MS. DIANE REHMThanks for joining us. I'm Diane Rehm. A new study indicates overweight people have less of a risk of dying compared to people who are not overweight, but the risks of chronic disease are real. In a new book, Dr. Robert Lustig explains the pernicious role of sugar in our diets, and its devastating effects on our body biochemistry. His book is titled "Fat Chance." Dr. Robert Lustig joins me to talk about beating the odds against sugar, processed food, obesity, and disease.

MS. DIANE REHMI hope you'll join us. 800-433-8850. Send us your email to drshow@wamu.org, feel free to follow us on Facebook, or send us a tweet. Good morning to you, sir. Thanks for being here.

DR. ROBERT LUSTIGOh, it's my pleasure, Diane. Thank you for having me.

REHMIndeed. You argue in your book, "Fat Chance," that it's metabolic function and not just fat that really matters when it comes to your health. Explain what you mean.

LUSTIGThat's exactly right. As far as I'm concerned, weight is not the issue. Twenty percent of obese people have completely normal metabolic function. They will live a completely normal, healthy, productive life, will die at a normal age, the only thing is they're obese. Conversely, up to 40 percent of normal weight people have the exact same diseases that the obese do, heart disease, lipid problems, stroke, hypertension, cancer, dementia. They're just not obese.

LUSTIGThe point is, it's the metabolic dysfunction that causes these diseases that we really need to worry about. So obesity is a marker for this metabolic dysfunction, but it is not the cause.

REHMSo what is it within us that regulates metabolic function?

LUSTIGIt has to do with an area of the cell called the mitochondria. The mitochondria is the little energy-burning factory inside the cell, and the question is, what gets brought to the mitochondria, what the mitochondria do with that energy, what does it do with any excess, does it turn it into something that's useful like something called ATP, which is necessary for life and helps your burn, or is it going to be turned into fat?

LUSTIGAnd if it's turned into fat, it doesn't matter whether it was dietary fat to start with, or whether it's sugar in the case of most people in this country, or branch chain amino acids, , which you find in corn-fed beef, or for that matter, alcohol. These are all substances that go to the mitochondria, don't have a pop-off valve to something that's safe and get turned into liver fat and cause disease. So it's not just sugar, although sugar is the big kahuna in the story, and it's the thing that has been glutted in our current food supply.

REHMNow, do most doctors test for metabolic function?

LUSTIGOf course not. And there -- it's actually kind of difficult to do that. There are certain lab tests that can do that. The best way to determine whether or not you've got metabolic dysfunction or not is your waist circumference, not your weight. I tell people, the scale lies more than you do. When you stand on the scale, you're measuring four compartments at once. Bone, more is better. Muscle, more is better. Subcutaneous fat, big butt fat, if you will, turns out more is better.

LUSTIGSixteen thousand Dutch men one slice CT through the abdomen, it turns out, more subcutaneous fat, more better. And that is why the paper that came out in (word?) last week that says a little overweight is okay, is actually correct, because it's subcutaneous fat.

REHMYeah. But how do you measure a little...

LUSTIGThat's right.

REHM...versus a little more?

LUSTIGThat's where you need a doctor. And the fourth compartment is the visceral, or the big belly fat. So, as far as I'm concerned, it's not about weight, it's about waist. Measuring waist circumference is probably the single-best thing you can do for yourself. It's cheap, and when you exercise, you don't lose weight, you actually gain weight because you're gaining muscle. But what you're doing is, you're making mitochondria, and you're losing that visceral fat, and that's why exercise improves health, not because of weight loss.

REHMSo what you're saying is that that waist size needs to be somewhere in proportion to the rest of your body for you to be considered healthy metabolically?

LUSTIGRight. And it is irrelevant to what your actual weight is.

REHMThat seems rather farfetched.

LUSTIGWell...

REHMI have to -- I have to say to you, because I have seen many overweight people with lovely shapes.

LUSTIGYes. Absolutely. And do you know what their metabolic status is? It's probably pretty good. There's an imager by the name of Dr. Jimmy Bell at University College, London, and he coined the term TOFI, T-O-F-I. Thin on the outside, fat on the inside. What he does is he actually does -- slices all the through -- MRIs all the way through your body and quantitates the amount of fat that's not just in your love handles, not just in your subcutaneous space, but actually looks at what's in your organs. And it turns out that those 40 percent of people who have metabolic dysfunction, they're TOFIs, and they don't know it.

REHMOkay. So if you went to your own doctor and said, I want a real readout on my metabolic function, what would that entail?

