my conversation with Professor Robert Lustig.
What are the key negatives when we consume too much sugar or I guess the levels of sugar that many of us are currently consuming?
Dr. Robert Lustig
Well, first of all, let's make it very clear that sugar is not the only problem in in our diet. It's the big one. It's the 2000 pound gorilla in our diet. But there's other stuff too. But sugar is a particularly egregious molecule. Once upon a time, trans fats were the worst thing we consumed. Trans fats are the devil incarnate trans fats, the bacteria can't chew it up, which is why they put the trans fats in so that it would last forever. The ten year old Twinkie. Well, the fact is our mitochondria, our little energy burning factories inside all our cells are really refurbished bacteria. We can't chew it up either. The exact same reason for why they put the trans fats in the food is exactly why you shouldn't eat the food. Now we know that and they've come out of our diet. Now sugar is public enemy number one. What does sugar do? The answer is a whole bunch of bad things. The food industry says sugar is energy. Well, they're correct if you're a bomb calorimeter. If you just blow it up, if you explode it, yeah, you get four calories per gram. But we are not bomb calorimeters. Turns out that sugar actually poisons the mitochondria. It poisons it at three separate enzymes that are necessary for mitochondria to do their job. The first one, AMP kinase, which is the fuel gauge on the liver cell. The second one, ACAD L ACYL CoA dehydrogenase long chain, which is necessary to get fatty acids into the mitochondria to be able to oxidize them to create energy. The Third one is CPT1, carnitine palmidival transferase 1, which is the enzyme that regenerates carnitine, which is the shuttle mechanism that brings the fatty acids into the mitochondria. In the first place. In other words, when you consume sugar, you are poisoning your mitochondria. You are generating less of the chemical energy that our cells get powered by, called ATP. If you're making less ATP, is that energy? It's the opposite of energy. When you consume sugar, you are actually inhibiting your body's energy production. Can you think of a chemical that inhibits your mitochondria and reduces ATP production? Cyanide. Cyanide. Does that sugar and cyanide do the same thing? Now? Obviously not as severely. Cyanide. Parts per million keel over and die on the spot. With sugar, it's in the parts per thousand and you don't keel over on the spot, but you feel lousy. And over time it's going to take its toll. But ultimately, if you're inhibiting your mitochondria, you are poisoning your body. We now have the data to show how that occurs. Here's my question to you and your audience. Sugar is in virtually all ultra processed foods and ultra processed foods are now 56% of the UK diet. And the amount of sugar that Brits eat, 62% of it is found in the ultra processed food category. So my question to you and your audience is, is ultra processed food food?
Rangan Chatterjee
My view is that it's not really. I would say no, but I know to many people that is super controversial, which we're definitely going to talk about. But yeah, on a straight answer, I would say no. Depends on your definition, I guess, because it's energy, it's got some calories in it, which we consume in our mouth that enable us on one level to sort of. I guess you're saying it's actually reducing the energy production, the sugar within it anyway. But yeah, on one level it sustains people and they can actually get on with their days, at least in the short term anyway.
Dr. Robert Lustig
Well, you have to know what the definition of food is. If I had my Webster's dictionary right here, right now, you guys in the UK probably don't use Webster's. You probably have something else. But if I pulled it off the shelf, it would say that the definition of food is the following, and I have no problem with this definition. Substrate that contributes to either the growth or burning of an organism. That's the definition. I have no problem with that definition. It's a fine definition. Substrate that contributes to either the growth or burning of an organism. We've just talked about burning sugar does not contribute to the burning of an organism. It actually inhibits the burning of an organism. Dr. Kevin hall, at the NIH did a study where he showed that when you give people ultra processed food, they burn less and gain more weight when everything else is controlled for compared to the same diet in real food. Did this in 2019. Ultra processed food does not contribute to burning. Now let's go to growth. Does ultra processed food contribute to growth? My colleague, Dr. Efrat Manseniga Ornan, who is the chairman of the Department of Nutrition at Hebrew University Jerusalem, just published three papers in bone research showing that ultra processed food actually inhibits skeletal growth, inhibits the ability of bones to increase in length and in width. In addition, we know from the Neutronette Sante study and many other studies that in fact what sugar does is it feeds cancer cells, it hijacks growth. Sugar doesn't contribute to burning, inhibits it, doesn't contribute to growth, inhibits it or hijacks it. I pose the question to you again, Ranga. Is ultra processed food food?
Rangan Chatterjee
I'll go with my original answer, which is no.
Dr. Robert Lustig
That is right. It is no. Ding, ding. That's right. But the point is that the food industry refuses to go there. The populace refuses to go there, the governments refuse to go there. And you and I are both interested in mitigating chronic disease. And you are right. If you get people on a real food diet, you can mitigate virtually any and all of their chronic diseases. I completely agree. You gave a TEDX talk basically saying you can basically take away somebody's chronic disease. I used to do that in my clinic when I was practicing routinely, but only if they change the food. If they didn't change the food, no amount of medicine I threw at them could make a difference.
Rangan Chatterjee
Yeah. What strikes me as a really key message is that the majority of what we are buying to feed ourselves and our families is ultra processed food, whether it's here in the UK or with you in America. And that is contributing to this tsunami of chronic ill health that we're seeing. It's pretty, you know, it's pretty alarming. But what I think is so key, Rob, for me is that it's so normalized now. Like it's the norm everywhere. Schools, hospitals. In fact, if you want to go down the real food route, you almost feel like a bit of a. Like, you know, if you try and do it with your kids, you actually become a social outcast in some ways. And I think this is the problem. It's just, it's the norm. We've moved so far away from what.
We used to do.
In fact, maybe this is a good Time for you to explain what you used to do when you were 8 years old. Because I believe you had a granddad who lived in Brooklyn and every Saturday you would do something which I think beautifully illustrates his points.
Dr. Robert Lustig
That's right. So, yeah, bottom line is I completely agree with you. What we've done is we've normalized it. Once upon a time, it was actually not normal to eat ultra processed food. And today it is normal. I remember when that happened because it happened to me. It happened to me in two ways. On Saturday afternoons, my family would go visit my grandparents who lived about eight miles away in Brooklyn. And my grandfather would walk me down to the corner grocery store to buy a comic book and a six and a half ounce bottle of Coca Cola. I remember pretty much every Saturday afternoon. And that was the big treat. The comic book and the Coca Cola that was on Ocean Avenue and Avenue and in Brooklyn. The fact is that that was once a week and it was six and a half ounces. Today, children are consuming about, I think, 35 ounces a day, you know, median. So they are getting about six times the amount of sugar that I did from that one coat. And they're doing it every day instead of once a week.
Rangan Chatterjee
In addition, I mean, that's just. Could we just pause on that for a second? You're saying you had 6 ounces once a week, and we're assuming back then that the rest of your diet throughout the week was low in sugar, low in processed foods, sort of a real food diet.
Dr. Robert Lustig
Well, my mother worked three jobs and so I ate a lot of Swanson TV dinners when they first came out. And I remember when they came out around 1964, you know, the fried chicken, the Salisbury steak. I hated that Salisbury steak. And I actually. She trained me on how to turn the oven on and how to heat them up because often she wasn't home at night, you know. So, you know, to some extent, I was a latchkey kid because my mother worked so hard. My father was in Manhattan all day. And so I basically had it sort of take care of myself. And sometimes I had to eat dinner out of the freezer. And so I remember those Swanson TV dinners. And they were a problem. They're still a problem. So you put the two together. And that was the beginning of the, shall we say, onslaught of processed food in the United states about the mid-60s. Then things picked up even more in 1975 when we started substituting high fructose corn syrup for sucrose because it was half as expensive and it Was homegrown. Then finally, the piece de resistance came in 1977 when the McGovern Commission released its report saying that we all needed to eat less fat to try to prevent cardiovascular disease. Well, when you take the fat out of food, it tastes like cardboard. And so what did the food industry do? It basically replaced the fat with sugar. That's why we ended up with Intenmann's fat free cakes and the like. And that was when the pasta craze first hit was refined carbohydrate because it was low in fat, et cetera. And now we're off to the races and it's just exploded ever since.
Rangan Chatterjee
Is it the sugar that's inherently bad in and of itself or is it the excess amounts? I mean, or is it both? Right? Because I think a lot of people might say, well, look, you know what, this never used to be a problem, right? We would have the odd sweet treat now and again. And actually there's quite a few prominent scientists, you're well aware, we say, actually, sugar's not a problem. Sugar's actually fine.
