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interview: arthur agatston, m.d.

I'm going to be the self-obsessed reporter here for just a minute, and ask you about my own medical condition. I'm soon to be 55, 5'11," and last time I got on a scale in my doctor's office last week, I was 210 lbs. I have gone up. In my college athlete days, I was about 165-180 a lot of my life. Last 10 years, I think I went from 190 to 210. My blood pressure is not high, but it's up there. I've been thinking about diets. So obviously you haven't given me a physical, haven't weighed me in, but what would you say to someone like me?

Well, your story is really quite typical of American baby boomers, who were very similar weights in college, in the 140s, 50s, 60s, 70s, and have gained 20, 30, 40 pounds as adults. And that's really part of our national epidemic of obesity, which has also led to diabetes and other chronic problems. The question is why.

I actually give Dr. Atkins credit for teaching us that fat doesn't necessarily make us fat.  And he was absolutely right.

We exercise less. There's the oversized portions. But really what happened at the time this epidemic started were the national recommendations on low-fat, [high]-carb diets, and the response of the food industry, with all the great low-fat, high-carb, processed carbohydrate foods. Basically the idea was that the low-fat, high-carb diet was to mimic underdeveloped countries, which are low fat, high carb, no heart attacks, no strokes, no obesity. What the American food industry produced, though, was carbohydrates where the fiber as well as the nutrients were taken out. …

And in fact, what ended up was an unintended experiment in this country. There've been countries, societies that have been high-fat, who have done well. Some Mediterranean countries, the island of Crete was studied very, very carefully; the Greenland Eskimos have been studied. Those are high-fat societies that do fine as far as cardiovascular disease and obesity. And we mentioned the underdeveloped world, [which] tends to be low-fat, high-carbohydrate, also do[es] well.

Dr. Arthur Agatston is a cardiologist and author of The South Beach Diet. He says that the fallout from the low-fat diets of the past few decades was an "unintended experiment," in which Americans substituted highly processed carbohydrates for fat, which resulted in the current obesity epidemic. In this interview, he discusses how he developed the South Beach Diet, and why he considers it the successor to Atkins and other low-carb diets. Agatston also explains the concept of the glycemic index, which measures how foods affect blood sugar, and its importance in cardiac health. This interview was conducted Jan. 7, 2004.

No society was ever low-fat, high-processed carbohydrate. That was a new experiment, as well as throwing in trans fats, those of the hydrogenated oils found in commercial baked goods and cookies that are over-the-counter. Those turn out to be the worst fats, and the worst for both our blood vessels and long-term weight loss.

What the processed carbohydrates do is, they are rapidly digested. That causes swings in our blood sugar where we're hungry soon after we finish a meal, and we're ready to eat some more. Basically Americans are walking around hungry all the time, and [I believe strongly that's the primary cause] of the epidemic of obesity.

So I walk into your office here in Miami. I'm 55, 5'11", 210 pounds, blood pressure sort of 128/90, say. And what do you advise me? What should I do?

Well, first we certainly get a family history. Is there heart disease in the family? Is there any diabetes in the family? And we look -- are you still exercising, which is important, and when the weight gain occurred.

Adult weight gain and degree of weight gain is an independent risk factor for future heart attack and stroke, and particularly if the weight gain tends to be central.

Right. Where it is.

Yeah, where the arms and legs are relatively thin and muscular, and most of the weight is there [at the center]. That's very much a sign of some degree of what we call insulin resistance or pre-diabetes, the metabolic syndrome. There are many names for it. But basically, it indicates that our body is not handling sugars and fats optimally after we eat and is creating high insulin levels that deposits fat in our bellies. For early man, when you would go through times of feast and famine, if you were able during feast to store some fat in your belly, and then the famine came, you could live off that fat during the famine. But today, when there's no famine, there's only feast, the belly gets bigger and bigger, and what was a survival advantage for early man becomes a problem.

Doesn't work so well now.