LUSTIGIt's relatively complex, kind of hard to explain, you know, in a lay format, but let me just sort of give you what we do in say my clinic. What we're first of all interested in is not just BMI, but we're interested in BMI Z score, which is a method for turning BMI into something that matters for kids, because our kids are still growing, and, of course, puberty matters a lot as well for this. We look at fasting insulin levels.

LUSTIGNow, right now, the American Diabetes Association does not recommend fasting insulin levels, and the reason is because they don't know what to do with it, but the fact is, we do. The reason is there are two insulin problems, not one. So when you interpret a fasting insulin level, you have to interpret on the basis of what is actually going on with the patient. There's one called insulin resistance, and there's another called insulin hypersecretion. If you're looking for insulin hypersecretion, you have to do a glucose tolerance test which we often do.

LUSTIGWe also do liver function tests like an ALT which tells us about the amount of liver fat. We also do fasting lipid profile, and the last thing we do is a uric acid, because a uric acid is a very good proxy for sugar consumption, and tells us a lot about how the liver is doing. Those are all things that we do in our clinic when evaluating patients for how sick they are relative to their weight.

REHMAll right. So is there a single villain here? Is sugar consumption at the heart of the problem?

LUSTIGSugar consumption is probably the big one. It's not the only one. And sugar does not cause obesity per se. I want to make that very clear, and I make that clear in the book. People say, it can't just be sugar, we're eating all of these other things. We're eating potato chips, we're eating French fries. Mozaffarian at Harvard School of Public Health actually looked at the Nurse's Health Study and said that potato chips and French fries were the biggest contributors to total weight gain. I agree, that's right.

LUSTIGWhat sugar does is, because of the way it is metabolized, it is the thing that pushes obesity over into metabolic syndrome. So lots of things cause obesity. Sugar takes obesity to metabolic syndrome, and metabolic syndrome is what kills you.

REHMAnd what about the difference between sugar and fructose?

LUSTIGWell, fructose is the sweet molecule within sugar. So table sugar, beet sugar, cane sugar, high fructose corn syrup, they're all basically equivalent. They have one molecule of glucose. Now, glucose is the energy of life. Every cell in the body, every cell on the planet can utilize glucose for energy. Every organism can utilize glucose for energy, but it's not particularly sweet. It's not very interesting. You don't see people going around chugging Karo Syrup, do you? Okay? It's not all that exciting.

LUSTIGIt might work in a pecan pie, but that's about it. Fructose is the other molecule in sugar, and fructose is not glucose. Glucose is a six-membered ring. Fructose is a five-membered ring. Fructose breaks apart that five-membered ring and exposes its reactive what's called keto group, which can cause binding to proteins. It's the browning reaction. It's why you slather barbecue sauce on your spare ribs while you're grilling them, and it makes that nice brown color and smells really good and makes you, you know, mouth watering and all that.

LUSTIGWell, that's going on in your arteries as we speak. If you had orange juice this morning, that browning reaction is occurring faster.

REHMReally?

LUSTIGAnd when it's occurring, it's causing hydrogen peroxides to be released, and it's causing those proteins to become less flexible, and that is the aging process right there.

REHMSo you're suggesting for example that to eat the fresh fruit would be better for you than drinking the orange juice?

LUSTIGAbsolutely. Here's why. How many oranges can you eat in a sitting?

REHMWell, I don't eat oranges. I eat pineapple. I eat cantaloupe.

LUSTIGOkay.

REHMI eat watermelon, and I eat honeydew.

LUSTIGAll of which are fine. We actually did an experiment, my colleague Cindy Gershen in Walnut Creek, California, in her food science class. Took two students, gave one student six oranges and said, here, make juice. The kid makes orange juice out of the six oranges, a little over 12 ounces...

REHMRight.

LUSTIG...drinks the whole thing down and says, okay, what's for breakfast.

REHMWhoa.

LUSTIGThe other kid, we say, okay, here are six oranges. Eat the six oranges. By the time the kid gets to orange number four, the kid throws up and says, I couldn't possibly eat another bite. Why? Very simple, it's called fiber. Because the fiber is the thing that mitigates the negative effects of the fructose in fruit. Why? Number one, it delivers more of the nutrient downstream in the intestines so that the bacteria in the intestine can chew it up instead of you. So you don't absorb all of it.

LUSTIGNumber two, it gives you the satiety signal sooner, because it delivers that to the end of the intestine faster, and number three, the fiber forms a barrier on the inside of the intestine, preventing the sugar from being absorbed so fast so your liver has a chance to catch up.

REHMDr. Robert Lustig. His new book is titled "Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity, and Disease."