Dr. Robert Lustig
We're working on it. I have a bone to pick with some of those scientists and we can argue that and talk about that, if you like, as to exactly why they say what they say. So here's what I can tell you. There are social drinkers and there are alcoholics. Now, social drinkers can pick up a beer and put it down and they don't need one. Every day alcoholics pick up whiskey and can't put it down and they need it three times a day, right?
Rangan Chatterjee
Yeah.
Dr. Robert Lustig
Did the one beer that the social drinker drink hurt them?
Rangan Chatterjee
Unlikely.
Dr. Robert Lustig
Unlikely, Unlikely. The reason it's unlikely is because there is what is known as a first pass effect. You drink the alcohol in the beer. First of all, it's very low percentage. It's only 3.6% in a beer that is about 60 calories worth or so of alcohol. What happens is that the first pass effect, the stomach and intestine metabolize that alcohol before any of it ever gets to the liver. The amount that actually hits the liver that could do damage is exceedingly small. As long as you're not following up with a second beer and a third beer and a fourth beer and a fifth beer, like can happen at the Newcastle Publishing. You don't usually have a big problem, but if you keep doing that, then that is a problem. It's a dose dependent phenomenon. And your intestine is there to try to protect your liver from getting the onslaught before it will do damage. Same with sugar. No difference. Your intestine can take a small amount of sugar that you consume and can actually turn it into fat in the intestine. Intestinal de novo lipogenesis, the process of converting sugar to fat into VLDL in the intestine so that it will not go straight to your liver. About 10% of an initial sugar bolus will undergo intestinal DNL and therefore be diverted away from the liver and into the bloodstream as vldl. Now, that VLDL is not great for you because it could ultimately cause heart disease, but it's protecting the liver. But if you consume past your intestines capacity to do that, now, the rest of it's going to end up in your liver. The problem with sugar in the liver is exactly the same as the problem of alcohol in the liver because it causes the exact same processes. It causes glycation, it causes oxidative stress, it causes mitochondrial dysfunction and basically drives insulin resistance. This phenomenon that we now know is at the base of virtually all chronic metabolic diseases. Therefore, your pancreas has to make extra insulin to make the liver do its job. Because now the liver's not working right because it's been poisoned. Insulin levels rise all over the body. And now you've got the risk for Alzheimer's, you've got the risk for heart disease, you've got the risk for cancer, you've got the risk for virtually every other chronic metabolic disease on the plate, all because of what happened to your liver and fructose, that sweet molecule. And sugar basically has the same fate as alcohol. So when people say, oh, a little sugar is fine, the answer is, yeah, because your intestine diverts that little bit away from the liver as soon as you overwhelm that capacity. Now your liver is right in the crosshairs and that's when chronic disease is going to start.
Rangan Chatterjee
Yeah. Rob, you're a pediatrician. I've seen videos of you talking with passion about this exact topic maybe 15 years ago, still online, something like that. When was it, when was the first time for you that you started to think, you know, what's going on here in the book? You have been pretty. It's pretty provocative at times. I actually agree with it. So I like it. You've really gone out there, you've sort of. You've ripped into modern medicine at times, and we're definitely going to talk about that. But when was it? Because you do have this sort of incredible passion and energy to get this message out there. And I'm just wondering, what was it in your clinical experience that actually really got you into thinking, there must be another way here? This can't be right.
Dr. Robert Lustig
Well, so I had three aha moments. Three. And that sort of got me to where I am today and why I'm saying what I am saying today. The first aha moment came when I worked at St. Jude Children's Research Hospital in Memphis, Tennessee Pediatric Cancer Hospital. I went there in 1995, and I was presented with a cadre of about 40 children who had survived their brain tumors because of surgery and radiation, sometimes chemotherapy, who had become massively obese. They were perfectly normal weight before the tumor, and now they were on the order of 350 to 400 pounds. Normal kids before the tumor and now massively obese. There's a name for this. It's called hypothalamic obesity. It was first written about or first described in 1901 by Friedlich and Babinski, two of the greats of international neurology. And I had all these kids with hypothalamic obesity that I had to take care of. How do you get them to lose weight? How do you get them to get better? It had been shown previously that diet and exercise is useless. In fact, George Bray, the father of obesity research in America, in 1975, had taken eight of these kids on his ward and fed them 500 calories a day for a month. What do you think their weight did?
Rangan Chatterjee
Well, you would expect it came down, but I suspect in this case it probably didn't.
Dr. Robert Lustig
It went up?
Rangan Chatterjee
Yeah.
Dr. Robert Lustig
Okay, 500 calories a day and their weight went up. How does that happen? The answer is it happens because they were burning it slower than they were taking it in, because their metabolism of calories had actually come to a virtual standstill. Even 500 calories a day was too much. When these kids have no energy, they sit on a couch, they're not interested in anything. The parents would actually complain that that was the worst thing about this. They'd say, this is double jeopardy. My kid has survived the tumor only to succumb to the therapy because my kid is a lump on a log. And he's lost interest in everything. He's lost interest in school, he's lost interest in life, he's lost interested in activity, he's lost interest in friends. He's lost interest in everything. All he wants to do is sit and sleep. And so I had to take care of these kids. So I went to the literature and I said, oh, the other thing was that this was exactly when the hormone leptin had been discovered. Leptin was discovered in 1994. And I was prepared for that discovery because I worked at Rockefeller University with the guys who discovered it. Jeff Friedman and Rudy leibel, all the MDs at Rockefeller University all had to take call in the hospital together. So we were always trading call dates and everything. So everybody knew what everybody else was doing. I knew that they were trying to clone this hormone out of these mice. When they did in 1994, I was very prepared for it. I moved to St. Jude and I had these kids, and it's like, what am I going to do for them? And I postulated right then that these kids must have leptin resistance. These kids can't see their leptin. And the reason is because their hypothalamus is dead, because we killed it, because of the tumor or the surgery or the radiation. And so because they can't see their leptin, their brain thinks they're starving. The question was, okay, their brain thinks they're starving. What's downstream of leptin? What's actually making them gain the weight? The starvation is why they're hungry, but what's making them gain the weight? Well, we knew that these kids made a lot of insulin, and we knew that there's this animal model of damaging the hypothalamus, and they put out enormous amounts of insulin. And you could actually stop that by cutting the vagus nerve. The vagus nerve is the nerve that leads from the brain to the pancreas, and then the insulin would go down. I said, well, I can't cut their vagus nerve. I'm not a surgeon, and that's a little drastic. But what if I gave them a medicine that suppressed their insulin release? We gave them a drug called octreotide, a drug that is used by endocrinologists to usually suppress growth hormone release, but it also suppresses insulin release. So we repurposed it and we gave it to these kids. And lo and behold, they started losing weight. They couldn't lose weight before George Brady showed they gained weight, but they were losing weight, and something even more remarkable happened.
Rangan Chatterjee
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Dr. Robert Lustig
They started exercising spontaneously. One kid started competitive swimming. Two kids started lifting weights at home. One kid became the manager of his high school basketball team, running around collecting all the basketballs. I mean, these were kids who sat on the couch, ate Doritos and slept. And now they're active again. And the parents would say, oh my God, I've got my kid back. And the kid would say, this is the first time my head hasn't been in the cloud since the tumor. So something had changed their relationship to the world. Not just their relationship to food, but their relationship to the world. We said, this is very interesting. We did a double blind, placebo controlled trial and this time built a quality of life measure into the protocol. And sure enough, the lower we got the insulin with the drug, not only the more weight they lost, but the more active they were. What this did, the reason why this is so important and the reason I'm spending so much time on it, Ranga, is because this turns the first law of thermodynamics on its head. Because the standard interpretation of the first law goes like this. The first law is the total energy inside a closed system remains constant. Energy can neither be created nor destroyed. Just shifted around. The standard interpretation that we learn in medical school and what the general public learns is if you eat it, you better burn it or you're going to store it, in which case the storing part, the fat gain, is secondary to the primary problems, which are the eating and the burning, the gluttony and the sloth. Therefore, the weight gain is secondary to the gluttony and the sloth. Therefore, it's about behavior. Fix the behavior, fix the weight. What we showed in these kids was, it's exactly the opposite. Turn it around. What we showed was if you're going to store it, that is a high insulin level leading to obligate weight gain. And you expect to burn it. That is normal energy expenditure for normal quality of life. Because energy expenditure and quality of life are synonyms for each other, then you're going to have to eat it. And now the storage is primary and the behaviors are secondary. The gluttony and sloth are actually because of leptin resistance.