No. As you say, no famine, thank God, in this country.

One thing that we're finding around the world, we are exporting this epidemic of obesity and diabetes. Societies that had famine in recent centuries -- the Indians of Asia, the Chinese -- when they move and adopt a Western diet, they have really epidemic diabetes and obesity, out of proportion to Westerners. And in China today, diabetes is a new problem because of new over-nutrition, and they really had adjusted to a more subsistence diet. So what helped them survive a century or two centuries ago is hurting them today.

More and more I hear about and have seen young people getting diabetes. I mean, you always had the code word "adult onset" for type 2 diabetes but now you're seeing it in young people, which is really depressing, scary.

Exactly. We're seeing what we called "adult-onset diabetes" -- now we call it "type 2," but it is traditionally the adult onset -- in teenagers and even in preteens, and a horrible epidemic of obesity in our schools. We actually are planning some studies and interventions; we think going after the young people with both education and strategies to improve their diet is particularly important in this country.

I mean, the temptations in America today, starting in high schools, where you get Pizza Hut deliveries and super-sized Cokes, to movie theaters, [where] you could drown in the bucket of Coke you get, to just walking through a mall in America today, it's hard to avoid fast food.

And one thing that's been a particular problem is, with economic difficulties, schools have been able to make deals with soda companies and other companies to bring in vending machines. …

It's like a deal with the devil. You know, you get the band uniforms but you get the incredible high fructose corn syrup.

Exactly, exactly. One of the good things is, the way the food industry responded with all these great tasting, low-fat, low-cholesterol [products], which they did sincerely. At the time that those low-fat, high-carb recommendations were promulgated, we didn't have the concept of fiber and what we call glycemic index today.

The glycemic index basically teaches us that a white potato increases our blood sugar faster than table sugar does, and basically, the higher the glycemic index of a food, the faster you get swings in blood sugar, and the more hungry you are soon after you finish a meal. And now that demands are switching to both low carb and less-processed carb, the food industries are responding, and there are new technologies out there that will help us to some degree have our cake and eat it too, have foods that taste good but that are more slowly digested and don't cause the hunger soon after we eat.

Because you put [in] more fiber, roughage or whatever?

Yeah. There's actually new technologies with starches that, once they hit the stomach and hit the acid, become more gelatinous and more, in a sense, fibrous. And they are emptied more slowly from the stomach and are digested more slowly, so you don't get those swings in blood sugar that you get with, say, white bread.

Let me ask you about your book, because The South Beach Diet is everywhere. I mean, I'll level with you. I never thought about a diet in my life until recently. But you walk into an airport bookstore, and The South Beach Diet is at the top of a very large stack of books about dieting. And the first thing that caught my eye here was "Lose belly fat first." Now, as a mid-50s male, I'm looking at my belly thinking, "That's where it is." You know. Is this really going to work?

Well, belly fat is actually metabolically different than subcutaneous fat -- fat under our skin in other parts of the body. And it is deposited because of elevated levels of insulin, [as] part of that survival mechanism. It's metabolically active. It produces some inflammatory factors. C-reactive protein has been in the news as a risk factor for heart disease. And it is metabolically different than other fat.

When you have more slowly digested food, the good carbs and the good fats, you lower your insulin levels and the belly simply melts away. It's very predictable. And the more that you've had adult weight gain, and the more it's been central weight gain, the more predictable it is that the South Beach Diet will work for you.

… We were at the Pritikin Institute yesterday, and they say there's absolutely no scientific basis that you would lose your belly fat first.

Well, in the clinical trial that we performed, it was a small trial but it was our diet versus a very low-fat, high-carb diet, the Step 2 Heart Association diet of the mid-'90s. The Heart Association has changed their diet recommendations. But in this, we measured hip-to-waist ratio, and there was a significant decrease in waist-versus-hip size in our diet, but not the low-fat diet.

And that's the pear shape versus apple shape idea?


Tell me about that a little bit.