REHMAnd welcome back. Dr. Robert Lustig is with me. He is pediatric endocrinologist. He's director of the Weight Assessment for Teen and Child Health Program at the University of California San Francisco Children's Hospital. He's the author of "Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity and Disease." You talk about the generally accepted way to lose weight, which is simple eating less. But that's just not all there is to it.

LUSTIGI wish we could eat less. The fact is, there's a system in our body that's keeping us from eating less and being able to do something about it. It's called leptin. Leptin is a hormone that's made in your fat cells, goes to your brain and it's supposed to tell your brain, you know what, I've got enough energy on board to engage in normal expensive metabolic processes like puberty and pregnancy. I have enough energy on board to burn energy at a normal rate and I have enough leptin on board to feel good.

LUSTIGThe problem is, we don't feel good. We think we're starving, and so we eat more. And the reason is because our leptin isn't working. Our research and countless other people's research have been examining the role of what we call leptin resistance. That is the leptin levels are plenty high and they should be telling our brain that everything's fine. But clearly, our brain is not getting the message.

LUSTIGSo leptin resistance is the holy grail of obesity. And what our research and others have shown is that insulin, the hormone insulin, actually blocks the leptin signal at the level of the brain. So when your insulin goes up, your brain can't see the leptin. Your brain thinks you're starving and that causes you to eat more.

REHMSo, what are you going to do if you want to lose weight? You say what you've got to do is exercise.

LUSTIGWell, what you have to do is get the insulin down. You have to get your insulin down any way you can. And there three ways to get insulin down. One is called diet, but not just eat less, because less doesn't work. Eat less what? Well, if your problem is insulin resistance, which most people, as I said, 40 percent of even normal weight people have, eat less sugar. On the other hand, if your problem is insulin hypersecretion, which 20 percent of obese patients show, then it's going to be eat less refined carbohydrate.

LUSTIGSo sugar and refined carbohydrate drive insulin release and resistance. Those are the bad guys in the story. But you've heard that from many other people. That's not necessarily new. The fact that there are two insulin problems, not one, that might be new. In addition, exercise. Why? Because insulin sensitivity improves because you make mitochondria to burn energy rather than turning it into fat.

LUSTIGSo that helps insulin. And then lastly, there's medication. And ultimately, if you get further downstream, you might even need surgery. Now, I'm not for surgery, but, you know, you got to do what you got to do. And so we have sent kids to bariatric surgery when absolutely necessary.

REHMKids?

LUSTIGAbsolutely, we've done many.

REHMWow.

LUSTIGYeah.

REHMHere's an email from Kirsten in Brook Park, OH. Please ask about the role that the atypical anti-psychotic drugs that so many U.S. children are being given for behavior control. What role do they play in obesity, diabetes and metabolic syndrome?

LUSTIGVery good question. We have a lot of kids who are now on, quote, "mood stabilizers," unquote.

REHMLike Ritalin.

LUSTIGWell, Ritalin is not in a mood stabilizer, it's an ADD medication and doesn't cause obesity per se. The ones I'm talking about are, for instance, olanzapine or risperidone.

REHMI see, I see.

LUSTIGOr Geodon, aripiprazole, Abilify. There -- a whole host of these mood stabilizers to basically keep kids in their seats in school. The problem is they cause liver insulin resistance. And so, the pancreas has to make more insulin to make the liver do its job. That raises insulin levels all over the body and that drives weight gain. So we have a lot of kids on mood stabilizers who become massively obese and have metabolic syndrome. It's a disaster.

REHMAre parents told about that before they're given these drugs to give to their children?

LUSTIGSometimes. It depends on who the psychiatrist is, but often not.

REHMThat's pretty serious.

LUSTIGIt is very serious. And we are -- that's one of the reasons we have our clinic and one of the reasons why we are chockfull to the gills.

REHMAll right, now, tell me about the 16-ounce drinks that New York Mayor Bloomberg wants to ban in at least some places. What kind of role do either the sugar drinks or the diet drinks play in obesity?

LUSTIGWell, let's start out with the fact that we are currently consuming enormous amounts of sugar per day. The American Heart Association recommends that adult men consume up to nine teaspoons of added sugar per day and adult women up to six teaspoons of added sugar per day. Currently, the average American consumes 22 teaspoons of added sugar per day.

LUSTIGSo the American Heart Association recommends a reduction by two-thirds to three-quarters in order to get the toxic dose down into a manageable level, which would be very similar to, say, where we were at around World War II of last century. Right now, one-third of our sugar is consumed in soft drinks. One-sixth of our sugar is consumed in desserts, dairy products, ice cream, things like that.