Rangan Chatterjee
We get sick first and then the weight comes afterwards.
Dr. Robert Lustig
That's right. We get sick first and the weight is secondary. That's exactly right. So this is monumental. This is huge. But of course it goes against everything that we are taught and it goes against everything that doctors routinely believe. But this was my first aha moment. My second aha moment came in 2006. So I realized that insulin was the bad guy. And we started then changing what we did in clinic. Instead of worrying about weight, we worried about insulin. We said, get the insulin down any way you can. And that's what my clinic became. It became an insulin reduction clinic. It wasn't a weight loss clinic, it was an insulin reduction clinic. And when we got the insulin down, then they lost weight. So in 2006, I was asked to give a talk at the NIH, specifically the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. They were having their 100th anniversary of public health and it was a two day symposium. The first day was on their successes like lead poisoning and pollution and asthma. Things they'd figured out and been able to do something for the public health. The second day was on challenges. The morning was going to be obesity, metabolic syndrome, and this afternoon was going to be ADD and autism. They asked me to give a talk. What do you think is the single most important environmental exposure that leads to obesity and metabolic syndrome? And I figured they probably figured I was going to, you know, give a talk about some, you know, like BPA or some other, you know, environmental, you know, toxicant, you know, that's in the water or in the air, you know, something like that. And I thought, thought to myself, how am I going to, you know, make this worthwhile? And I thought to myself, all right, wait a second. Let's, let's, let's go backwards here. Children today get two diseases they never got before. Type 2 diabetes and fatty liver disease. Those two children never got those before. Now lots of kids get them. I looked up type 2 diabetes and fatty liver disease. And of course I know a lot about both of them, but I very specifically looked for origins and causation. It turns out that in the old days, back in the 1970s, before this pandemic of chronic disease started, both those diseases were the diseases of alcohol. Type 2 diabetes and fatty liver disease were the diseases of alcohol. But kids don't drink alcohol. So I said, all right, is there something they're exposed to that's like alcohol? So I opened up my Leninger biochemistry textbook from 1974, sitting at this table that I'm at right now, I said, what the hell is like alcohol? And there it was and stared me right in the friggin face, right off the page from 1974. And the answer was fructose. Fructose and alcohol are metabolized virtually identically. It makes sense that that would be the case because after all, where do you get alcohol from? Fermentation of fructose? It's called wine. We do it in nap and Sonoma every day. The big difference between fructose and alcohol is that for alcohol, the yeast does the first step of metabolism called glycolysis. For fructose, we do our own first step of metabolism. But after that, what the mitochondria see are exactly the same. Acetyl coa. It's just a question of which was the substrate, was it the ethanol, or was it the fructose. But ultimately they end up with the same fate. It's very clear all of a sudden looking at that right there, that this is the substrate that is driving Both the type 2 diabetes and the fatty liver disease. So I put together a talk and I went to North Carolina and I said, this is what I think's going on and here's why. Half hour talk. And then there was the bathroom break and I got my applause and then everyone left the room and they didn't come back. You know, I'm standing there at the podium talking with, you know, this person, that person, and no one's coming back for the next session. And then I had to use the bathroom. So I went out and I actually got tackled in the frigging bathroom of the NIH by a bunch of crazed toxicologists screaming at me, saying, oh my God, oh my God, you're right, this makes perfect sense. This is the toxin. You have to tell everyone about this. I guess I'm still doing it.
Rangan Chatterjee
I guess you still are.
Dr. Robert Lustig
So if the toxicologist went berserk, might be true. Then that was the second aha. And then the third aha was not even my aha. It was my colleague's aha, but I adopted it. So we got very interested in sugar here at UCSF after that. And we actually have a group of us we call the Sugar Hill Gang. They're actually referenced in the book here. But my colleagues Kristin Karnes, Laura Schmidt and Stan Glantz started looking at the paper trail of the food industry back in the 1960s and found the actual paper trail that showed that the food industry paid off scientists to exonerate sugar and finger saturated fat as the bad guy. We actually found their documents that showed the money transfer and the communications, just like what the January 6th committee is doing now. Follow the money. So we actually proved that the sugar industry put their thumb on the scale back in the 1960s to exonerate their product, because there had been data that had been coming out at that point showing that sugar was not good for you. In fact, that's what John Yudkin found, remember, pure white and deadly. And he had shown that data. And so people were starting to cast a fisheye at sugar. And so they had to go into overdrive mode to PR this problem away. And so they approached the chairman of the Department of Nutrition at the Harvard School of Public Health, Fred Stair, and his associate Marc Hegstadt, who ended up becoming the head of the U.S. department of Agriculture in 1970, to pay them off $6,500 back then, which would be about 50,000 today, to write two review articles to appear in the New England Journal of Medicine that basically said saturated fat's the bad guy and sugar is no problem whatsoever. That's the third aha moment. It's all a scam. The whole thing's a put up job. And that's why I wrote Metabolic.
Rangan Chatterjee
Sugar and Alcohol. I don't think people commonly would put the two things together. People, I think, like, you know, Joe Public, I think would, would think, okay, alcohol, I know if I drink too much, it's not good for me, it's going to cause problems with my liver. I think there's that understanding. And if I drink a little bit, have some days off a week, you know, you know, the odd glass of wine here and there is probably not going to be too bad for me, I think is what most people tend to think.
Dr. Robert Lustig
That's true. And, and, and that, and if that were the case, that would be true. And that's true for about the 40% of Americans who are social drinkers. You know, 40% of teetotalers don't touch this stuff, okay? 40% of social drinkers can pick up a beer, put it down like me, okay? But 10% are binge drinkers and 10% are hardcore alcoholics.
Rangan Chatterjee
Yeah.
But I don't think people think of sugar in the same way in terms of what it does for the liver. And I think that's a really, I think, eye opening comparison for a lot of people. The other thing you said, which I think really beautifully ties into the start of this conversation, is that you started running an insulin reduction clinic. And, and you know, like you, I'm very passionate in root causes and this idea that we've labeled all these so called separate diseases, we get taught about them at medical school as, oh, they're all separate entities. And for this treatment for this disease, you take this drug and you have this sort of treatment and we look at that downstream pathology, don't we? But you mentioned mitochondria at the start in terms of what sugar or excess sugar can do to mitochondria. And that, you know, mitochondrial dysfunction sits at the heart of so many different conditions. But also insulin resistance. Right. So that insulin resistance, that insulin lowering clinic actually would probably depending on who was coming in. I appreciate your pediatrician, but if, if all of us as doctors ran insulin reduction clinics, we would get rid of.
Dr. Robert Lustig
75% of the chronic disease in America, in the world.
Rangan Chatterjee
Exactly. It's that root cause again, isn't it?
Dr. Robert Lustig
Yeah, absolutely. I completely agree. Which is what I'm trying to, you know, bring to, you know, medicine. Unfortunately, you know, medicine is provincial. Medicine doesn't, you know, respond very well to, you know, new ideas. It's, you know, it's a, it's, it's a cartel, if you will.
Rangan Chatterjee
You're very critical of modern medicine. In the book, you say modern medicine treats symptoms. You say modern medicine is not the solution. I do indeed. And I agree with this. It's something I'm, it's one of my big frustrations in my what now? 20, 21 year career, seeing patients. If it's like, you know, I sometimes wonder if doctors honestly ask themselves sometimes at the end of their day, and obviously it depends where you work. I'm not talking about intensive care necessarily, I'm talking about chronic patients. And I did this once, Rob, I did this in general practice once. I asked myself at the end of the day, how many patients do you honestly think you've really helped today? And quite a few years ago it was 20%. I thought, I've only helped 20% of people. The other 80% I've done something. I've sent them off for a test, I've referred them, or I've given them a drug. But I knew they'd be back. I thought, I'm not really getting to the heart of this problem. That's right. I knew, and I kind of feel the patient knew it as well. And that's kind of one of the things that led me on this journey to try and understand that there must be a different way. And, you know, that's why I think Metabolic is such a wonderful book. It outlines the history, it outlines the science, but it also gives some really practical solutions.