Yeah. There were the first studies really in the 1980s, that people who were apple shaped, with larger bellies and thinner legs, as opposed to the pear, with bigger buttocks and thighs, that they were at a higher risk for heart disease. And now we understand why. It's because they tend to have the high insulin levels, which is a risk factor in itself. High insulin levels are an independent risk factor for heart attack and stroke. And the predominant belly apple shape is an indication of this abnormal pre-diabetes physiology.

So I have kind of big thighs. Always have had them. My football coaches liked those. But that's not necessarily bad if my overall weight's okay?

Right, exactly. That in itself is not a risk factor for coronary artery disease.

But it is the belly?

The belly fat is, and often there's a correlation. But there's some people where there are other genetic and metabolic causes of obesity which we don't understand very well. And it tends to be from childhood and runs in families. They often have very good triglyceride and good cholesterol levels. You can tell then metabolically as well as visually. It's a more difficult nut to crack. It's harder for them to lose weight.

What's the summary of the South Beach Diet and the premise that it's based upon?

It's based on several principles: Good fats -- we have healthy fats. It's not necessarily low or high fat. The good carbohydrates -- it can be low or high carbohydrate. At the beginning, strategic snacking. And those principles really can carry through for years and years.

Fat has been demonized by all the low-fat diets. But you're saying you need some fat?

Absolutely. And many fats are very good for us. The predominant fat in this country for many years was saturated fat, and that is not wonderful for our vessels. It does increase the risk for heart disease, although probably not as much as we originally thought. The new fat we have are the trans fats, the hydrogenated oils found in the commercial baked goods, and those are the worst fats. They increase our bad cholesterol; they decrease our good cholesterol; they're probably associated with increased death rates; they're absolutely horrible. The good fats are the Mediterranean oils: olive oil, canola oil, the omega-3 fish oils. Most of the oils found in nuts are actually good fats, and they're not neutral. They actually help keep our vessels healthy and they help long-term weight loss.

Yesterday, we're at the Pritikin Spa, and they're giving us a lecture and olive oil's the enemy. They say, "Whatever you do, don't put this on your pasta and vegetables. You're raising the caloric intake tremendously. Do not eat olive oil."

Well, as far as vessels, the largest positive diet study that's ever been done was the Lyon Heart Study in France, where they took people who had already had heart attacks, gave them a Mediterranean diet, which the main addition was basically olive oil and canola oil, which has the omega-3 fish oil in it. And there was a decrease in heart attack rate by 70 percent.

There is calories in oils, and it's a higher density in fats or oil than it is in carbohydrates. That threw us off for years. I actually give Dr. Atkins credit for teaching us that fat doesn't necessarily make us fat, and he was absolutely right. But the thing is, you cannot sit around watching a football game and just inhaling olive oil and, for instance, steak, like you can pretzels or potato chips, carbohydrates, because you become satiated. Whereas with processed carbohydrates, you can basically eat them all day, and rather than being satiated, you actually get more hungry as you eat them. This wasn't understood years ago.

But the idea that you can just count calories -- calories are the bottom line in the end, but the reason why we're consuming more calories is not the size of our portions. It's because of the type of calories we're consuming, particularly the type of carbohydrates we're consuming, that makes us hungry all the time.

So when I make it to -- assuming I do -- phase two of the South Beach Diet, your diet, a lean steak and even a glass of red wine, okay. But pretzels, beer, potato chips, no way.

Yes. Absolutely. And it's interesting. The wine, alcohol is counter-intuitive, but so many studies have shown that alcohol actually in moderation can prevent not only heart disease but diabetes. It turns out that with a meal, that glass of red wine helps delay stomach emptying. So again, it delays digestion so it decreases the swing in blood sugar that you get after you eat, say, with pretzels.

There is, and has been in this country for a long time, a sort of low-fat orthodoxy. You go into a supermarket and you see everything low fat. And that's the good, smart choice is to pick the low-fat diet. What's wrong with that?