LUSTIGBut one half of the sugar is in processed foods, hidden in various forms, whether it be the barbecue sauce, whether it be the salad dressing, whether it be the hamburger meat, all over, you know, the ketchup, et cetera. Bottom line, even if we got rid of soft drinks, even if we wipe them out tomorrow, we would still be above the toxic threshold for sugar consumption in America because of what the food industry has put in.

LUSTIGSo what Mayor Bloomberg has basically said is, look, we can't have people basically double dipping. That is, you know, eating what they want and then showing up in our emergency rooms and using up health care resources. We have to institute some sort of societal intervention that is going to at least try to put an end to some of this. Now, do I think that 16-ounce soda bans is going to solve obesity?

LUSTIGFirst of all, I didn't say sugar caused obesity. Remember, I said sugar metabolic syndrome. Big difference. So this will not solve the obesity epidemic. On the other hand, it's a baby step in the right direction. No one needs more than a 16-ounce drink. And to be honest with you, no one needs the soft drink in the first place.

REHMNobody needs the soft drink in the first place, but somehow we here in America have become more or less addicted to these products.

LUSTIGWell, and there's a reason for that. The fact is that Darwinian, you know, analysis shows that there are no food stuffs on the planet that are both sweet and acutely poisonous. So this is actually written into our DNA. We know that when we taste something sweet, we knew even, you know, our ancestors knew that this was safe. Think about this, got children? You have children?

REHMOf course.

LUSTIGOkay. Did you have trouble getting them to try new foods when they were babies?

REHMSure.

LUSTIGAbsolutely. How many times do you have to introduce a savory food to an infant before they'll accept it? On average, 13 times.

REHMThirteen?

LUSTIGThirteen.

REHMWoo.

LUSTIGIf that food is sweet, how many times do you have to introduce it?

REHMProbably a couple.

LUSTIGOnce.

REHMYeah.

LUSTIGJust once. And that's on purpose, because we are programmed to like sweet. Well, guess what, the food industry knows it. And so they have been applying extra sugar in all of our food. And that's why we are now up to 22 teaspoons per day because it works for them because they know when they add it, we buy more.

REHMAll right. And joining us now with a slightly different perspective is Dr. John Sievenpiper of St. Michael's Hospital in Toronto and McMaster University in Hamilton, Canada. Good morning to you, sir.

MR. JOHN SIEVENPIPERGood morning. Thank you for having me on the show.

REHMI gather you take some issue with Dr. Robert Lustig.

SIEVENPIPERWhat I want to say first is I know Professor Lustig. I think I commend him for his work. I think he spend a lot of attention in this issue. And I think what he's done really is underline the biological plausibility of a lot of these arguments. Where I differ I guess is whether this is actually really happening at population levels of intake in humans.

SIEVENPIPERWe've looked at the data carefully, looking at the (word?) of evidence that's used to inform public policy and clinical practice guidelines, which are controlled trials, which protect against bias the most. We don't see that fructose, for example, the main culprit in the story really behaved any differently than any other form of carbohydrate in terms of its effects on the features of the metabolic syndrome, which Professor Lustig was discussing, as well as overweight and obesity.

SIEVENPIPERIt's only when it's consumed in excess. So I think that we would agree on that that on excess that there's effect. Professor Lustig, I know in our discussions, have said that he thinks that we're all consuming excess. I think that's true for certainly parts of the population. But on the population level of intake, when you look at the same levels of intake in these studies, we don't see these effects.

LUSTIGSo, first of all, John, nice to talk with you again.

SIEVENPIPERNice to talk to you.

LUSTIGWe have kept this at an academic and scientific level and I continue to want to do so, and no problem there. So let's discuss the science of it. John, you're absolutely that in doses that make sense, that fructose does not do these issues. The problem is, in the hypercaloric state, as your data also shows...

SIEVENPIPERYes.

LUSTIG...it clearly does do this. The problem is, we're all hypercaloric. So that's, you know, the first issue. The second issue is fructose for glucose exchange studies, what you mentioned have inherent problems as well for the reasons we have discussed, that is that there is no fructose for glucose in nature, there's only fructose and glucose. And we know from the work of Marc Hellerstein and Lisa Hudgins that when you put fructose and glucose together, you get more liver fat than when you do fructose instead of glucose because the glucose takes up the glycolytic pathway, the fructose goes to the lipogenic pathway.

LUSTIGLastly, when you mentioned the question about population studies, we have now just finished a study and you've seen the data, which shows that sugar in a global sense, we're talking about across countries over the last decade, with all the appropriate confounders controlled for, including BMI, including obesity, aging, urbanization, physical inactivity and economics, sugar is 11 times more potent than total calories in explaining diabetes rate around the world.