Dr. Robert Lustig
You know, we treat medicine, and unfortunately, medical schools treat medicine like a big game of Clue. Colonel Mustard in the conservatory with the candlestick. Match the symptom card with the diagnosis card, with the treatment card and discharge your patient. In fact, in 1980, there was a game that we used to play in residency on Sunday mornings before things got busy in the ER called Intern. That was what you did. You basically took your symptom, you got a symptom card, you got a diagnostic card, and you got a treatment card. And once you got the three of them together, you got rid of the patient. Patient, first player to discharge all their patients won the game. And that's how we treated it. So these diseases got a meningitis, here's an antibiotic, got cancer, here's a chemotherapy. But the fact is, chronic disease doesn't really fit into that. There are eight, count them, eight chronic diseases that have completely taken over modern medicine.
Rangan Chatterjee
Eight.
Dr. Robert Lustig
And here they are. Type 2 diabetes, hypertension, dyslipidemia, cardiovascular disease, cancer, dementia, fatty liver disease, polycystic ovarian disease. Those eight. Those eight now account together for 75% of all healthcare costs. And none of them have a cure. None of them even have a treatment. But they all have a prevention. We're not preventing it. We're handing out statins or oral hypoglycemics or antihypertensives like candy. But that's treating the symptoms, the manifestations of the disease, not actually treating the cause. The reason is because those diseases are not really the diseases. What's going on underneath to cause. All eight of those diseases are exactly the same. They're just in different organs. Here are the eight things that I outline in the book, What I call the diseases that are not diseases. I call them the hateful eight. And here they are. These are things that people don't know because they don't have ICD 11 codes, and doctors don't know what to do. About them, so they don't even mention them. So no one's ever heard of them. And they didn't learn them in medical school either. So here they are.
Rangan Chatterjee
Eight.
Dr. Robert Lustig
Number one, glycation. Number two, oxidative stress. Number three, mitochondrial dysfunction. Number four, insulin resistance. Number five, membrane instability. Number six, inflammation. Number seven, methylation. Number eight, autophagy. Now, these are all normal phenomena that happen, but they can be speeded up or slowed down by what you eat. It turns out when you have control over all eight of those things, you will be 110 playing tennis. When you don't have control over those eight things, you will be 40 years old, in a wheelchair with two stumps, on dialysis, waiting for your next stroke. And of course, everything in between, those are the choices, those are the options. And because none of those eight, the hateful eight that I just mentioned, none of them have a cure. None of them even have a treatment. They only have a prevention. We're not preventing anything. And that's why you felt like you were not helping any of your patients, because you weren't addressing those eight root causes that you yourself know to be the big problem in medicine.
Rangan Chatterjee
It's like a leaking roof, isn't it? The roof's leaking and you just putting a bucket there to pick up the water. That's kind of what the drugs are doing. Yeah, it's great. There's no water there on the floor, so you can live a little bit better, but you're not getting to the cause. Right. You need to fix the leak in the roof and then actually you no longer need the buckets.
Dr. Robert Lustig
Right. And the problem is, if you don't fix the leak in the roof, you won't have a house.
Rangan Chatterjee
Yeah, that was one of my favorite parts of the book, of these eight processes that are occurring in all of us. And they're either promoting health and longevity, or they're actually the opposite and creating illness and ultimately disease. And I really love the way you say that. Actually. Medicines aren't really tackling those things. And I just want to be really clear for people that antihypertensives or, you know, drugs in general, they have a role sometimes. Right. They can be helpful in certain situations. I think you're in agreement with that. It's just.
Dr. Robert Lustig
I'm not.
Rangan Chatterjee
We over.
Dr. Robert Lustig
I'm not against them.
Rangan Chatterjee
Yeah, okay.
Dr. Robert Lustig
I'm not against them per se. But the problem is that if you don't fix the underlying problem. What have you done? Okay, so it's fine to give a statin to Lower an ldl. But what have you done? Have you actually fixed the problem? You haven't done a damn thing about the problem. The problem's still there. Okay, so you know the very first, the very first sentence of the book, okay, starts like this. You find a wasp in your attic. What do you do? Kill the wasp or find the wasp's nest? You have to work upstream of a problem to solve a problem. Working downstream of a problem only fixes the result of the problem. The problem's still there. And if you don't, if you can kill the wasp, but then the next time you go up into the attic, you're going to be stung into submission by all the other wasps because you didn't fix the problem.
Rangan Chatterjee
I think we really need to, I want to make sure everyone listening and watching this has got this, that what you're talking about is really at the heart of pretty much every single chronic disease that's going on at the moment that is afflicting families. It's overwhelming healthcare systems, it's causing disability, it's causing reduction in the quality of life. And actually most of them are caused by malfunction in these eight areas. But ultimately what you're doing, making a very strong case for is that it's actually the modern food environment. This highly ultra processed food that we are consuming in inordinate quantities is actually at the root cause. And unless we deal with that as a root cause, we're going to be struggling, people are going to be suffering, healthcare systems are going to be suffering, and we're not going to get anywhere. Your intro to the book was, it literally was so punchy. Like we could just do a podcast on the introduction, frankly. But there's a couple of bits I've underlined which, if you don't mind me reading it back to you, your own book.
Dr. Robert Lustig
I so appreciate that you called my intro punchy because several people on Amazon have said all he did was rant. But I guess it depends on how concerned you are about the problem.
Rangan Chatterjee
Yeah, and this is such a big problem. Like it's arguably the biggest problem that's going on across the globe at the moment because, well, let's do it. And you see it in your kids, right? You see kids, I see kids. And when you see a 7 year old with prediabetes, you're like, this wasn't happening 25 years ago. Something is going on. We can't just give them metformin or we have to try and figure out what's causing this.
Dr. Robert Lustig
Canaries. If kids Are the canaries in the coal mine. And if you ignore it, you do it at your own risk. It's just that simple. And that's what we're doing. We've done. We've ignored it. The other thing is that everybody right now is completely distracted, okay? They're distracted by this thing called Covid. Okay? And I understand why. And, you know, it's just. It's certainly distracting. However, let's talk about that for a minute, okay? People are dying in droves in every country. Uk, us, you know, you name it. Do you know where they're not dying? They're not dying in countries that actually still have real food. Third world countries actually have a very low death rate. It's not because they're using masks or hand washing or social distancing. The reason is because they're eating real food. We have the data on mortality rates of the different countries. I can put it up on the screen if you want. But the bottom line is it's only the developed countries that have the high mortality rates. Now why is that? We've identified the elderly and they have immune dysfunction. We understand that they can't generate the same cytokine response that everyone else should be able to. Let's put the elderly aside for a moment because that's true everywhere. That's true in Italy too. But the other three things, the other three demographics that were shown to be related to Covid mortality here they are people of color, the obese and pre existing conditions. Those three people of color, the obese, pre existing conditions. What do those three demographics share in common?
Rangan Chatterjee
Probably poor socioeconomic conditions, poor diet, lost highly processed food.
Dr. Robert Lustig
Right. Ultra processed food consumption, crappy diet, ultra processed food consumption. So why should your food make a difference as to whether you die from COVID or not? Why is that? Here's why. Three reasons. Number one, the virus is very smart. It wants to attack all your cells. And every cell in your body has a receptor that helps regulate water within the cell. That receptor is called ACE2. ACE2? Angiotensin converting enzyme 2. It's an endocrine receptor. That's where angiotensin works and it involves water transport. Every cell has. It turns out the virus uses that protein as its injector point. Well, High insulin increases ACE2 because high insulin causes water retention. There are more ACE2s on all your cells, so you are more at risk of being infected when your insulin is high and your insulin is high because of processed food. That's one. Number two, diabetes, high blood glucose, high Blood glucose. Turns out the glucose actually crystallizes around the edges of those ACE2s holding them open, making it even easier for the virus to inject its RNA number three, short chain fatty acids. Short chain fatty acids come from fiber consumption. Of course, ultra processed food is devoid of fiber. Short chain fatty acids suppress the cytokine response. And we now know it's not the virus that kills you, it's your cytokine response that kills you. Because your cytokine response is basically like a nuclear blast that affects even your normal cells. But it's trying to get rid of the foreign invader. But you have to temper it, you have to be able to manage it, you have to be able to pull it back, you have to be able to minimize it. Short chain fatty acids that come from the digestion of fiber in the gut are one of the things that improves that cytokine response. That's why fiber is anti inflammatory and also improves insulin sensitivity. But processed food doesn't have any fiber that's been removed for shelf life. Those three demographics, people of color, the obese, pre existing conditions, big ultra processed food consumers. High sugar, low fiber processed food, not real food. The CDC and the NIH and the MRC and everyone and public health England, no one is talking about food in Covid. This is the fourth leg of the stool. We all talked about masking and hand washing and social distancing, garbage fix the food.