Well, to be low fat, what is substituted is often processed carbohydrate. And, you know, in the '80s, early '90s, I thought I could have anything that was low fat, low cholesterol, in bulk form. I would have the processed cookies, and I would finish a box at a time. I said, "Boy, they're low fat. I'm fine." I was watching my patients getting fatter, the country getting fatter, and frankly I was watching myself getting fatter on all this low-fat labeled food, and it was correctly labeled low fat. It's just the processed carbohydrates that actually make us fat, not fat.

So the low fat didn't mean you wouldn't get fat if you kept eating these, it meant literally the fat content?

One of our rules is: "Low fat" means it's going to be fattening. One of the other rules is "fortified" means it's devoid of vitamins and nutrients, because the reason they're saying "fortified," it's been processed, and all the natural vitamins and nutrients have been removed, and they've thrown some vitamins in.

What we know now is, we don't know how to throw vitamins back in. In fact, supplements which we thought would be good -- vitamin E, vitamin C -- we know in several major studies now, the good news is they don't appear to hurt us; the bad news is, they're not helping. They make expensive urine, basically.

Tell me a little bit about how you came to this. You're a cardiologist. Now suddenly you're doing diet nutrition. What happened?

… I was watching my patients and the country getting fatter, as well as myself. And around this time, in the early '90s, there was the first reports of this pre-diabetes insulin resistance syndrome, this central obesity, abnormal insulin and sugar metabolism, leading to obesity. I observed patients on Atkins, on the Zone diets, who in fact did well. And I read the books, and a lot of what they said made sense, but I did not want to give saturated fat to heart patients. Around this time [there] was also literature, studies like the Lyon Heart Study, about the good fats -- that not all fats were bad; some fats were good for us -- and also that not all carbohydrates were the same. We didn't have to eliminate all carbohydrates to get thin. That the vegetables and the whole grains are really good carbs that are good for us.

So we decided to try a diet basically of the good fats and the good carbs, in myself and in my patients first. I was amazed by the results, after really giving up on doing diet counseling, on having all these patients come back thinner and feeling better. We were giving out just little xerox sheets of the diet, and people were sending it all over the country. And we began to report our experience, first with consecutive case reports and then with a small clinical trial. When we reported in national meetings, the local media picked it up and they asked us to put South Florida on the diet. Just over TV and in partnership with local supermarkets, South Florida did extremely well. It was in the month of May for three years, three years running. And that sort of took us from an academic project into the public eye, and led to the book with the glitzy name, but we happen to be here in South Beach. …

In your mind, what's really wrong with the Pritikin approach?

Well, for one thing, people just don't stay on it, frankly, Pritikin and Dr. Ornish, [whose diet] is also very low-fat approach. And he admits that his diet is not for most people, that most people will not stay on it, because it's just not palatable when you're eliminating all the fat. But the good news is the fat that we add is not just to make the diet palatable. It is good for us. The literature on nuts and omega-3 fish oils being good for our vessels and good for us is really overwhelming and there's new literature coming out all the time. …

Let me ask you about the baked potato. … You're not so crazy about baked potatoes. Why not?

Right. Because of the glycemic index, that if you have a scoop of baked white potato -- a sweet potato is not so bad -- you increase your blood sugar just as fast as if you consume table sugar.

Really? A baked potato, table sugar.

Yeah. And, you know, in Ireland, where potatoes were a staple, as well as beer, [there's] just a huge rate of coronary disease. The beer is interesting because beer contains maltose, unlike wine and other alcoholic beverages. Maltose is two glucose molecules -- sugar molecules -- stuck together, and it raises your blood sugar faster than anything. That's why we think we get beer bellies and not wine bellies or vodka bellies.

Any modifications of your diet since publishing it?

Yes. We're very much a diet in evolution, and as new information comes, we have no problem about adding. As a matter of fact, there was a misunderstanding about carrots, which we thought in the original studies were high glycemic, raise your blood sugar quickly. And they don't. There're new studies, and so we're allowing carrots in earlier phases. And dairy products, believe it or not, are looking better and better. And dairy in moderation, yogurt, were allowed--

Non-fat? Non-fat dairy?