REHMInteresting. Dr. Sievenpiper?

SIEVENPIPERYes. No, I mean, to his point, he's quite right in terms the limitations of the designs. But in those studies, it is -- those are consumed in a background of high carbohydrate foods, so it is present with glucose. What I would say, though, is what's interesting about this is if you look at this -- you look at the intakes of sugar, it's going up. Professor Lustig did discuss this and how that relates to diabetes and overweight and obesity and metabolic syndrome.

SIEVENPIPERAnd he's indicating what he's found with his new data is that we actually have a bit of a paradox, though, where in the last 10 years in the United States, for example, sugars have decreased to which the majority of the decrease coming from reduction in sugar-sweetened beverages. About 60 percent of that decrease.

LUSTIGMm-hmm. That's true.

SIEVENPIPERWell, people continue to consume a high level of energy and continue to become overweight and obese and we continue to have an issue of overweight and obesity increasing, diabetes increasing, metabolic syndrome increasing. We have seen some small decreases in overweight and obese particularly in adolescents. But in general, those numbers are still going up, despite sugars coming down.

SIEVENPIPERAnd we have the same paradox in Canada. We have the same paradox in the United Kingdom and Australia.

REHMThat's interesting.

SIEVENPIPERSo, on a population level, I think, you know, Professor Lustig said this and I don't want to -- I don't think that Professor Lustig thinks of this as the sole cause. I know he said it's not. And I think that's what I want to underline is that there are many pathways to overweight and obesity and metabolic syndrome and all the cardio-metabolic problems that come with this, including dietary patterns where you consume too much energy, you consume too much processed meat, too much refined carbohydrate.

SIEVENPIPERAnd sugary beverages and sugars are just one aspect of that. So they're culpable as culpable as any other form of excess energy. And I think the issue needs to be about excess energy or excess calories, if you like, in general. It's about overconsumption in this sort of culture we have of overconsumption, which I think is the issue and lack of exercise.

REHMDr. John Sievenpiper of St. Michael's Hospital in Toronto and McMaster University in Hamilton, Canada, thanks for joining us, sir.

SIEVENPIPERThank you.

REHMAnd now, there are great many people who want to know about artificial sugars.

LUSTIGRight.

REHMAnd whether it does increase weight. For example, says Anne in Gaithersburg, MD, who drinks like diet iced tea trick the body into gaining weight?

LUSTIGI wish I could answer the question. Unfortunately, we don't have the data. Now you'd say to me, but we've had these artificial sweeteners around for decades. How come we don't have the data? Well there's a reason we don't have the data and unfortunately it's not good. Let me explain very simply, there's something called pharmacokinetics and there's something pharmacodynamics.

LUSTIGPharmacokinetics is what your body does to a drug. Pharmacodynamics is what a drug does to your body. They are not the same. We have all the pharmacokinetics for all the diet sweeteners, for acesulfame K, for Stevia, for aspartame, for sucralose, et cetera. We have all of those because the FDA demands it before they'll put it on the market.

REHMIn other words, what it does to your body.

LUSTIGNo, the other way around.

REHMThe other way around?

LUSTIGWhat you do to it. We have all of those, because we do -- obviously the FDA is charged with preventing anything that could an acute poison from entering the marketplace.

REHMBut it seems to me it ought to be the other way around.

LUSTIGWell, me too, I think so as well. The point is pharmacodynamics is, for instance, what these drugs, these compounds do to your biochemistry, what they do to your leptin, what they do to your ghrelin, what they do to your insulin, what they do to your long-term intake.

REHMAnd you're telling me we don't know that.

LUSTIGWe don't know that and the reason is because the FDA doesn't demand it. The food industry can't make any money off that. It can only hurt their sales, not help them, so they don't do it. And then the NIH says, well that's the food industry's job, we're not going to pay for those studies. So they don't pay for them. So we have a dearth of information on what diet sweeteners actually do. In addition, here's another one for you, you put something sweet on the top. What happens?

LUSTIGInformation travels via a nerve from the tongue to the hypothalamus, the area of the brain that controls energy balance, says sugar bolus is coming, get ready to metabolize it. Brain then sends a message via a nerve called the Vegas nerve, which innervates your entire abdomen and goes to your pancreas and says, get ready to release the insulin. But then turned out it was a diet sweetener and the sugar bolus never comes.