Rangan Chatterjee
Now I think when we're talking about foods, I think we need to get clear on terminology for people who are listening and they think, okay look, I get this. Highly processed food is at the root cause of many of these chronic diseases. Over half of what we're consuming as a country, as a western society are these foods. So I guess we need to really help people understand, you know, what are these foods? There's this part in the introduction where you actually, I've underlined it. You said, what if this slow consumable poison looks like everything else in the store? How do you protect yourself? And that's kind of part of the problem, isn't it? I don't, it's so normalized that I think many people don't really understand anymore. Well, what is a processed food? What is real food? You know, so can you help us try and understand that? Yeah.
Dr. Robert Lustig
One of the first questions we ask in, in clinic, you know, we used to ask is mom. The mom and the kid come in for OBC clinic and we ask the mom, what do you consider food? Do you think Cheetos is food? If you think Cheetos is food, then basically nothing's going to help you. That's the first thing we do, is we disavow them of this concept, of this knowledge. What we did in our clinic to be effective, we actually studied this, we published on it, we validated it as an instrument. What we did was we took all newcomers, all new referrals to our clinic, and we did a teaching breakfast. These kids came in fasting so we could get comorbidity and safety labs. They saw the doctor, they got their blood drawn, they got their physical exam, and then they went to the teaching breakfast. Six kids, six parents around the table, one dietitian. English and Spanish, different times. So that everybody got a teaching breakfast. We got a $100 gift certificate from Trader Joe's every month to basically buy the food for the teaching breakfast. And of course, our dietitian went out and bought the right stuff, not the wrong stuff. She would then narrate, or he would narrate for an hour why these foods were on the table for breakfast and why the stuff they were buying at home was the wrong stuff. We would explain insulin, and we would show them how much sugar was in each of the things that they were getting at home versus what was on the table. And four things had to come out of that. And we actually validated this four points. Four different points that conferred success. Number one, the parent had to see the kid would eat the food. Number two, the parent had to see the parent would eat the food. Number three, the parent had to see other kids would eat the food because they got other kids at home. Number four, we showed them the bill. They had to see they could afford the food. All four, if we got all four boxes ticked, those patients did well. And then there was no going back. This was a training moment. This was a teaching moment. This was a way we could explain to parents and to kids what was going on and model for them so they can see one do one, teach one way, like we always do in medical school. If you tell people what to do, they will not do it. If you show people what to do and they do it, then they'll do it again.
Rangan Chatterjee
Yeah.
Dr. Robert Lustig
And not until.
Rangan Chatterjee
The term real foods. I like it, you use it. But it does get a bit of pushback from certain academics. And I saw one, I think, on Instagram just a couple of weeks ago, very prominent researcher in obesity in the uk, denigrating the term, saying it smacks a privilege. It's, you know. Yeah. All kinds of things about it. And here's the thing, you know. You know, my view, Bob, is that I found it to be very useful with my patients. Of course, if my patients don't like it, I'd come up with something else that they understand. But generally speaking, I think the things like, you know, would your grandparents recognize it as foods? I think people find it quite helpful. Or does the food packet have more than five ingredients on it or not? As a kind of general rough rule, they're not perfect, but they're all kind of guidelines to try and help people make sense of this ultra processed food environment in which they're living. And I kind of. I wonder why there's so much criticism. It's like these things are there to help people. If you find it helpful, great. If you don't, fine, use something else. But I don't like. I find a lot of people, particularly in medicine and academia, look down on these kind of what are considered simplistic terms.
Dr. Robert Lustig
Yeah, I've heard those complaints also before and I've heard about the smacks of privilege also. Basically what we're saying is real food is food that came out of the ground or animals that ate the food that came out of the ground. That's real food. As soon as a human touched it, now it's processed. Just a question of the degree of processing. Also I'm sure you're familiar with Carlos Montero at University of Sao Paulo developed this system called the Nova System for the degree of processing, which I actually think is the right way to go. Because it's not what's in the food, it's what's been done to the food that matters. All food is inherently good. It's what we do to the food that's not. That's the point I try to make in the book, and I have an entire section on what we did to the food that actually turned it from food into poison.
Rangan Chatterjee
That classification system is brilliant. And perhaps you could take a kind of readily available, simple food and just explain how it can go through these four stages to help people really understand this.
Dr. Robert Lustig
Sure, I can do this in one minute. Let's take an apple. Class one on the Nova system would be an apple. Class two on the Nova system would be apple slices. Class three on the Nova system would be applesauce unsweetened. Class four on the Nova system would be an apple pie. There you go. Turns out that only the Class 4 foods are associated with chronic disease.
Rangan Chatterjee
So we can have. We can have minimally. That's really. So we can have, you know, minimally processed foods that are done to make our life easier a little bit, or, you know, but it's when it goes to that extreme where it's actually bears no resemblance to actually what actually came out of the ground in the first place.
Dr. Robert Lustig
That's right. And so what is different about that apple pie versus the apple? The answer is the addition of sugar and the removal of fiber. The addition of sugar is what basically floods the liver, because the liver, like alcohol, only has an innate capacity to metabolize a small amount. We know how much sugar we can metabolize. It's not that different from the amount of alcohol that we can metabolize because the metabolism is virtually the same. Point is, you can overwhelm your liver's capacity to metabolize sugar. When that happens, just like what happens when you over metabolize alcohol, is your liver can handle the onslaught, and so it has to take the extra and turn it into fat. There are enzymes in your liver that turn sugar into fat. It's called de novo lipogenesis, new fat making. There are three enzymes that in concert that do. This one's called ATP citrate lyase. The other one's called acetyl coa carboxylase, and the last one's called fatty acid synthase. These three enzymes are being driven by excess substrate, and that substrate is fructose, then turned into acetyl coa by glycolysis. So bottom line, you're flooding your liver, and the goal is protect the liver. When you flood your liver now, your liver makes fat, and that fat precipitates. Now you got fatty liver, and now you got insulin resistance, and now you got chronic metabolic disease. So protect the liver. Second part, feed the gut. Everyone now knows that the microbiome talks to your brain, which is true, it does. So feed the gut. That's what a prebiotic does. So what's a prebiotic? A prebiotic is food for those bacteria that will feed them so that they can grow. And what's the nature's perfect prebiotic?
Rangan Chatterjee
Fiber.
Dr. Robert Lustig
Fiber. Fiber is not food for you. Fiber is food for your bacteria. But when we took the fiber out of the food to process it, because fiber basically reduces shelf life, when we took the fiber out of the food to process it, we are now depriving our bacteria of the food they need to be able to live in symbiosis with us. Those bacteria, the good bacteria are dead. The bad bacteria have taken over. And the bad bacteria sending all sorts of bad signals actually suppressing serotonin generation in the intestine, thereby reducing the anterograde transport of serotonin back up into the nucleus tractus solitarius. And that's called depression. Also because you're not feeding those bacteria, the bacteria are basically stripping the mucin layer right off your intestinal epithelial cells because they can eat that. And that's then exposing and denuding your intestine and making it all the junk that's in your intestine basically can get through called leaky gut, contributing to inflammation, inflammatory bowel disease, irritable bowel syndrome and insulin resistance, all because you didn't feed your gut, you didn't microbiome.