Yes. Well, low-fat. Not non-fat. But dairy, the sugar in dairy is digested slowly, and actually there are studies of dairy being associated with less weight gain and less diabetes.

So low-fat milk, low-fat yogurt?


Without a lot of sugar in it.

Without a lot of sugar, yes. What we do sometimes with a plain yogurt is add an artificial sweetener. It tastes good and it's good for you.

Fruit. I love fruit. I grew up in California, grew up drinking a lot of orange juice, both on my mother's orders, [and] because I liked the taste of it. Orange juice turns out to be not so terrific, right?

Well, concentrated orange juice, where you've taken out the pulp and again the nutrient, the fiber, and just concentrated a lot of juice, is drinking a lot of sugar. And I always recall the experience I had with a patient who came in with a very high blood sugar, new onset diabetes. Usually [we] would expect [the cause to be] an infection or recent surgery. What it was, was that they got a juice machine in the office, and he was drinking juice all day. And once he stopped, the diabetes resolved.

Basically, whole fruits are very good for you. They have fiber. They have wonderful natural vitamins and nutrients, but when you take a lot of whole fruits and concentrate the juice, that's a problem. It's a problem particularly with our babies and toddlers, where mothers -- and we did this with our children -- just giving them apple juice and apple juice concentrates. That's concentrated sugar. …

People have told me that bakeries are closing down because of the popularity of the South Beach Diet. They're going out of business.

Well, all they have to do is make whole grain, and they'll stay in business. But when you take the fiber out of the bread, again, you're taking the nutrients, the vitamins, and you're left with empty calories that cause large swings in blood sugar, and it's a disaster for the country. But if you make whole grain bread, which takes longer to chew and to eat and digest, that is fine. Pita bread, sourdough bread -- which is acidic and delays digestion -- there are certainly good breads.

Sourdough's okay, more or less.

Sourdough, yeah. Not in excess. But sourdough, which is acidic, helps slow stomach emptying, as does, for instance, the vinegar in a vinaigrette dressing. If you put lemon on your salad, on your fish during a meal, that also will delay stomach emptying and digestion.

Let me ask you about exercise. Americans like to think of themselves as fit and tough and football players, but honestly, kind of lazy a lot of the time. Is exercise important to your diet?

Yeah, exercise is absolutely crucial. And it's been a little bit misunderstood with our diet because when we did our clinical study, we asked patients not to change their exercise habits because we wanted to study the diet and not exercise. But I am a huge proponent of exercise, and the point we make in the book is, often less is more; that studies show that the first 20 to 30 minutes of just a brisk walk, 3 to 5 days a week, can decrease your risk of heart attack substantially and helps with obesity. Now, if you can do more and go to the gym and do stretching and weight-bearing exercise, that really gives you incremental value. But going from nothing to the first 20 to 30 minutes makes the biggest bang for the buck.

Like 30 minutes a day of walking, some kind of exercise.

Yes, and it can be at different times. It can be two 15-minute intervals. What happens as we age, in this country in particular, and we don't exercise, is we decrease our lean body mass. That's our muscle and bone mass, and that's responsible for our basal metabolic rate, basically how many calories we're burning when we're sleeping. By exercising regularly and doing some weight-bearing exercise, you maintain that lean body mass, the muscle and bone mass, and it's much easier to lose weight because you're literally burning more calories while you're sleeping than if you've lost that muscle and bone mass.

Now, in a job like mine, where I'm sitting around an editing room, say, all week, long hours, (A) you want to snack, and (B) you're sitting down. Then the weekend comes along and you go out and play touch football. Doesn't do it?