LUSTIGWhat would the pancreas do? It's got all these insulin vesicles stored up, ready to go and nothing happens. So what does the pancreas do? Does it say, oh, gee, I thought the sugar was coming. I guess not, I'll wait until tomorrow. Or does it say, you know, I got all this insulin vesicles here, I'm going to go work on something and you end up overeating. We don't even know that.

REHMDr. Robert Lustig, he's new book is titled, "Fat Chance: Beating the Odds Against Sugar, Processed Food, Obesity and Disease."

REHMAnd welcome back. It's time to go to the phones, 800-433-8850. First to Pinehurst, N.C. Good morning, Susan. Thanks for joining us.

SUSANThank you, Diane. It's good to be on your program again. I'm a frequent listener and really enjoy your programs on health.

REHMThank you.

SUSANThis one is particularly interesting. I heard about this study about being fat is not so bad. And it was a very dangerous thing for me to hear because I know that people hear that because they want to hear that and they think oh, I'm okay. At 65 I decided I was going to probably die fairly soon. I've been morbidly obese the majority of my life fluctuating in huge weight amount gains and losses.

SUSANAnd I said, nope I've got to change. I have eliminated sugar from my diet, processed foods, I rarely eat meat. Didn't much before so it's not a huge loss for me. I don't eat dairy, so you could call me a vegan. I consider myself a follower of Dr. Joel Fuhrman and his diet program is nutritarian for those who don't know his work.

REHMTell me your question.

SUSANOkay. My question is more of a comment. I think it's -- the scientific information is very important. I follow it. It's interesting. It helps me to keep on track. However, I think the most important thing is that we as Americans and Western world have to radically change the way we eat. It cannot be just taking out a little sugar. It cannot be just taking out a little of this. If you are a food addict you can't have a little of it. And most people can't get by on just a little. So I don't know what the solution is but the scientific information is great. But what can we do as a nation to change drastically the way we eat?

LUSTIGWell, I'm going to try to answer that for you very simply. What my book does is it tries to look at all of these various diets that are out there today, the Atkins Diet, The ornish Diet, the paleo diet, the south beach diet, the glycemic index diet. You know what? They all work except they don't. Why don't they work? Because every diet regresses to the mean after two months. That's what Christopher Gardener showed in his Stanford A to Z study.

LUSTIGBottom line is we can't stay on a diet. What I'm saying is that the single two things that every diet that works share in common are low sugar, high fiber. And you know what a low-sugar, high-fiber diet is called? It's called real food. That's what real food is. This is about processed food in America and the fact that processed food has basically taken over real food. And in the -- and there are reasons why having to do with cost, expense, depreciation, etcetera. But the bottom line is that processed food works for the food industry. It does not work for our biochemistry.

REHMWhat about the new rage over Greek yogurt?

LUSTIGSo Greek yogurt made in Greece is just great. Greek yogurt made in America is just terrible. And there's a very simple reason. What is yogurt? It is sour milk, okay? It is soured by specific bacterial that you choose to sour it. And the reason you do that is because number one, it has mild probiotic effects which are good for the intestine. And because that way you get to choose what it tastes like because you've chosen the culture.

LUSTIGThe point is that yogurt is sour milk except in America where yogurt is sweet. I just saw the movie "Parental Guidance" over the weekend with my kids. And there's a scene in it where the kids actually taste ice cream for the first time and they actually hit their mother and say, you told us that yogurt tasted just like ice cream. Indeed it does because the fact is in America Yogurt is sweet. The reason? They took the fat out. You know, low fat food tastes like cardboard. Skim milk tastes horrible. You can't get a kid to drink it in school. So what do they do? They add the sugar. It's called chocolate milk, it's called strawberry milk.

LUSTIGAnd then the school system says, well we got to get our kids to drink milk somehow. How about bringing back whole milk? Because the saturated fat in whole milk was a hell of a lot less dangerous than all the sugar that they put in.

REHMInteresting. Interesting. You said that there was an op-ed piece recently about yogurt.

LUSTIGRight. Yesterday I wrote an op-ed in the San Francisco Chronicle. You can get it online. It's called Defusing the Health Care Time bomb" and the subheading was "Yogurt's a Health Food?" And it's very specifically designed to make people wake up and realize what it is that's happened to our processed food supply and how it doesn't work for you.

REHMYou know, I used to make yogurt at home. And the way you do that is to start with a tablespoon of yogurt. Usually that was passed from family to family. More recently it has to be started with a processed yogurt.

LUSTIGWell, in fact, what they do is they add the sugar very specifically to try to mitigate the sourness of it. Let me give you an example for pomegranate yogurt. Pomegranate yogurt has 19 grams of sugar while a standard plain yogurt has 7 grams of sugar. That means there are 12 grams of added sugar in a pomegranate yogurt. That's the same as a bowl of Captain Crunch.