Rangan Chatterjee
And that's how the whole thing gets tied together here. That some very simple but very, very brilliant advice. Protect the liver, feed the gut. But the modern food environment, the ultra processing of food is overwhelming the liver with sugar and it's starving the gut through its lack of fiber. And then the consequences are the liver could be fatty liver, type 2 diabetes. But the problem when the gut gets starved and as you say leaky gut or increased intestinal permeability sets in, then you're opening up for everything. Autoimmune disease, food allergies, Alzheimer's, depression, all these things have been associated with increased permeability in the gut. So it's a very simple maxim, but one that actually again going to that nexus of the root cause, it's kind of right there, isn't it? And that's, you know, this is the other thing I really liked, Rob, is that you don't seem to have a preferred diet very much like me, I'm always like you, it's unprocessed. The diet first. Let's just get out the chunk, let's get the real food in and then let's see where we are. So how does you feel that like a vegan diet or a low carb diet or a whole manner of diets can fit this maxim of protecting the liver and feeding the guts?
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Dr. Robert Lustig
Yeah, I'm agnostic as to the whole vegan keto thing. Look, people who want to be vegan, fine, whatever. You want to be vegan, great. Don't make anybody else feel bad about their choice, but you know, you can feel good about your choice, that's fine, okay? There are a lot of reasons to be vegan. You know, animal welfare, religion, cost, coolness, if you will, but metabolic health is not one of them, okay? And I can prove it, because Coke, Doritos and Oreos are all vegan. So you can do vegan right or you can do vegan wrong. Keto, okay? I'm not against keto. I used ketogenic diets in my patients when their insulin resistance was so severe that nothing else would work, where they had insulin hyper secretion and basically we had to control their blood glucose rises in an attempt to try to stave off continued weight gain. Either one. So we use the ketogenic diet, okay? And I'm not against that. The problem with the ketogenic diet is not the diet. The problem with the diet is that it's really easy to fall off it, because as soon as you have even a little bit of carbohydrate, a little bit of carbohydrate is going to raise your blood glucose, therefore raise your blood insulin, and therefore stop the ketogenesis, because insulin blocks lipolysis at the level of the fat cell and there goes your lack of substrate. It's been shown that people who are left to their own devices in terms of doing a ketogenic diet. They can start with all good intentions and by two months into it, they're basically, they're not in ketogenic anymore. They're not making ketones, basically. And then they're on the worst diet because they're on a high fat, medium carbohydrate diet, which generates both insulin and loads and loads of ldl. That's kind of like the worst thing you can be on. So if you're fastidious, then the ketogenic diet is a great diet. If you're not fastidious, then you shouldn't be on a ketogenic diet. So it kind of depends on whether or not you can actually keep it up. And a lot of people fall prey to the croissants on the that the other guy at work brought in. So bottom line is I don't have a preferred diet. I'm agnostic on it. I think there are a lot of ways to skin this cat. I think ultimately we will learn the genetics of who does better with which diet, and it will turn out that certain diets are better for certain people and other diets are better for other people. And I'm very interested involved in this personalized nutrition concept and movement that's going on right now. So it may be that there are certain people out there who are on a vegan diet who ought to be on keto, and there are certain people who are on a ketogenic diet who probably ought to be in a vegan one and they don't know it yet. Why would you basically put all your marbles in one goldfish bowl? So I'm for both diets. The only diet I'm not for is the western diet.
Rangan Chatterjee
And the reality is, I think any clinician who has utilized food as one of their tools in their toolbox with their patients, which I hope more and more are starting to do, although it's. That's clearly not enough. You will see that different people thrive on different diets. That's, you know, I think real life clinical practice teaches you that. Well, these guys here are literally rocking a low carb, real food diet. Their markers look good, their bloods look great, and all these people here are doing great on a whole food vegan diets, as you say, the commonality is no processed food or very, very low amount of ultra processed foods.
Dr. Robert Lustig
The commonality is low sugar, high fiber. Both diets work when they're low sugar, high fiber. And so that's why I Think those are the two sort of linchpins in this whole story. But unfortunately, that's exactly what processed food is not.
Rangan Chatterjee
You used apples before to demonstrate those four categories of processing, which I thought was really nice Example. Where would apple juice fit into that? Because that's something that many people are consuming every day thinking it's healthy. Hopefully, they might be reevaluating that at the end of this conversation. But, yeah, where does that fit in?
Dr. Robert Lustig
So what happens with apple juice, whether it's, let's just take apple juice that's not also sweetened, because sometimes they add extra sugar. Just taking an apple and putting it in the Vitamix, let's do that kind of apple juice. Apple juice that's been Vitamix or the Jamba Juice. People say that's great, right? Because that's whole fruit. Well, it was whole fruit. Now it's not. So you have to understand the problem of fiber. Now, fiber, we've been talking about it like it's one thing and that's not correct. Fiber is two things. One's called soluble fiber. And an example of that would be like inulin or pectin is like what holds jelly together, Hydrogel. So it's in cream cheese. And then there's a second fiber called insoluble fiber, and that's like cellulose. That's like the stringy stuff in celery. It's also what's in cardboard. Okay, so cream cheese, cardboard. Okay. Both fiber. Ha ha.
Rangan Chatterjee
All right.
Dr. Robert Lustig
Well, it turns out that real food has both. Now, when you put the apple in the Vitamix, you are shearing the insoluble fiber, the cellulose, to smithereens. You're cutting it up into such little, small, little fragments that it's not going to be functional afterward. Here's how the soluble and insoluble fiber work together. Imagine a fishnet plastic matrix with holes in it. When the fishnet is working, what happens is you can catch fish, but then the kelp, the seaweed, is going to plug the holes in the fishnet. And now you're not going to be able to drag it through and catch the fish anymore. So you've created a barrier so that the insoluble fiber is like the fish net itself, and the soluble fiber is like the kelp. Together, they form a barrier. Or think of it this way, like a spaghetti colander, metal bowl with holes in it, right? You run the water, water runs through. Now, take a blob of petroleum jelly, throw it into the center of the colander run the water still runs through. Now take your finger and rub the petroleum jelly all around the inside of the colander. Now run the water. Now the water doesn't run through. You've created a barrier, and you needed three things. You needed the colander, you needed the jelly, and lastly, you needed the geometry of plugging all those holes for the fishnet. You needed the net and you needed the kelp together. If somebody came along and took a scissor to that fishnet, all of a sudden, now you don't have a barrier anymore. This is what's going on in your gut. The insoluble fiber, the cellulose, the stringy stuff in the celery, is forming a lattice work on the inside of your intestine. The soluble fiber, like the pectins and inulin, they're globular. They're plugging the holes in that lattice work together, they form a whitish gel on the inside of your intestine. That gel is a secondary barrier that prevents early absorption of glucose, fructose, sucrose, simple starches, so that they don't end up going to the liver, they don't flood the liver so that your liver doesn't turn them into fat, so that your liver can stay healthy. So the apple juice, the Vitamix apple juice, it still has the soluble fiber and that still has a benefit because that can still go down to your colon and make short chain fatty acids. And that's good, but it won't protect your liver. You've taken one of the two cardinal phenomena of health and you've basically thrown it in the garbage can. Apple juice, better than soda because it has soluble fiber, but not better than soda because it floods your liver.
Rangan Chatterjee
But soda presumably also floods your liver huge. Well, of course, yeah. And what's the relationship? Obviously, we're now moving from food into, I guess, drinks, although apple juice, of course, comes from an apple. Soft drinks, diet drinks, these are things which are routinely consumed. Perhaps you could talk about the relationship between these drinks and our wider health.
Dr. Robert Lustig
Right. So first of all, it's now been shown 50 ways from Sunday that sweetened beverages, sugar sweetened beverages, soft drinks are disastrous. They're disastrous for adults, they're disastrous for kids. We have quantitation on just how many deaths per year occur in both the US and the UK due to soft drinks alone. This has been done by numerous investigators, most notably the ones at Tufts Friedman, like Darius Mozaffari and his group, Renato, Mika, et cetera.
Rangan Chatterjee
No question.