That can cause orthopedic problems. You know, even the classic gentleman up north who goes and shovels snow and has a heart attack -- it's not so much the snow shoveling. It's because they've been doing nothing, all of a sudden they're exercising vigorously, which causes a huge pulse of adrenaline that can set off a heart attack.

But when you exercise regularly, you actually decrease both your resting adrenaline levels and the response to exercise, and you're much safer from a heart attack or sudden death. But the message is, it has to be regular. You have to find a time during the week for at least that 20 to 30 minutes of a brisk walk, of -- breaking a sweat is a good threshold. If you break a sweat on a regular basis, that's a great start. …

From your point of view, what's wrong, if anything, with the Atkins diet?

Well, we do emphasize that our diet is a lifestyle, not a diet. The way we developed it for our heart patients, losing weight or normalizing your blood chemistry just for a few weeks or a few months does nothing to prevent a heart attack or stroke. It has to be over years.

The problem with the Atkins diet is, firstly he lumped all fats together, including saturated fats, at the beginning even trans fats, and said they're good.

They're all okay.

They're all okay.

And you're telling me trans fat's terrible.

Trans fat's terrible. Saturated fat's bad. Mediterranean oil's good. The other thing was basically lumping all carbohydrates together. And again I give Dr. Atkins credit. At that time, we didn't understand the importance of fiber or the concept of glycemic index. And he felt that you had to avoid basically all carbohydrates. You would deplete your sugar storage in your liver, and you would begin burning fat for energy. And that caused the creation of something called ketone bodies, ketosis, and he felt ketosis was the reason why we weren't hungry on the diet, and that's how we lost weight.

When you eliminate all those carbohydrates, including the vegetables with all the good nutrients, you're eliminating very important sources of vitamins and minerals, and we didn't want to do that. Also, when you go into ketosis, you lose a substantial amount of water, and particularly with older heart patients, we didn't want dehydration. So we gave our patients enough carbohydrates so that they didn't go into ketosis, and we measured that. We found still in the first two weeks, they lost their cravings for sugars and lost weight without difficulty. So you could have the healthy carbs and still lose cravings and lose weight.

The other thing about the bad fats is, as far as sugar and insulin metabolism, they are not good for it long term, whereas the good fats are, and that may be part of what makes people go off those diets and balloon up after a year. It's really important to have a transition into a lifestyle, a maintenance phase, and one that's simple, and we emphasize that very much.

Otherwise you get the classic yo-yo dieter, right?


They tell me that that's worse than just sort of staying the way you are.

It is. There's actually been a mixture of literature on this and it's gone both ways. And what I think is [for] those who have central obesity, it's easier for them to yo-yo diet. I think it's actually the selection of people who have the apple shape and have greater risk for heart disease in the first place. Those who were obese from childhood, where it's more difficult to lose any weight, are less likely to yo-yo in the first place, and they're actually at lower risk for heart disease in the first place. I think that's the reason why there's been a conflict in the literature on that.

Now, the low-fat people, when they look at your diet, they look at the Atkins diet, which I think they have even more trouble with, they say, "Look, this is just too good to be true. And, at its most dangerous, there's too much protein. You're eating too much steak. This could kill you."

Well, protein -- first of all, on our diet, it can be either high or low protein. We have people on it who have kidney insufficiency and are supposed to limit protein. It's still healthy for them to have whole grains, whole fruits, a lot of vegetables, and good oils. You just have to have more of the good carbohydrates and the good fats, and less protein. For young body builders and young people in general, high protein is absolutely fine.

Really, our diet is the way man was meant to eat, and did eat traditionally. People in the 1950s, before our epidemic of obesity and diabetes, were not walking around hungry all the time. And if you went to Disneyland in 1950s, it's not like Disneyland now. And the difference is the types of carbohydrates rather than just exercise or portion size. …

I've got to say, and it's too early to tell probably, but first three days, feeling not satisfied has not been the problem for me, trying [a low-carb] diet. I mean, you can fill yourself up. Not that I don't miss bread.