REHMBut if I'm eating plain yogurt I'm sure getting a lot less sugar.

LUSTIGYou're getting 7 grams of quote "sugar." That is lactose. That's milk sugar. And the galactose gets converted to glucose. And remember glucose is not the big problem. It's the fructose that's the problem. It's the sweet stuff that's the problem. So if you want to make -- you know, to either purchase or to make your own yogurt and it's plain and you add whole fruit to it to try to mitigate some of the sourness, terrific, fantastic. I'm all for it. But to buy processed yogurt in the store today, that's the problem.

REHMAll right. To Bert, Va. Good morning, Maria.

MARIAMy question to the doctor is, lately I've been trying to change and -- to raw sugar. I know it's still pretty bad but I did always be using Stevia. And I want to know what do you -- his opinion on that.

LUSTIGWell, going back to the Stevia question is the same issue that I said with all the other diet sweeteners. We don't have the information yet. And unfortunately we're not going to be getting the information any time soon. So I have to remain agnostic on that point because the science, the data just isn't there. Now as to the question of raw sugar, it doesn't matter. There are 56 names for sugar and they're actually in the book listed. And that's very much on purpose.

LUSTIGThe food industry does that very specifically because the nutrition labeling and education act of 1990, which gave us nutrition facts, the little box on the side of each package, they have to list each item in the food based on mass. So they can make different forms of sugar numbers five, six, seven, eight, nine and ten. When you add it up it's number one. The problem is they can hide it in many, many different ways. And that's basically a perpetration of a fraud on the public...

REHMHere is...

LUSTIG...and we're trying to fix that.

REHM...here is an email from Andrew in Washington who says, "If the amount of visceral fat is linked to health, it would seem to follow that liposuction to remove stomach fat would improve health. Is there any research on this?"

LUSTIGThere is no way to remove visceral fat. Liposuction is for subcutaneous fat. And actually Sam Klein at Washington University, St. Louis did this study in 2003 in the New England Journal of Medicine where he looked at the metabolic status of people who had undergone liposuction. And showed that there was absolutely no change in their metabolic dysfunction.

REHMInteresting.

LUSTIGIf we could get rid of visceral fat that would be great. People are looking into ways to hopefully do that but none of them are ready for prime time.

REHMAll right. To Syracuse, N.Y. and to Greg. Good morning.

GREGGood morning. Thanks for taking my call.

REHMSure.

GREGFascinating subject and I will get right out and buy that book.

LUSTIGThank you.

GREGI have two households. My ex-wife and I have a son that is seven, diagnosed with a brain tumor that's disseminated multifocal through his brain and spine.

REHMOh, I'm so sorry.

LUSTIGSo sorry. I take care of these patients for a living. I'm a neuroendocrinologist and my bread and butter is kids with brain tumors. So I totally understand and I'm deeply sympathetic.

GREGWell, thank you. It's a low grade glioma and he's being treated in Boston at Children's Hospital Boston with a great team out there. And my question is, my wife is -- ex-wife is a nurse and we have a huge disagreement in terms of the role of sugar. I am adamantly opposed to sugar. I don't want it, you know, in my house. And I guess, you know, we need somebody to kind of break the tie. And being a nurse it's hard to convince her that, you know, sugar is dangerous or, you know, not healthy for him.

GREGBut the thought came to me when we were doing a pet scan with him and how he couldn't have sugar for, you know, a certain amount of time prior to the pet. And I thought, hum, cancer rapidly dividing cells, sugar, same type of thing. And so I just thought maybe you could weigh in on that. And the side question I had was, I have a slightly fatty liver. And I wanted to know if that is a precursor to having the fat on the inside that you talked about. And thank you.

LUSTIGAbsolutely. So the answer to the second question first, yes, the fatty liver is the thing that drives all of that -- those other problems. Because when you have fatty liver then your liver doesn't work right. That raises insulin levels and that -- all over the body and that's going to drive excess energy to wherever it can, including other visceral stores and also into subcutaneous stores. So fatty liver is a precursor to virtually every one of those metabolic dysfunctions that we talked about.

REHMSo what about sugar and the brain tumor?

LUSTIGRight. So that's a big question and it's very complicated. In ten words or less you said, sir, that, you know, you don't know if sugar's necessary. The fact is that fructose, the sweet part of sugar is not necessary for any biochemical reaction in any human. There is not one biochemical reaction that requires dietary fructose.