Dr. Robert Lustig
So then you say okay, that's true. But what about diet drinks? They have no fructose, they have no calories. They should work. They should be fine, right? Not so much. So here's why. A couple of studies have now shown exactly why. A couple of years ago, I wouldn't have been able to tell you this, but now we have the data that explains why. This is number one. You put something sweet on the tongue, message goes tongue to brain, sugar's coming. Message goes brain to pancreas, sugar's coming, Release the insulin. But then the sugar never comes because it was a diet sweetener. What does the pancreas do? Does it say, oh, man, I was waiting for that. I'll just wait till tomorrow? Or does it go, you know, I got all these insulin vesicles sitting here raring to go. Okay, I'm going to go find me some calories to work on. You end up overeating. Turns out it's the latter. We now have the data to show us the latter. In fact, all the studies of diet drinks show that total caloric intake does not change. You think you're doing well by taking 150 calories in sugar out of your diet, but it turns out you end up making up those 150 calories elsewhere in your diet. It's been shown in different experimental conditions that basically it sensitizes your pancreas to actually make more insulin. Most diet drinks, this was work from Janina Pipino when she worked with Sam klein at Washoe St. Louis, and also Tay et al, that showed that if you consume diet sweeteners instead of sucrose, you will not consume as much many calories in the morning because the diet soda that you drank in the morning, but you will actually increase your food intake later on in the afternoon and evening so that the total number of calories you ate ends up being exactly the same. Which is why diet drinks have not caused anybody to lose weight, because you end up making it up later. That's number one. Number two, we now know that certain diet sweeteners actually alter the microbiome in a negative fashion and contribute to leaky gut, the most famous of which is sucralose or Splenda. Worse yet, we now know that adipocytes, fat cells, have receptors for diet sweeteners. If you absorb those diet sweeteners, they go through your bloodstream, end up at your fat cell. They can cause fat deposition in the fat, irrespective of insulin. So the bottom line is, diet sweeteners might trick your tongue, but they don't trick your body.
Rangan Chatterjee
Yeah. And it kind of sort of makes sense, doesn't it? If we go back to the fact that our biology, we've been wired over hundreds of thousands of years to respond a certain way to certain things in our environment, and we've just changed that so much. And did artificial sweetness exist 100 years ago? 150 years ago. Has our biology learned how to adapt? Of course, it doesn't mean we can't learn, but I know it's a very controversial area. But my advice with my patients has always been, look, I'd be really cautious with this. I don't think you should go to that. I'd much prefer water or something else. But I've always taken that more precautionary principle. I know many people vocal on social media will say that there's no problem with artificial sweeteners, but you think it's pretty clear now with artificial sweeteners?
Dr. Robert Lustig
Yeah, I think the data are in. There was a paper that came out in the American Journal of clinical nutrition about 2017. What they did was they showed, we're using a meta analysis, that the toxicity of one Coca Cola equals the toxicity of two diet Coca Colas. Half as bad. That doesn't mean good. That means half as bad. Now, the problem is, okay, it's half as bad, but people who are drinking diet soda say, oh, no fructose, no calories. I'll drink five of them. Now it's two and a half times as bad.
Rangan Chatterjee
We've mentioned sugar as a mitochondrial poison. We've mentioned insulin resistance as a root cause of many of these chronic diseases. And we mentioned obesity and weight gain as a symptom rather than the cause. What we haven't quite mentioned yet is thin people who think they're okay because they don't look overweight. Yet on the inside, there's a very different story. And I wonder if I could just frame that around the statistic, which I've heard before. You've written about it in your book, that 88 of Americans have a degree of metabolic dysfunction. But I also love the way that you describe metabolic syndrome. The. You know, maybe you could describe how you say it. I think it's a beautiful, beautifully simplistic way of looking at it and then put it in the context of that thin person who thinks they're doing okay.
Dr. Robert Lustig
So here's the problem. Everybody thinks that the scale tells the truth. The scale tells you how much you weigh. Who cares? Seriously, who cares? And here's why the scale lies, because there's not one fat depot. There are three, three separate fat depots and they contribute differentially to your health. Here they are. First one, the one you can see, the subcutaneous fat, the big butt fat, as it were. As in, do these genes make me look fat and never answer that question? Bad idea. Turns out the subcutaneous fat, while potentially cosmetically undesirable, is metabolically inert. Our subcutaneous fat is there very specifically to store energy for periods of famine. It has an innate expansive capacity to a certain point before it gets into trouble. In fact, you can basically put on about 10 kilos of subcutaneous fat, about 22 pounds of subcutaneous fat before you will have over expanded those cells. Those cells will then have choked off and died, will have released their grease into the area, will have recruited macrophages in to clean up the grease, and will then have released cytokines into the bloodstream, which will, by the way, go into the systemic circulation. You have to have a lot of grease in order to get a concentration high enough to go back to the liver to activate the cytokine response in the liver and cause insulin resistance. 10 kilos of subcutaneous fat before you get sick, that's depot number one. Depot number two, the visceral fat, the belly fat, the beer belly, if you will, fat. Now, that fat turns out not to be from beer. That fat turns out to be from stress. From stress. You know a lot about stress. That fat in your belly fat, visceral fat is due to cortisol. And cortisol is because our world is now overly stressful and people are overly stressed all the time. So how do we know that? The answer is because we can take patients with clinical depression, endogenous clinical depression, suicidal depression, get admitted to the hospital to keep them from themselves, put them in a scanner and quantitate the amount of visceral fat. Now they're losing weight because they're not eating. They're losing subcu fat because they're not eating. But they're gaining visceral fat because their cortisol is so high. That is metabolically active fat. It drains directly into the liver because it drains into the portal vein, not into the systemic circulation. A small amount of visceral fat will generate enough cytokines for your liver to be able to see it because it's concentrated, because it's not being diluted over the entire volume of distribution of your systemic circulation. Turns out about 5 to 6 pounds of visceral fat before your liver gets sick. For sub Q fat. 22 pounds for visceral fat. 5 to 6 pounds. Now can you see 5 to 6 pounds on the scale? Maybe, maybe not. Now let's do the third fat depot, the liver fat. The fat in your liver turns out to be the most egregious because it's right there. It's causing the problem right where the action is right there in your liver. It turns out only a half a pound of visceral fat, liver fat. Half a pound of liver fat and you will end up with metabolic dysfunction, insulin resistance. Can you see a half a pound on the scale? No. So three different fat depots. So the question is, what makes the liver fat? Answer. Sugar. Because of this phenomenon, the de novo lipogenesis that we've been talking about, you are mainlining it right into the organ that is the most susceptible to the problem. And you can't even see it on the scale. There are people walking around with fatty liver and don't know it because they say, well, I'm thin, no problem. Except they have a problem. That's why 88% of Americans now have some form of metabolic dysfunction, because either sugar or alcohol is causing liver fat, irrespective of what it's doing the rest of your body.
Rangan Chatterjee
Yeah.
Dr. Robert Lustig
And they don't know it. That's the nugget of truth that people, you know, that doctors are ignoring.
Rangan Chatterjee
Of course, that begs the question, how can people find that out? I will say, because we don't have much long left. I don't want to be respectful of your time that in your book, there is a whole section on the various blood tests that you should go and get. They're very simple and actually very readily available. And actually that abuse section on, you know, what the actual values are, but also what's optimal, what we should really be gunning for. Obviously there's things like DEXA scans, there's waist to hip ratios that people can do. But I guess, you know, from. In my culture, a lot of people from my ethnicity are walking around. It's quite. It was almost a joke growing up. Like, you'd see dads not a joke, but you'd see, you know, dad's friends after they hit a certain age, it'd still be thin everywhere, but the belly would just start to go out. But. But thin arms, thin legs, just that belly. And of course, you know, many South Asians do have an increased risk of tofi. Thin on the outside, fat on the inside and all those sort of things. But I really wanted to highlight this because I think many of us think, oh, it's all right for them, they can eat whatever they want and they don't put on weight. It's like, well, wait a minute. Yeah, cosmetically they may not be looking. They may look as though they're getting away with it, but they may not be. I also just want to finish off on kids. You just mentioned liver fats. I've heard you say before that you've had to send two children at least for liver transplants, because that is absolutely alarming. Rob from soda drinking. So maybe before we get to the final point, I just wonder if you could. There's many parents who listen to this podcast and of course a lot of people can take the advice for themselves. Right. I need to have a low sugar diet, I need to have high fiber, whatever my preferences are. But with kids, it seems to be quite different. Kids meals are a joke in most places. It's like the adults can have proper food and the kids have the junk in bars and restaurants. Right. It's the same in the us.
Dr. Robert Lustig
Chicken nuggets and french fries and a Coke.
Rangan Chatterjee
So what is it doing to kids at this early age when they're having regular juices, regular soda drinks, regular highly processed foods? It's not really necessarily about their weight, is it? It's about, is it setting the tone for later on in life? And then what advice would you give to parents?