I don't think you will, though. People lose their craving and they don't walk around hungry, because you can exert great self-control for a short period of time and lose some weight, but there's no way that you're going to do that for weeks, months, or years. You have to have a diet that tastes good, that has variety, and that's satisfying. And that's what the South Beach Diet is.

The one problem we find long-term is those people who are interested in food and cook their own food and create great varieties, do the best. Those on the run, traveling, where you need more convenient food, that's where people run into trouble. That's where I've run into trouble. And that's where I think the restaurant and the food industry is responding and will respond, so it will be easier and easier to find good choices when you're on the run, when you're traveling. If we could all go back to the family dinners with whole foods of decades ago, that would be wonderful, but it doesn't look like that's going to happen.

Leave It to Beaver.

Right. Yes. They were not fat, and they were not running around hungry all the time.

Right. And in fact, you know, to jump ahead of the game, I was on that show. Jerry Mathers, who was the star, had a big problem with weight, and he now has type 2 diabetes.

Yeah. Diabetes has been a problem in the country from the 1950s. But it's increased five- to seven-fold since the 1980s, since we've really changed to the high carb. And certainly food was plentiful in the "Leave It to Beaver" era.


Food was available. And depending on your genetics, it's a certain amount of weight that you gain when you turn on this insulin resistance syndrome, which basically amplifies the swings in blood sugar where you're more hungry. So if he had a big dose of this genetic predisposition, a little weight would have begun to cause these big swings in blood sugar. For most of us, it takes more weight gain. But with the carbohydrates introduced in the '80s and '90s, more of us have hit that threshold where we have abnormal insulin action and where we're hungry all the time. …

[Some people] say the perfect thing to keep you from being hungry is a baked potato, and you're saying the opposite.

Well, one thing I might say -- and I think schools of nutrition should have looked at this -- is it's like people voting with their feet. They're voting with what types of diets they're going out and buying. Since Atkins, people are going for the carbohydrate-limited diets, and there's been an evolution. As I mentioned, Atkins deserves a lot of credit, but didn't have a lot of the science that I was fortunate to have when we developed our diets. But it was true, the Zone Diet was an advance, I think, over Atkins. I think Sugar Busters overall is an excellent book and diet. These have all been very popular. I think we're the next step on the evolution with more knowledge, and hopefully we'll keep up to date, and I'd be very happy to see other popular diets in the same vein. But I think the basic principles that good fats are good for you, and the good carbohydrates are good for you and the processed ones are not, I think that's current consensus of opinion.

Even with the American Heart Association?

The Heart Association is very much moving in this direction. They actually do not recommend the super low-fat, high-carbohydrate diets. They say avoid it because of the experience that you can actually touch off this pre-diabetes syndrome, including very high levels of triglycerides and low levels of good cholesterol. [In] their latest recommendation, they talk about the metabolic syndrome, and more about whole grains and whole foods. I think they are moving in the right direction.

Because when you first came out with this -- you write about this in the book a bit -- I mean, you were the rebel. You were up against the low-fat American Heart Association orthodoxy here.

Yeah. Early on, there were cardiologists running around saying our diet would kill people. And we were rebels. At this point, I really think the South Beach Diet represents the consensus of opinion, and I've not seen any criticism that I would consider really substantive.

For 30 years [the American Heart Association] recommended the low-fat diet, with hundreds of studies to back it up.

No, they don't have any studies to back it up.

The American Heart Association has been wrong for 30 years?

Yes. After World War II, 1950s, Dr. Ancel Keys from University of Minnesota did cross-country studies, where he found northern European countries were very high fat, high cholesterol, high heart attack rate. The less developed countries were low fat, high carbohydrate, low cholesterol, low heart attack rate. And from those population studies and some animal studies, it was felt that low fat, high carbohydrate was the way to go. At that time, they did not understand the concept of fiber or glycemic index or good fats. They didn't distinguish between the good and the bad fats.