LUSTIGNow, we know that tumors grow in response to insulin. Insulin is a growth factor for tumors. And I don't know if you saw the 60-Minutes episode on sugar back in April but Lewis Cantley who is at Beth Israel Hospital, now at Mount Sinai, basically said that the insulin resistance that's driven by sugar is one of the major promoters of tumor formation. Now brain tumors are slightly different and probably are behind the blood brain barriers. It's probably not as big a deal in terms of tumor growth for a brain tumor as it would be say for a solid tumor somewhere else in the body.

LUSTIGBut we also now know from work from UCLA from Ahini (sp?) that many tumors have an enzyme that will break down sugar to use specifically for its own purposes, especially pancreatic tumors. And whether or not that is something that goes across other types of tumors or not is still something that's open to investigation. Bottom line no one needs the stuff.

REHMSo you are most definitely saying to Greg as far as fatty liver is concerned that sugar should be out of the question for him.

LUSTIGBottom line, sugar was meant to be a treat, not a diet staple. If we are consuming 22 teaspoons of added sugar per day it's a diet staple. We're supposed to have sugar once a week, not once a meal.

REHMAnd you're listening to "The Diane Rehm Show." Now to Dallas, Texas. Good morning, Niva.

NIVAGood morning.

REHMGo right ahead, please.

NIVAI'm a registered dietician in Dallas, Texas and I have been for over 30 years. And during this time, I've seen a lot of different books come out about losing weight. You know, Dr. Atkins' first book was out when I was early in my career. My concern as a dietician is that there are so many magic bullets that these books put out that purport that one ingredient or one food is the culprit. What is frustrating is that then people buy into this and then they fail and then they go on to the next one.

NIVAI wish that we could somehow get the point across that it's the total diet. It's the total calories and that if you're going to maintain that weigh loss over the long term, that you need to reduce your calories and you need to exercise more. Watch your portions, all the things that people think are boring. They want some quick easy fix. So I guess my question is -- and I think that Dr. Lustig did address this a little bit -- is like how do we get this point across to people that there's no magic bullets when it comes to weight. It's a matter of energy in and energy out.

NIVAAnd, you know, we know from the national weight control registry that there are certain -- that people can lose weight on everything from Atkins to Zoe but the people that keep it off are doing very sensible things like always eating breakfast. They are exercising. They're self monitoring and they're following, like you said, a high-carb, low-fat diet.

LUSTIGMa'am, I couldn't disagree with you more. And in fact what you espouse is what virtually every dietician basically says. And I -- as far as I'm concerned it's this kind of thinking that is part of the problem, not part of the solution. And let me explain why. You said it's about the total number of calories. What you're saying basically is a calorie is a calorie. And what the book goes into in very, very distinct detail is that a calorie is not a calorie. A calorie burned is a calorie burned. So for instance, if you are on the couch and you burn a certain number of calories that's equivalent to say, you know, one minute of jogging, so a calorie burned is a calorie burned. But a calorie eaten is not a calorie eaten.

LUSTIGLet me give you four different ways that a calorie eaten is not a calorie eaten. Almonds. You consume 160 calories in almonds. How many of those calories do you absorb? It turns out 130. What happened to the other 30? Because of the fiber in the almonds they get delivered further down the intestine. And so the bacteria in the intestine consume those. So you ate them, but you didn't absorb them. So a calorie is not a calorie.

LUSTIGNumber two, fats. We have omega 3s which are heart healthy and actually good for you. We also have trans fats that are the devil incarnate and will kill you. Both 9 calories per gram. If a calorie were a calorie it wouldn't matter, but it matters a lot and you know it. Number three, protein. It turns out you have to put double the amount of energy in to protein to digest it for energy as you do for carbohydrate. So you actually expend more energy digesting protein than you do carbohydrate, because a calorie is not a calorie.

LUSTIGAnd then finally fructose and glucose. Please don't tell me that you think that fructose and glucose are equivalent. Because if you do that you are part of the problem, ma'am.

REHMDo you eat meat?

LUSTIGOh, you bet I do. I love a good steak. Now, what about meat? Well, it turns out there are two kinds of meat. There's the kind in Buenos Aires which is grass fed and very lean and delicious but very red. It looks like muscle. And then we have what we have here in America which is all this marbled stuff. Well, guess what? That marbling is muscle insulin resistance. Those animals have the same metabolic dysfunction we do. We just kill them before they get sick.

REHMAnd that's got to be the last work, Dr. Robert Lustig. His new book is titled "Fat Chance: Beating the Odds Against Sugar, Processed Foods, Obesity and Disease." Read it and think about your own approach to food. Thank you.

LUSTIGThank you.

REHMAnd thank for listening all. I'm Diane Rehm.