Dr. Robert Lustig
First of all, sugar downregulates its own receptor on the tongue. So the more sugar, the less sweet. Therefore, you need more sugar. So it becomes a vicious cycle. That's one thing. Second of all, it still causes liver fat accumulation in kids. We now have shown that 20% of children have liver fat unrelated to obesity. Kids who have died in auto accidents. Autopsies show 20% of kids have liver fat unrelated to obesity. Where did they get liver fat from? They never had it before. This is where the bottom line is that this phenomenon is also. The sugar is also causing changes in behavior. Now, we don't have enough time to go into this, but sugar inhibits an enzyme in the brain in astrocytes called glutamine synthetase. Glutamine synthetase is necessary to turn glutamate into glutamine, which then will go to gaba. GABA is the inhibitory neurotransmitter. Glutamate is the excitatory neurotransmitter. There's a balance between excitation and ambition. And sugar basically breaks that balance. Sugar has been associated with irritability. It's been associated with violent behavior. It's been associated with cognition problems. It's been associated with dementia in adults. It's been associated with changes in the prefrontal cortex thickness. It's been associated with. Associated with problems in school. It's been associated with all sorts of problems. Now, associations, not causation. We are still working on putting all the causation pieces together. So I'm not here to tell you that sugar's poisoning your brain yet, but there's a lot of data, and the data in animals is pretty darn good. You really want to go this route, people.
Rangan Chatterjee
And you're not talking about just white table sugar. You're talking about the processed foods. You're talking about the fruit juices, right?
Dr. Robert Lustig
Absolutely. I'm talking about the Capri Suns. I'm talking about the stuff that the parents are putting in the lunchbox.
Rangan Chatterjee
Yeah. And that statistic, 20% of kids have liver fat. There could be parents listening to this who think my kids look fine weight wise. So what's the problem with a glass of apple juice a day? That's the problem. Yeah, exactly. And so this conversation is not meant to shame anyone. It's just meant to try and raise awareness as something that we both feel could be really, really helpful. Rob, I've got to say that if people want more, and I hope they do well at some point, if we can get a second conversation, I'd love that. But the book Metabolical is. It's really thorough, it's really comprehensive. I really would recommend people who want to learn more about this to get a copy. I think it's something you can keep dipping back in and out of over time. I really do think it's a fantastic read and you cover the planet as well in it, which we didn't get a chance to talk about today. Just to finish off. This podcast is called Feel Better, Live More. When we feel better in ourselves, we get more out of our lives. And if you have everything you've said, if you have all your passion about this area, I just wonder if you could just leave my audience with some of your final thoughts and a few top tips that they can think about applying into their lives.
Dr. Robert Lustig
The most important thing people have to understand is, and you say it yourself, I'm basically trumpeting what you say. To solve a problem, you have to solve the cause of the problem, not the result of the problem. Doctors don't know how to do that, and I can say that because I'm one of them. I didn't understand that going through medical school And I didn't understand that. For the first 20 years of my practice, I did what I was told. I practiced the way they taught me to do. I got woke. You got woke. There are doctors around now who are getting woke up and they're starting to make some, shall we say, noise. They're being cast off as heretics and rabble rousers and troublemakers and whatever. And some of them have even gone on trial in their respective countries. Tim Noakes in South Africa, Carrie Fetke in Australia, Evelyn Bordeaux Roy in Canada. Don't know if there are any in the UK that have had that happen. But the bottom line is we are undergoing a revolution in modern medicine. We underwent a revolution back in the 1930s, 40s with antibiotics where we thought a pill could treat everything. Now we're undergoing a revolution where we realized that was a mistake. It's time to rethink health. It's time to rethink health care. You can't fix health care till you fix health. You can't fix health until you fix diet. And you can't fix diet until you know what the hell is wrong. And what you thought was wrong was basically propaganda. For the last 50 years, we've had to undo that. We've had to basically turn it over. We've had to rethink all of modern medicine. And the. For your audience out there, what I'm telling you is not everything is wrong, but a lot of it is. When I went to medical school in 1976, a very, very famous clinician stood up in front of our class on the very first day. And you've probably heard this yourself, rangan, he said 50% of everything we teach you is wrong. We just don't know which 50%. This is the 50%.
Rangan Chatterjee
Robert Lustig, you have been doing incredible advocacy for many, many years. You continue to do it. You're helping the lives of hundreds of thousands of people, if not millions around the world. Thank you for joining us on the podcast and hopefully we'll get a chance to talk again in the future.
Dr. Robert Lustig
It's my pleasure, hope to come to the UK and we'll have a beer. Just one.
Rangan Chatterjee
Really hope you enjoyed that conversation.
Do think about one thing that you.
Can take away and apply into your own life.
And also have a think about one thing from this conversation that you can.
Teach to somebody else. Remember, when you teach someone, it not only helps them, it also helps you.
Learn and retain the information.
Now, before you go, just wanted to let you know about Friday 5. It's my free weekly email containing five simple ideas to improve your health and happiness. In that email, I share exclusive insights that I do not share anywhere else, including health advice, how to manage your time better, interesting articles or videos that I've been consuming, and quotes that have caused me to stop and reflect. And I have to say, in a world of endless emails, it really is delightful that many of you tell me it is one of the only weekly emails that you actively look forward to receiving. So if that sounds like something you would like to receive each and every Friday, you can sign up for free@drchatterjee.com Friday 5 Now if you are new to my podcast, you may be interested to know that I have written five books that have been bestsellers all over the world covering all kinds of different topics. Happiness, food, stress, sleep, behavior change and movement, weight loss and so much more. So please do take a moment to check them out. They are all available as paperbacks, ebooks and as audiobooks which I am narrating. If you enjoyed today's episode, it is always appreciated if you can take a moment to share the podcast with your friends and family or leave a review on Apple Podcasts. Thank you so much for listening. Have a wonderful week. And please note that if you want to listen to this show without any adverts at all, that option is now available for a small monthly fee on Apple and on Android. All you have to do is click the link in the episode notes in your podcast Apple and always remember, you are the architect of your own health. Making lifestyle change is always worth it because when you feel better, you live more.
Episode #616 (Re-release): The Bitter Truth About Sugar with Dr Robert Lustig
Date: January 25, 2026
This compelling conversation features Dr. Robert Lustig, Professor of Pediatric Endocrinology at the University of California and leading public health advocate, who is internationally recognized for his work on sugar, processed food, and metabolic disease. In this wide-ranging and passionate episode, Dr. Lustig and Dr. Chatterjee dissect the root causes of chronic illness, the ways in which "ultra-processed food" and sugar upend health, and why focusing on real food is vital to combating today’s disease epidemics. Dr. Lustig’s decades of clinical and research experience, and the striking slogans and metaphors he uses, make this not only an eye-opening but also an empowering and practical episode for listeners.
[00:00–07:52]
Notable Quote:
"Sugar is a particularly egregious molecule. Once upon a time, trans fats were the worst... Now sugar is public enemy number one."
— Dr. Robert Lustig [04:13]
[07:52–11:41]
[12:51–16:25]
[16:25–21:22]
Notable Analogy:
"The problem with sugar in the liver is exactly the same as the problem of alcohol in the liver."
— Dr. Robert Lustig [17:40–21:00]
[22:15–41:10]
Notable Quote:
“It’s all a scam. The whole thing’s a put-up job.”
— Dr. Robert Lustig [41:08]
[43:45–49:24]
[51:52–66:25]
Memorable Maxim:
"Protect the liver. Feed the gut."
— Dr. Robert Lustig [68:48]
[74:00–78:50]
[79:12–89:19]
Notable Quote:
“Diet sweeteners might trick your tongue, but they don’t trick your body.”
— Dr. Robert Lustig [88:24]
[90:03–96:54]
[98:56–101:44]
[103:02–105:44]
In this eye-opening and thorough discussion, Dr. Robert Lustig makes a passionate, science-backed case for shifting away from treating symptoms and toward addressing the dietary root causes of chronic disease. He advocates first principles: eat real food, avoid sugar and ultra-processed foods, and focus on supporting liver and gut health. The episode is rich with metaphors, clinical anecdotes, and clear explanations—providing both a diagnosis of what has gone wrong and practical steps for individuals and society to take.
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Compiled by: [Your Podcast Summarizer]
(Original language and tone preserved; timestamps provided for key segments and quotes.)