There was an option to do a prospective study. Diet studies are much harder to do than vitamin studies. You can give placebo to one group and vitamin E to another group, and compare it. But you can't blind people from what they're eating, and compliance is very difficult. They're very difficult studies and very, very expensive. They simply decided not to do that large prospective study. They made recommendations on the best evidence that they had at the time.

It turned out the evidence was very misleading. The Harvard School of Public Health went back and did studies where, once they had the concept of fiber, adjusting for fiber. And they found that fat, even total fat, was much less important than originally thought. And there was always the exception of the island of Crete that was studied, which was high Mediterranean fat, and the population did very well, and the Greenland Eskimos, which were studied, which were high in, of course, fish oil fat, and also did very, very well. …

Do you think hunger is a red herring?

I think people actually are eating all the time because they're hungry all the time. Dr. David Ludwig in Boston did a very interesting study with overweight teenagers, where they fed them a high glycemic, sugary type breakfast versus a low glycemic, more slowly digested breakfast, and then over the next five hours, allowed them to choose their foods, eat whatever they wanted. The higher glycemic breakfast eaters actually consumed 80 percent more calories over the next five hours, and they switched around the kids, and the groups, and they found the same thing. Other studies have shown this, that we're hungry because of the swings in blood sugar and because of the types of carbohydrates that we're consuming.

So you eat breakfast and you eat a reasonable breakfast that's going to fill you up, sustain you longer.

Yes. And one problem in the schools today is, when kids are either skipping breakfast or eating junk for breakfast, with the swings in blood sugar, they're sleepy, they're tired, there's bad behavior. I've heard from teachers that after lunch, they get sort of a sugar high and they're bouncing off the walls. I think if we were feeding our children better, not only would they be thinner, but I think they would perform better in school and may be less behavior problems. …

How serious a problem really is this, that Americans are becoming more and more overweight? Especially young people.

Well, it's a problem for individuals, not only getting heart disease, heart attacks and strokes, but also orthopedic problems; they're more likely to have joint problems; they're more likely to get cancer, to not function well, to be tired during the day; there's sleep apnea, where they don't get enough sleep and are tired all day. So there're multiple problems from the individual basis. Nationally, economically, it's a huge problem because of lost work days, because of hospitalizations.

It's becoming an international problem. We're exporting these processed carbohydrates and fast foods all over the world, and many societies are not as capable as we are of consuming these high carbohydrate, high processed carbohydrate foods. Countries where there have been famine in recent times, underdeveloped countries, have a much bigger problem with processed carbohydrates than Americans do. They have epidemic obesity and diabetes. And in this country, the heaviest cities -- Houston is, I believe, the heaviest now -- and that's where there's been a lot of Mexican immigrants from northern Mexico, where they have a very large dose of this insulin resistant gene. They gain a little weight from processed food, they don't handle insulin well, and it becomes a vicious cycle. …

[What about] the idea that a low-fat diet is healthy is ingrained? You might lose weight on Atkins, but it can't be good for your health.

It's simply wrong. Low fat study after low fat study did not show decrease in heart attack and stroke, from what was called the Mr. Fit study to many other studies. The only ones that did were those that included a lot of fish. The Oslo Heart Study, which included fish consumption and smoking cessation, is the one low fat study people refer to. But most of the low fat studies absolutely did not show decrease in heart attack and stroke. The only [large] diet study that really has was the Lyon Heart Study, where they added the good fats. The benefits of the good fats is very well accepted, and it's hard to knock having whole foods, veggies, and whole grains. So we feel we're on very solid scientific ground.

Basically what you're saying is that during this period of low fat orthodoxy in the medical community, America has been getting bigger and bigger and bigger.

Yeah. Absolutely. And that's what we talked about. It was really an unintended experiment. No other society ever consumed this level of processed carbohydrates. Again, [there]'d been high fat societies as well as low fat societies that have done well. But there was never a society where we had high processed carbohydrate until the United States in the 1980s and 90s. And the result has been disastrous.

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posted april 8, 2004

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